From patchwork Tue Jul 7 20:12:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11649973 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6A62714E3 for ; Tue, 7 Jul 2020 20:12:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43943206BE for ; Tue, 7 Jul 2020 20:12:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="fmFnnt+e" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728422AbgGGUMp (ORCPT ); Tue, 7 Jul 2020 16:12:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726763AbgGGUMp (ORCPT ); Tue, 7 Jul 2020 16:12:45 -0400 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC9DBC061755 for ; Tue, 7 Jul 2020 13:12:43 -0700 (PDT) Received: by mail-wr1-x444.google.com with SMTP id a6so46607781wrm.4 for ; Tue, 07 Jul 2020 13:12:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=+zqqvyi3z5A21ql34E5+vQaCHF2rAOOJAQR+upY9QO0=; b=fmFnnt+ehdq4yzSf5JNaqXX4yhCqAqD0kK0/qt4eB91lTy43C9BV8NE2+7bCE2dMEV j/iYq+xbAyWSUJE96U9SszSPGm8fuSDz412xfxFWlqIfJCVtYRTbtJZuwBEimFPr2Jzq SZeC88b3d2af3OnObiDD64/C7gkdSt0cAFrRU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+zqqvyi3z5A21ql34E5+vQaCHF2rAOOJAQR+upY9QO0=; b=USJQ4uD+z9UqF8yELfhYxqe/AQzScw5md08/BVIErkCrHfwqcsjFvlithh5e8NAJv4 IrmfwQVRwWfL6tfUqvf7xsKn3gxVQEbb++hx1JO0ElhxDWaAYf3lhx0CK5jfwJ9mcXzP 2xwlg2TnccHut7pTCNnztlbm963EA4CNxqvJ7NqwuT34GpjY2ztptbhz0XTncwkQLgXt rM5TRCrWE7deQD7GopB2uc6tMMbBPi8EqyGagNBxuklRXrBHUIlPH+psGz53+8F7L5DC 8puXI7C1MwepZF+kwtK9J6da89h0jscBHgQdbNqHLXFWentlOo80v4A7le7yARSMOqN4 ud0A== X-Gm-Message-State: AOAM530M6rCjI3O5RNmCvhrIe28ru9mcy/2AOjUck8/2jVXqi70rcjKB qQV6ZNEv4/L+fcCJH57DfJbigw== X-Google-Smtp-Source: ABdhPJzrfZJXwmqAifF26fj/gQn6kFUlKzxT6On6Iaf8irG4na4G4iK3mAJTIWo1H7s/v1Eotv4TeA== X-Received: by 2002:adf:cf0c:: with SMTP id o12mr54938782wrj.265.1594152762369; Tue, 07 Jul 2020 13:12:42 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q7sm2515262wra.56.2020.07.07.13.12.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 13:12:41 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , Felix Kuehling , =?utf-8?q?Thomas_Hellstr=C3=B6m?= , Maarten Lankhorst , Mika Kuoppala , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , =?utf-8?q?Christian_K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 01/25] dma-fence: basic lockdep annotations Date: Tue, 7 Jul 2020 22:12:05 +0200 Message-Id: <20200707201229.472834-2-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Design is similar to the lockdep annotations for workers, but with some twists: - We use a read-lock for the execution/worker/completion side, so that this explicit annotation can be more liberally sprinkled around. With read locks lockdep isn't going to complain if the read-side isn't nested the same way under all circumstances, so ABBA deadlocks are ok. Which they are, since this is an annotation only. - We're using non-recursive lockdep read lock mode, since in recursive read lock mode lockdep does not catch read side hazards. And we _very_ much want read side hazards to be caught. For full details of this limitation see commit e91498589746065e3ae95d9a00b068e525eec34f Author: Peter Zijlstra Date: Wed Aug 23 13:13:11 2017 +0200 locking/lockdep/selftests: Add mixed read-write ABBA tests - To allow nesting of the read-side explicit annotations we explicitly keep track of the nesting. lock_is_held() allows us to do that. - The wait-side annotation is a write lock, and entirely done within dma_fence_wait() for everyone by default. - To be able to freely annotate helper functions I want to make it ok to call dma_fence_begin/end_signalling from soft/hardirq context. First attempt was using the hardirq locking context for the write side in lockdep, but this forces all normal spinlocks nested within dma_fence_begin/end_signalling to be spinlocks. That bollocks. The approach now is to simple check in_atomic(), and for these cases entirely rely on the might_sleep() check in dma_fence_wait(). That will catch any wrong nesting against spinlocks from soft/hardirq contexts. The idea here is that every code path that's critical for eventually signalling a dma_fence should be annotated with dma_fence_begin/end_signalling. The annotation ideally starts right after a dma_fence is published (added to a dma_resv, exposed as a sync_file fd, attached to a drm_syncobj fd, or anything else that makes the dma_fence visible to other kernel threads), up to and including the dma_fence_wait(). Examples are irq handlers, the scheduler rt threads, the tail of execbuf (after the corresponding fences are visible), any workers that end up signalling dma_fences and really anything else. Not annotated should be code paths that only complete fences opportunistically as the gpu progresses, like e.g. shrinker/eviction code. The main class of deadlocks this is supposed to catch are: Thread A: mutex_lock(A); mutex_unlock(A); dma_fence_signal(); Thread B: mutex_lock(A); dma_fence_wait(); mutex_unlock(A); Thread B is blocked on A signalling the fence, but A never gets around to that because it cannot acquire the lock A. Note that dma_fence_wait() is allowed to be nested within dma_fence_begin/end_signalling sections. To allow this to happen the read lock needs to be upgraded to a write lock, which means that any other lock is acquired between the dma_fence_begin_signalling() call and the call to dma_fence_wait(), and still held, this will result in an immediate lockdep complaint. The only other option would be to not annotate such calls, defeating the point. Therefore these annotations cannot be sprinkled over the code entirely mindless to avoid false positives. Originally I hope that the cross-release lockdep extensions would alleviate the need for explicit annotations: https://lwn.net/Articles/709849/ But there's a few reasons why that's not an option: - It's not happening in upstream, since it got reverted due to too many false positives: commit e966eaeeb623f09975ef362c2866fae6f86844f9 Author: Ingo Molnar Date: Tue Dec 12 12:31:16 2017 +0100 locking/lockdep: Remove the cross-release locking checks This code (CONFIG_LOCKDEP_CROSSRELEASE=y and CONFIG_LOCKDEP_COMPLETIONS=y), while it found a number of old bugs initially, was also causing too many false positives that caused people to disable lockdep - which is arguably a worse overall outcome. - cross-release uses the complete() call to annotate the end of critical sections, for dma_fence that would be dma_fence_signal(). But we do not want all dma_fence_signal() calls to be treated as critical, since many are opportunistic cleanup of gpu requests. If these get stuck there's still the main completion interrupt and workers who can unblock everyone. Automatically annotating all dma_fence_signal() calls would hence cause false positives. - cross-release had some educated guesses for when a critical section starts, like fresh syscall or fresh work callback. This would again cause false positives without explicit annotations, since for dma_fence the critical sections only starts when we publish a fence. - Furthermore there can be cases where a thread never does a dma_fence_signal, but is still critical for reaching completion of fences. One example would be a scheduler kthread which picks up jobs and pushes them into hardware, where the interrupt handler or another completion thread calls dma_fence_signal(). But if the scheduler thread hangs, then all the fences hang, hence we need to manually annotate it. cross-release aimed to solve this by chaining cross-release dependencies, but the dependency from scheduler thread to the completion interrupt handler goes through hw where cross-release code can't observe it. In short, without manual annotations and careful review of the start and end of critical sections, cross-relese dependency tracking doesn't work. We need explicit annotations. v2: handle soft/hardirq ctx better against write side and dont forget EXPORT_SYMBOL, drivers can't use this otherwise. v3: Kerneldoc. v4: Some spelling fixes from Mika v5: Amend commit message to explain in detail why cross-release isn't the solution. v6: Pull out misplaced .rst hunk. Cc: Felix Kuehling Reviewed-by: Thomas Hellström Reviewed-by: Maarten Lankhorst Cc: Mika Kuoppala Cc: Thomas Hellstrom Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter Acked-by: Dave Airlie for the first 2 + --- Documentation/driver-api/dma-buf.rst | 6 + drivers/dma-buf/dma-fence.c | 161 +++++++++++++++++++++++++++ include/linux/dma-fence.h | 12 ++ 3 files changed, 179 insertions(+) diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst index 7fb7b661febd..05d856131140 100644 --- a/Documentation/driver-api/dma-buf.rst +++ b/Documentation/driver-api/dma-buf.rst @@ -133,6 +133,12 @@ DMA Fences .. kernel-doc:: drivers/dma-buf/dma-fence.c :doc: DMA fences overview +DMA Fence Signalling Annotations +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/dma-buf/dma-fence.c + :doc: fence signalling annotation + DMA Fences Functions Reference ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 656e9ac2d028..0005bc002529 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -110,6 +110,160 @@ u64 dma_fence_context_alloc(unsigned num) } EXPORT_SYMBOL(dma_fence_context_alloc); +/** + * DOC: fence signalling annotation + * + * Proving correctness of all the kernel code around &dma_fence through code + * review and testing is tricky for a few reasons: + * + * * It is a cross-driver contract, and therefore all drivers must follow the + * same rules for lock nesting order, calling contexts for various functions + * and anything else significant for in-kernel interfaces. But it is also + * impossible to test all drivers in a single machine, hence brute-force N vs. + * N testing of all combinations is impossible. Even just limiting to the + * possible combinations is infeasible. + * + * * There is an enormous amount of driver code involved. For render drivers + * there's the tail of command submission, after fences are published, + * scheduler code, interrupt and workers to process job completion, + * and timeout, gpu reset and gpu hang recovery code. Plus for integration + * with core mm with have &mmu_notifier, respectively &mmu_interval_notifier, + * and &shrinker. For modesetting drivers there's the commit tail functions + * between when fences for an atomic modeset are published, and when the + * corresponding vblank completes, including any interrupt processing and + * related workers. Auditing all that code, across all drivers, is not + * feasible. + * + * * Due to how many other subsystems are involved and the locking hierarchies + * this pulls in there is extremely thin wiggle-room for driver-specific + * differences. &dma_fence interacts with almost all of the core memory + * handling through page fault handlers via &dma_resv, dma_resv_lock() and + * dma_resv_unlock(). On the other side it also interacts through all + * allocation sites through &mmu_notifier and &shrinker. + * + * Furthermore lockdep does not handle cross-release dependencies, which means + * any deadlocks between dma_fence_wait() and dma_fence_signal() can't be caught + * at runtime with some quick testing. The simplest example is one thread + * waiting on a &dma_fence while holding a lock:: + * + * lock(A); + * dma_fence_wait(B); + * unlock(A); + * + * while the other thread is stuck trying to acquire the same lock, which + * prevents it from signalling the fence the previous thread is stuck waiting + * on:: + * + * lock(A); + * unlock(A); + * dma_fence_signal(B); + * + * By manually annotating all code relevant to signalling a &dma_fence we can + * teach lockdep about these dependencies, which also helps with the validation + * headache since now lockdep can check all the rules for us:: + * + * cookie = dma_fence_begin_signalling(); + * lock(A); + * unlock(A); + * dma_fence_signal(B); + * dma_fence_end_signalling(cookie); + * + * For using dma_fence_begin_signalling() and dma_fence_end_signalling() to + * annotate critical sections the following rules need to be observed: + * + * * All code necessary to complete a &dma_fence must be annotated, from the + * point where a fence is accessible to other threads, to the point where + * dma_fence_signal() is called. Un-annotated code can contain deadlock issues, + * and due to the very strict rules and many corner cases it is infeasible to + * catch these just with review or normal stress testing. + * + * * &struct dma_resv deserves a special note, since the readers are only + * protected by rcu. This means the signalling critical section starts as soon + * as the new fences are installed, even before dma_resv_unlock() is called. + * + * * The only exception are fast paths and opportunistic signalling code, which + * calls dma_fence_signal() purely as an optimization, but is not required to + * guarantee completion of a &dma_fence. The usual example is a wait IOCTL + * which calls dma_fence_signal(), while the mandatory completion path goes + * through a hardware interrupt and possible job completion worker. + * + * * To aid composability of code, the annotations can be freely nested, as long + * as the overall locking hierarchy is consistent. The annotations also work + * both in interrupt and process context. Due to implementation details this + * requires that callers pass an opaque cookie from + * dma_fence_begin_signalling() to dma_fence_end_signalling(). + * + * * Validation against the cross driver contract is implemented by priming + * lockdep with the relevant hierarchy at boot-up. This means even just + * testing with a single device is enough to validate a driver, at least as + * far as deadlocks with dma_fence_wait() against dma_fence_signal() are + * concerned. + */ +#ifdef CONFIG_LOCKDEP +struct lockdep_map dma_fence_lockdep_map = { + .name = "dma_fence_map" +}; + +/** + * dma_fence_begin_signalling - begin a critical DMA fence signalling section + * + * Drivers should use this to annotate the beginning of any code section + * required to eventually complete &dma_fence by calling dma_fence_signal(). + * + * The end of these critical sections are annotated with + * dma_fence_end_signalling(). + * + * Returns: + * + * Opaque cookie needed by the implementation, which needs to be passed to + * dma_fence_end_signalling(). + */ +bool dma_fence_begin_signalling(void) +{ + /* explicitly nesting ... */ + if (lock_is_held_type(&dma_fence_lockdep_map, 1)) + return true; + + /* rely on might_sleep check for soft/hardirq locks */ + if (in_atomic()) + return true; + + /* ... and non-recursive readlock */ + lock_acquire(&dma_fence_lockdep_map, 0, 0, 1, 1, NULL, _RET_IP_); + + return false; +} +EXPORT_SYMBOL(dma_fence_begin_signalling); + +/** + * dma_fence_end_signalling - end a critical DMA fence signalling section + * + * Closes a critical section annotation opened by dma_fence_begin_signalling(). + */ +void dma_fence_end_signalling(bool cookie) +{ + if (cookie) + return; + + lock_release(&dma_fence_lockdep_map, _RET_IP_); +} +EXPORT_SYMBOL(dma_fence_end_signalling); + +void __dma_fence_might_wait(void) +{ + bool tmp; + + tmp = lock_is_held_type(&dma_fence_lockdep_map, 1); + if (tmp) + lock_release(&dma_fence_lockdep_map, _THIS_IP_); + lock_map_acquire(&dma_fence_lockdep_map); + lock_map_release(&dma_fence_lockdep_map); + if (tmp) + lock_acquire(&dma_fence_lockdep_map, 0, 0, 1, 1, NULL, _THIS_IP_); +} +#endif + + /** * dma_fence_signal_locked - signal completion of a fence * @fence: the fence to signal @@ -170,14 +324,19 @@ int dma_fence_signal(struct dma_fence *fence) { unsigned long flags; int ret; + bool tmp; if (!fence) return -EINVAL; + tmp = dma_fence_begin_signalling(); + spin_lock_irqsave(fence->lock, flags); ret = dma_fence_signal_locked(fence); spin_unlock_irqrestore(fence->lock, flags); + dma_fence_end_signalling(tmp); + return ret; } EXPORT_SYMBOL(dma_fence_signal); @@ -210,6 +369,8 @@ dma_fence_wait_timeout(struct dma_fence *fence, bool intr, signed long timeout) might_sleep(); + __dma_fence_might_wait(); + trace_dma_fence_wait_start(fence); if (fence->ops->wait) ret = fence->ops->wait(fence, intr, timeout); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 3347c54f3a87..3f288f7db2ef 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -357,6 +357,18 @@ dma_fence_get_rcu_safe(struct dma_fence __rcu **fencep) } while (1); } +#ifdef CONFIG_LOCKDEP +bool dma_fence_begin_signalling(void); +void dma_fence_end_signalling(bool cookie); +#else +static inline bool dma_fence_begin_signalling(void) +{ + return true; +} +static inline void dma_fence_end_signalling(bool cookie) {} +static inline void __dma_fence_might_wait(void) {} +#endif + int dma_fence_signal(struct dma_fence *fence); int dma_fence_signal_locked(struct dma_fence *fence); signed long dma_fence_default_wait(struct dma_fence *fence, From patchwork Tue Jul 7 20:12:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11649979 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8A15014E3 for ; Tue, 7 Jul 2020 20:12:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B41E206C3 for ; Tue, 7 Jul 2020 20:12:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="gGyNx0i3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728500AbgGGUMr (ORCPT ); Tue, 7 Jul 2020 16:12:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728231AbgGGUMq (ORCPT ); Tue, 7 Jul 2020 16:12:46 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31885C08C5E1 for ; Tue, 7 Jul 2020 13:12:45 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id b6so46583131wrs.11 for ; Tue, 07 Jul 2020 13:12:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=UQmLZnah7bfhRPk6a+CvrO+Hrcg0i+nu2RXhpocXquc=; b=gGyNx0i3MF17cU0chLjsFFwVNMQq05YMcV8zGhsAK0r3IqA+FME6EZp20CKLJoq3E7 xTt5FCheDzBPrYieMn7Xk4VV/DiXSHER50RO0f+XPHO8Ns1kmi/ER1Lu0qG1sUzKHqcj hRYj7Pqj5QSilZIv/IOKUxTjskMFkhle5hZzI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=UQmLZnah7bfhRPk6a+CvrO+Hrcg0i+nu2RXhpocXquc=; 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This is fundamental to how eviction works with ttm, so required. - it is allowed to call dma_fence_wait() from memory reclaim contexts, specifically from shrinker callbacks (which i915 does), and from mmu notifier callbacks (which amdgpu does, and which i915 sometimes also does, and probably always should, but that's kinda a debate). Also for stuff like HMM we really need to be able to do this, or things get real dicey. Consequence is that any critical path necessary to get to a dma_fence_signal for a fence must never a) call dma_resv_lock nor b) allocate memory with GFP_KERNEL. Also by implication of dma_resv_lock(), no userspace faulting allowed. That's some supremely obnoxious limitations, which is why we need to sprinkle the right annotations to all relevant paths. The one big locking context we're leaving out here is mmu notifiers, added in commit 23b68395c7c78a764e8963fc15a7cfd318bf187f Author: Daniel Vetter Date: Mon Aug 26 22:14:21 2019 +0200 mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end that one covers a lot of other callsites, and it's also allowed to wait on dma-fences from mmu notifiers. But there's no ready-made functions exposed to prime this, so I've left it out for now. v2: Also track against mmu notifier context. v3: kerneldoc to spec the cross-driver contract. Note that currently i915 throws in a hard-coded 10s timeout on foreign fences (not sure why that was done, but it's there), which is why that rule is worded with SHOULD instead of MUST. Also some of the mmu_notifier/shrinker rules might surprise SoC drivers, I haven't fully audited them all. Which is infeasible anyway, we'll need to run them with lockdep and dma-fence annotations and see what goes boom. v4: A spelling fix from Mika v5: #ifdef for CONFIG_MMU_NOTIFIER. Reported by 0day. Unfortunately this means lockdep enforcement is slightly inconsistent, it won't spot GFP_NOIO and GFP_NOFS allocations in the wrong spot if CONFIG_MMU_NOTIFIER is disabled in the kernel config. Oh well. v5: Note that only drivers/gpu has a reasonable (or at least historical) excuse to use dma_fence_wait() from shrinker and mmu notifier callbacks. Everyone else should either have a better memory manager model, or better hardware. This reflects discussions with Jason Gunthorpe. Cc: Jason Gunthorpe Cc: Felix Kuehling Cc: kernel test robot Reviewed-by: Thomas Hellström (v4) Cc: Mika Kuoppala Cc: Thomas Hellstrom Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- Documentation/driver-api/dma-buf.rst | 6 ++++ drivers/dma-buf/dma-fence.c | 46 ++++++++++++++++++++++++++++ drivers/dma-buf/dma-resv.c | 8 +++++ include/linux/dma-fence.h | 1 + 4 files changed, 61 insertions(+) diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst index 05d856131140..f8f6decde359 100644 --- a/Documentation/driver-api/dma-buf.rst +++ b/Documentation/driver-api/dma-buf.rst @@ -133,6 +133,12 @@ DMA Fences .. kernel-doc:: drivers/dma-buf/dma-fence.c :doc: DMA fences overview +DMA Fence Cross-Driver Contract +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/dma-buf/dma-fence.c + :doc: fence cross-driver contract + DMA Fence Signalling Annotations ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 0005bc002529..af1d8ea926b3 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -64,6 +64,52 @@ static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1); * &dma_buf.resv pointer. */ +/** + * DOC: fence cross-driver contract + * + * Since &dma_fence provide a cross driver contract, all drivers must follow the + * same rules: + * + * * Fences must complete in a reasonable time. Fences which represent kernels + * and shaders submitted by userspace, which could run forever, must be backed + * up by timeout and gpu hang recovery code. Minimally that code must prevent + * further command submission and force complete all in-flight fences, e.g. + * when the driver or hardware do not support gpu reset, or if the gpu reset + * failed for some reason. Ideally the driver supports gpu recovery which only + * affects the offending userspace context, and no other userspace + * submissions. + * + * * Drivers may have different ideas of what completion within a reasonable + * time means. Some hang recovery code uses a fixed timeout, others a mix + * between observing forward progress and increasingly strict timeouts. + * Drivers should not try to second guess timeout handling of fences from + * other drivers. + * + * * To ensure there's no deadlocks of dma_fence_wait() against other locks + * drivers should annotate all code required to reach dma_fence_signal(), + * which completes the fences, with dma_fence_begin_signalling() and + * dma_fence_end_signalling(). + * + * * Drivers are allowed to call dma_fence_wait() while holding dma_resv_lock(). + * This means any code required for fence completion cannot acquire a + * &dma_resv lock. Note that this also pulls in the entire established + * locking hierarchy around dma_resv_lock() and dma_resv_unlock(). + * + * * Drivers are allowed to call dma_fence_wait() from their &shrinker + * callbacks. This means any code required for fence completion cannot + * allocate memory with GFP_KERNEL. + * + * * Drivers are allowed to call dma_fence_wait() from their &mmu_notifier + * respectively &mmu_interval_notifier callbacks. This means any code required + * for fence completeion cannot allocate memory with GFP_NOFS or GFP_NOIO. + * Only GFP_ATOMIC is permissible, which might fail. + * + * Note that only GPU drivers have a reasonable excuse for both requiring + * &mmu_interval_notifier and &shrinker callbacks at the same time as having to + * track asynchronous compute work using &dma_fence. No driver outside of + * drivers/gpu should ever call dma_fence_wait() in such contexts. + */ + static const char *dma_fence_stub_get_name(struct dma_fence *fence) { return "stub"; diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index e7d7197d48ce..0e6675ec1d11 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -36,6 +36,7 @@ #include #include #include +#include /** * DOC: Reservation Object Overview @@ -116,6 +117,13 @@ static int __init dma_resv_lockdep(void) if (ret == -EDEADLK) dma_resv_lock_slow(&obj, &ctx); fs_reclaim_acquire(GFP_KERNEL); +#ifdef CONFIG_MMU_NOTIFIER + lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); + __dma_fence_might_wait(); + lock_map_release(&__mmu_notifier_invalidate_range_start_map); +#else + __dma_fence_might_wait(); +#endif fs_reclaim_release(GFP_KERNEL); ww_mutex_unlock(&obj.lock); ww_acquire_fini(&ctx); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 3f288f7db2ef..09e23adb351d 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -360,6 +360,7 @@ dma_fence_get_rcu_safe(struct dma_fence __rcu **fencep) #ifdef CONFIG_LOCKDEP bool dma_fence_begin_signalling(void); void dma_fence_end_signalling(bool cookie); +void __dma_fence_might_wait(void); #else static inline bool dma_fence_begin_signalling(void) { From patchwork Tue Jul 7 20:12:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11649983 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B6FB692A for ; Tue, 7 Jul 2020 20:12:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A42A20720 for ; Tue, 7 Jul 2020 20:12:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="i4Wbb9D5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728508AbgGGUMr (ORCPT ); Tue, 7 Jul 2020 16:12:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728303AbgGGUMq (ORCPT ); Tue, 7 Jul 2020 16:12:46 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94308C08C5DC for ; Tue, 7 Jul 2020 13:12:46 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id z15so35313410wrl.8 for ; Tue, 07 Jul 2020 13:12:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=UGBGWvdQ7uikeFllACLNz+UTtRSJGowmgwCHMdSNNLo=; b=i4Wbb9D5vWR7ZvrtLwuYGSomQJsW13PdSzmWff3tCkJHGhMCGQ/HSW5yxVH79pV46L tGbdgX4hG3qDBztTT4nSZm/jRw+NGvkWAW3puj/5aI3ocSr0a9lVgHUIRWXjL5Q4bmcC ymy40QVqyUlP61mFf/kASiA4K6cTSnd36TinU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=UGBGWvdQ7uikeFllACLNz+UTtRSJGowmgwCHMdSNNLo=; 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What I'm not sure about is whether the text should be more explicit in flat out mandating the amdkfd eviction fences for long running compute workloads or workloads where userspace fencing is allowed. v2: Now with dot graph! Cc: Jesse Natalie Cc: Steve Pronovost Cc: Jason Ekstrand Cc: Felix Kuehling Cc: Mika Kuoppala Cc: Thomas Hellstrom Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter Acked-by: Daniel Stone Acked-by: Christian König --- Documentation/driver-api/dma-buf.rst | 70 ++++++++++++++++++++++++ drivers/gpu/drm/virtio/virtgpu_display.c | 20 ------- 2 files changed, 70 insertions(+), 20 deletions(-) diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst index f8f6decde359..037ba0078bb4 100644 --- a/Documentation/driver-api/dma-buf.rst +++ b/Documentation/driver-api/dma-buf.rst @@ -178,3 +178,73 @@ DMA Fence uABI/Sync File .. kernel-doc:: include/linux/sync_file.h :internal: +Idefinite DMA Fences +~~~~~~~~~~~~~~~~~~~~ + +At various times &dma_fence with an indefinite time until dma_fence_wait() +finishes have been proposed. Examples include: + +* Future fences, used in HWC1 to signal when a buffer isn't used by the display + any longer, and created with the screen update that makes the buffer visible. + The time this fence completes is entirely under userspace's control. + +* Proxy fences, proposed to handle &drm_syncobj for which the fence has not yet + been set. Used to asynchronously delay command submission. + +* Userspace fences or gpu futexes, fine-grained locking within a command buffer + that userspace uses for synchronization across engines or with the CPU, which + are then imported as a DMA fence for integration into existing winsys + protocols. + +* Long-running compute command buffers, while still using traditional end of + batch DMA fences for memory management instead of context preemption DMA + fences which get reattached when the compute job is rescheduled. + +Common to all these schemes is that userspace controls the dependencies of these +fences and controls when they fire. Mixing indefinite fences with normal +in-kernel DMA fences does not work, even when a fallback timeout is included to +protect against malicious userspace: + +* Only the kernel knows about all DMA fence dependencies, userspace is not aware + of dependencies injected due to memory management or scheduler decisions. + +* Only userspace knows about all dependencies in indefinite fences and when + exactly they will complete, the kernel has no visibility. + +Furthermore the kernel has to be able to hold up userspace command submission +for memory management needs, which means we must support indefinite fences being +dependent upon DMA fences. If the kernel also support indefinite fences in the +kernel like a DMA fence, like any of the above proposal would, there is the +potential for deadlocks. + +.. kernel-render:: DOT + :alt: Indefinite Fencing Dependency Cycle + :caption: Indefinite Fencing Dependency Cycle + + digraph "Fencing Cycle" { + node [shape=box bgcolor=grey style=filled] + kernel [label="Kernel DMA Fences"] + userspace [label="userspace controlled fences"] + kernel -> userspace [label="memory management"] + userspace -> kernel [label="Future fence, fence proxy, ..."] + + { rank=same; kernel userspace } + } + +This means that the kernel might accidentally create deadlocks +through memory management dependencies which userspace is unaware of, which +randomly hangs workloads until the timeout kicks in. Workloads, which from +userspace's perspective, do not contain a deadlock. In such a mixed fencing +architecture there is no single entity with knowledge of all dependencies. +Thefore preventing such deadlocks from within the kernel is not possible. + +The only solution to avoid dependencies loops is by not allowing indefinite +fences in the kernel. This means: + +* No future fences, proxy fences or userspace fences imported as DMA fences, + with or without a timeout. + +* No DMA fences that signal end of batchbuffer for command submission where + userspace is allowed to use userspace fencing or long running compute + workloads. This also means no implicit fencing for shared buffers in these + cases. diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c index f3ce49c5a34c..af55b334be2f 100644 --- a/drivers/gpu/drm/virtio/virtgpu_display.c +++ b/drivers/gpu/drm/virtio/virtgpu_display.c @@ -314,25 +314,6 @@ virtio_gpu_user_framebuffer_create(struct drm_device *dev, return &virtio_gpu_fb->base; } -static void vgdev_atomic_commit_tail(struct drm_atomic_state *state) -{ - struct drm_device *dev = state->dev; - - drm_atomic_helper_commit_modeset_disables(dev, state); - drm_atomic_helper_commit_modeset_enables(dev, state); - drm_atomic_helper_commit_planes(dev, state, 0); - - drm_atomic_helper_fake_vblank(state); - drm_atomic_helper_commit_hw_done(state); - - drm_atomic_helper_wait_for_vblanks(dev, state); - drm_atomic_helper_cleanup_planes(dev, state); -} - -static const struct drm_mode_config_helper_funcs virtio_mode_config_helpers = { - .atomic_commit_tail = vgdev_atomic_commit_tail, -}; - static const struct drm_mode_config_funcs virtio_gpu_mode_funcs = { .fb_create = virtio_gpu_user_framebuffer_create, .atomic_check = drm_atomic_helper_check, @@ -346,7 +327,6 @@ void virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev) drm_mode_config_init(vgdev->ddev); vgdev->ddev->mode_config.quirk_addfb_prefer_host_byte_order = true; vgdev->ddev->mode_config.funcs = &virtio_gpu_mode_funcs; - vgdev->ddev->mode_config.helper_private = &virtio_mode_config_helpers; /* modes will be validated against the framebuffer size */ vgdev->ddev->mode_config.min_width = XRES_MIN; From patchwork Tue Jul 7 20:12:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11649995 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1DA8614E3 for ; Tue, 7 Jul 2020 20:12:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0281620720 for ; 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Tue, 07 Jul 2020 13:12:46 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q7sm2515262wra.56.2020.07.07.13.12.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 13:12:46 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter , Rodrigo Siqueira , Haneen Mohammed , Daniel Vetter Subject: [PATCH 04/25] drm/vkms: Annotate vblank timer Date: Tue, 7 Jul 2020 22:12:08 +0200 Message-Id: <20200707201229.472834-5-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This is needed to signal the fences from page flips, annotate it accordingly. We need to annotate entire timer callback since if we get stuck anywhere in there, then the timer stops, and hence fences stop. Just annotating the top part that does the vblank handling isn't enough. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter Cc: Rodrigo Siqueira Cc: Haneen Mohammed Cc: Daniel Vetter Reviewed-by: Rodrigo Siqueira Tested-by: Melissa Wen --- drivers/gpu/drm/vkms/vkms_crtc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c index ac85e17428f8..a53a40848a72 100644 --- a/drivers/gpu/drm/vkms/vkms_crtc.c +++ b/drivers/gpu/drm/vkms/vkms_crtc.c @@ -1,5 +1,7 @@ // SPDX-License-Identifier: GPL-2.0+ +#include + #include #include #include @@ -14,7 +16,9 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) struct drm_crtc *crtc = &output->crtc; struct vkms_crtc_state *state; u64 ret_overrun; - bool ret; + bool ret, fence_cookie; + + fence_cookie = dma_fence_begin_signalling(); ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer, output->period_ns); @@ -49,6 +53,8 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) DRM_DEBUG_DRIVER("Composer worker already queued\n"); } + dma_fence_end_signalling(fence_cookie); + return HRTIMER_RESTART; } From patchwork Tue Jul 7 20:12:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11649993 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EE60B14DD for ; Tue, 7 Jul 2020 20:12:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D72EF206C3 for ; Tue, 7 Jul 2020 20:12:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="NYza4RHR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728578AbgGGUMu (ORCPT ); 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Tue, 07 Jul 2020 13:12:47 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 05/25] drm/vblank: Annotate with dma-fence signalling section Date: Tue, 7 Jul 2020 22:12:09 +0200 Message-Id: <20200707201229.472834-6-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This is rather overkill since currently all drivers call this from hardirq (or at least timers). But maybe in the future we're going to have thread irq handlers and what not, doesn't hurt to be prepared. Plus this is an easy start for sprinkling these fence annotations into shared code. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_vblank.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 42a84eb4cc8c..d681ab09963c 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -24,6 +24,7 @@ * OTHER DEALINGS IN THE SOFTWARE. */ +#include #include #include @@ -1909,7 +1910,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) { struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; unsigned long irqflags; - bool disable_irq; + bool disable_irq, fence_cookie; if (drm_WARN_ON_ONCE(dev, !drm_dev_has_vblank(dev))) return false; @@ -1917,6 +1918,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) if (drm_WARN_ON(dev, pipe >= dev->num_crtcs)) return false; + fence_cookie = dma_fence_begin_signalling(); + spin_lock_irqsave(&dev->event_lock, irqflags); /* Need timestamp lock to prevent concurrent execution with @@ -1929,6 +1932,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) if (!vblank->enabled) { spin_unlock(&dev->vblank_time_lock); spin_unlock_irqrestore(&dev->event_lock, irqflags); + dma_fence_end_signalling(fence_cookie); return false; } @@ -1954,6 +1958,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) if (disable_irq) vblank_disable_fn(&vblank->disable_timer); + dma_fence_end_signalling(fence_cookie); + return true; } EXPORT_SYMBOL(drm_handle_vblank); From patchwork Tue Jul 7 20:12:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11649999 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CD3EF14E3 for ; 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Tue, 07 Jul 2020 13:12:48 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q7sm2515262wra.56.2020.07.07.13.12.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 13:12:48 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 06/25] drm/amdgpu: add dma-fence annotations to atomic commit path Date: Tue, 7 Jul 2020 22:12:10 +0200 Message-Id: <20200707201229.472834-7-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org I need a canary in a ttm-based atomic driver to make sure the dma_fence_begin/end_signalling annotations actually work. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 5b0f708dd8c5..6afcc33ff846 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -57,6 +57,7 @@ #include "ivsrcid/ivsrcid_vislands30.h" +#include #include #include #include @@ -7359,6 +7360,9 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) struct drm_connector_state *old_con_state, *new_con_state; struct dm_crtc_state *dm_old_crtc_state, *dm_new_crtc_state; int crtc_disable_count = 0; + bool fence_cookie; + + fence_cookie = dma_fence_begin_signalling(); drm_atomic_helper_update_legacy_modeset_state(dev, state); @@ -7639,6 +7643,8 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) /* Signal HW programming completion */ drm_atomic_helper_commit_hw_done(state); + dma_fence_end_signalling(fence_cookie); + if (wait_for_vblank) drm_atomic_helper_wait_for_flip_done(dev, state); From patchwork Tue Jul 7 20:12:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650033 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A8E9214DD for ; Tue, 7 Jul 2020 20:13:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F427206C3 for ; Tue, 7 Jul 2020 20:13:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="LR4PlS7g" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728701AbgGGUNC (ORCPT ); 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Tue, 07 Jul 2020 13:12:59 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 16/25] drm/atomic-helper: Add dma-fence annotations Date: Tue, 7 Jul 2020 22:12:20 +0200 Message-Id: <20200707201229.472834-17-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This is a bit disappointing since we need to split the annotations over all the different parts. I was considering just leaking the critical section into the ->atomic_commit_tail callback of each driver. But that would mean we need to pass the fence_cookie into each driver (there's a total of 13 implementations of this hook right now), so bad flag day. And also a bit leaky abstraction. Hence just do it function-by-function. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_atomic_helper.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index c6bf9722b51b..f67ee513a7cc 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1550,6 +1550,7 @@ EXPORT_SYMBOL(drm_atomic_helper_wait_for_flip_done); void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state) { struct drm_device *dev = old_state->dev; + bool fence_cookie = dma_fence_begin_signalling(); drm_atomic_helper_commit_modeset_disables(dev, old_state); @@ -1561,6 +1562,8 @@ void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state) drm_atomic_helper_commit_hw_done(old_state); + dma_fence_end_signalling(fence_cookie); + drm_atomic_helper_wait_for_vblanks(dev, old_state); drm_atomic_helper_cleanup_planes(dev, old_state); @@ -1580,6 +1583,7 @@ EXPORT_SYMBOL(drm_atomic_helper_commit_tail); void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state) { struct drm_device *dev = old_state->dev; + bool fence_cookie = dma_fence_begin_signalling(); drm_atomic_helper_commit_modeset_disables(dev, old_state); @@ -1592,6 +1596,8 @@ void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state) drm_atomic_helper_commit_hw_done(old_state); + dma_fence_end_signalling(fence_cookie); + drm_atomic_helper_wait_for_vblanks(dev, old_state); drm_atomic_helper_cleanup_planes(dev, old_state); @@ -1607,6 +1613,9 @@ static void commit_tail(struct drm_atomic_state *old_state) ktime_t start; s64 commit_time_ms; unsigned int i, new_self_refresh_mask = 0; + bool fence_cookie; + + fence_cookie = dma_fence_begin_signalling(); funcs = dev->mode_config.helper_private; @@ -1635,6 +1644,8 @@ static void commit_tail(struct drm_atomic_state *old_state) if (new_crtc_state->self_refresh_active) new_self_refresh_mask |= BIT(i); + dma_fence_end_signalling(fence_cookie); + if (funcs && funcs->atomic_commit_tail) funcs->atomic_commit_tail(old_state); else @@ -1790,6 +1801,7 @@ int drm_atomic_helper_commit(struct drm_device *dev, bool nonblock) { int ret; + bool fence_cookie; if (state->async_update) { ret = drm_atomic_helper_prepare_planes(dev, state); @@ -1812,6 +1824,8 @@ int drm_atomic_helper_commit(struct drm_device *dev, if (ret) return ret; + fence_cookie = dma_fence_begin_signalling(); + if (!nonblock) { ret = drm_atomic_helper_wait_for_fences(dev, state, true); if (ret) @@ -1849,6 +1863,7 @@ int drm_atomic_helper_commit(struct drm_device *dev, */ drm_atomic_state_get(state); + dma_fence_end_signalling(fence_cookie); if (nonblock) queue_work(system_unbound_wq, &state->commit_work); else @@ -1857,6 +1872,7 @@ int drm_atomic_helper_commit(struct drm_device *dev, return 0; err: + dma_fence_end_signalling(fence_cookie); drm_atomic_helper_cleanup_planes(dev, state); return ret; } From patchwork Tue Jul 7 20:12:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650037 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CD84192A for ; Tue, 7 Jul 2020 20:13:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7E4620773 for ; Tue, 7 Jul 2020 20:13:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="NjaGAbSC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728693AbgGGUNE (ORCPT ); Tue, 7 Jul 2020 16:13:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728648AbgGGUND (ORCPT ); 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Add dma-fence annotations so that lockdep can check this for us. I've tried to quite carefully review this, and I think it's at the right spot. But obviosly no expert on drm scheduler. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/scheduler/sched_main.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index d6eaa23ad746..52f1ab4bc922 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -765,9 +765,12 @@ static int drm_sched_main(void *param) struct sched_param sparam = {.sched_priority = 1}; struct drm_gpu_scheduler *sched = (struct drm_gpu_scheduler *)param; int r; + bool fence_cookie; sched_setscheduler(current, SCHED_FIFO, &sparam); + fence_cookie = dma_fence_begin_signalling(); + while (!kthread_should_stop()) { struct drm_sched_entity *entity = NULL; struct drm_sched_fence *s_fence; @@ -825,6 +828,9 @@ static int drm_sched_main(void *param) wake_up(&sched->job_scheduled); } + + dma_fence_end_signalling(fence_cookie); + return 0; } From patchwork Tue Jul 7 20:12:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650043 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D720192A for ; Tue, 7 Jul 2020 20:13:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BEE542075B for ; Tue, 7 Jul 2020 20:13:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="exbtvFm/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728720AbgGGUNG (ORCPT ); Tue, 7 Jul 2020 16:13:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728648AbgGGUNF (ORCPT ); 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If we mix this up lockdep complaints, and that's again why we want to have these annotations. A nice side effect of this is that because of the fs_reclaim priming for dma_fence_enable lockdep now automatically checks for us that nothing in here allocates memory, without even running any userptr workloads. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index a512ccbc4dea..858528a06fe7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -1212,6 +1212,7 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, struct amdgpu_job *job; uint64_t seq; int r; + bool fence_cookie; job = p->job; p->job = NULL; @@ -1226,6 +1227,8 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, */ mutex_lock(&p->adev->notifier_lock); + fence_cookie = dma_fence_begin_signalling(); + /* If userptr are invalidated after amdgpu_cs_parser_bos(), return * -EAGAIN, drmIoctl in libdrm will restart the amdgpu_cs_ioctl. */ @@ -1262,12 +1265,14 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, amdgpu_vm_move_to_lru_tail(p->adev, &fpriv->vm); ttm_eu_fence_buffer_objects(&p->ticket, &p->validated, p->fence); + dma_fence_end_signalling(fence_cookie); mutex_unlock(&p->adev->notifier_lock); return 0; error_abort: drm_sched_job_cleanup(&job->base); + dma_fence_end_signalling(fence_cookie); mutex_unlock(&p->adev->notifier_lock); error_unlock: From patchwork Tue Jul 7 20:12:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650045 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4EAC214E3 for ; Tue, 7 Jul 2020 20:13:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3781C2075B for ; Tue, 7 Jul 2020 20:13:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="I+82JJmu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728722AbgGGUNG (ORCPT ); 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Tue, 07 Jul 2020 13:13:03 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 19/25] drm/amdgpu: s/GFP_KERNEL/GFP_ATOMIC in scheduler code Date: Tue, 7 Jul 2020 22:12:23 +0200 Message-Id: <20200707201229.472834-20-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org My dma-fence lockdep annotations caught an inversion because we allocate memory where we really shouldn't: kmem_cache_alloc+0x2b/0x6d0 amdgpu_fence_emit+0x30/0x330 [amdgpu] amdgpu_ib_schedule+0x306/0x550 [amdgpu] amdgpu_job_run+0x10f/0x260 [amdgpu] drm_sched_main+0x1b9/0x490 [gpu_sched] kthread+0x12e/0x150 Trouble right now is that lockdep only validates against GFP_FS, which would be good enough for shrinkers. But for mmu_notifiers we actually need !GFP_ATOMIC, since they can be called from any page laundering, even if GFP_NOFS or GFP_NOIO are set. I guess we should improve the lockdep annotations for fs_reclaim_acquire/release. Ofc real fix is to properly preallocate this fence and stuff it into the amdgpu job structure. But GFP_ATOMIC gets the lockdep splat out of the way. v2: Two more allocations in scheduler paths. Frist one: __kmalloc+0x58/0x720 amdgpu_vmid_grab+0x100/0xca0 [amdgpu] amdgpu_job_dependency+0xf9/0x120 [amdgpu] drm_sched_entity_pop_job+0x3f/0x440 [gpu_sched] drm_sched_main+0xf9/0x490 [gpu_sched] Second one: kmem_cache_alloc+0x2b/0x6d0 amdgpu_sync_fence+0x7e/0x110 [amdgpu] amdgpu_vmid_grab+0x86b/0xca0 [amdgpu] amdgpu_job_dependency+0xf9/0x120 [amdgpu] drm_sched_entity_pop_job+0x3f/0x440 [gpu_sched] drm_sched_main+0xf9/0x490 [gpu_sched] Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index 8d84975885cd..a089a827fdfe 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -143,7 +143,7 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f, uint32_t seq; int r; - fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL); + fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_ATOMIC); if (fence == NULL) return -ENOMEM; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c index 267fa45ddb66..a333ca2d4ddd 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c @@ -208,7 +208,7 @@ static int amdgpu_vmid_grab_idle(struct amdgpu_vm *vm, if (ring->vmid_wait && !dma_fence_is_signaled(ring->vmid_wait)) return amdgpu_sync_fence(sync, ring->vmid_wait); - fences = kmalloc_array(sizeof(void *), id_mgr->num_ids, GFP_KERNEL); + fences = kmalloc_array(sizeof(void *), id_mgr->num_ids, GFP_ATOMIC); if (!fences) return -ENOMEM; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c index 8ea6c49529e7..af22b526cec9 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c @@ -160,7 +160,7 @@ int amdgpu_sync_fence(struct amdgpu_sync *sync, struct dma_fence *f) if (amdgpu_sync_add_later(sync, f)) return 0; - e = kmem_cache_alloc(amdgpu_sync_slab, GFP_KERNEL); + e = kmem_cache_alloc(amdgpu_sync_slab, GFP_ATOMIC); if (!e) return -ENOMEM; From patchwork Tue Jul 7 20:12:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650051 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1DF5492A for ; Tue, 7 Jul 2020 20:13:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0460A2078D for ; Tue, 7 Jul 2020 20:13:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="GL5GXtMw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728734AbgGGUNI (ORCPT ); Tue, 7 Jul 2020 16:13:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728730AbgGGUNH (ORCPT ); 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Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/amd/amdgpu/atom.c | 2 +- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +- drivers/gpu/drm/amd/display/dc/core/dc.c | 4 +++- 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/atom.c b/drivers/gpu/drm/amd/amdgpu/atom.c index 4cfc786699c7..1b0c674fab25 100644 --- a/drivers/gpu/drm/amd/amdgpu/atom.c +++ b/drivers/gpu/drm/amd/amdgpu/atom.c @@ -1226,7 +1226,7 @@ static int amdgpu_atom_execute_table_locked(struct atom_context *ctx, int index, ectx.abort = false; ectx.last_jump = 0; if (ws) - ectx.ws = kcalloc(4, ws, GFP_KERNEL); + ectx.ws = kcalloc(4, ws, GFP_ATOMIC); else ectx.ws = NULL; diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 6afcc33ff846..3d41eddc7908 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -6872,7 +6872,7 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, struct dc_stream_update stream_update; } *bundle; - bundle = kzalloc(sizeof(*bundle), GFP_KERNEL); + bundle = kzalloc(sizeof(*bundle), GFP_ATOMIC); if (!bundle) { dm_error("Failed to allocate update bundle\n"); diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c index 942ceb0f6383..f9a58509efb2 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c @@ -1475,8 +1475,10 @@ bool dc_post_update_surfaces_to_stream(struct dc *dc) struct dc_state *dc_create_state(struct dc *dc) { + /* No you really cant allocate random crap here this late in + * atomic_commit_tail. */ struct dc_state *context = kvzalloc(sizeof(struct dc_state), - GFP_KERNEL); + GFP_ATOMIC); if (!context) return NULL; From patchwork Tue Jul 7 20:12:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650057 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 73B1F14DD for ; 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Tue, 07 Jul 2020 13:13:06 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q7sm2515262wra.56.2020.07.07.13.13.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 13:13:06 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 21/25] drm/amdgpu/dc: Stop dma_resv_lock inversion in commit_tail Date: Tue, 7 Jul 2020 22:12:25 +0200 Message-Id: <20200707201229.472834-22-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Trying to grab dma_resv_lock while in commit_tail before we've done all the code that leads to the eventual signalling of the vblank event (which can be a dma_fence) is deadlock-y. Don't do that. Here the solution is easy because just grabbing locks to read something races anyway. We don't need to bother, READ_ONCE is equivalent. And avoids the locking issue. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 3d41eddc7908..d6bb876a74e5 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -6949,7 +6949,11 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, * explicitly on fences instead * and in general should be called for * blocking commit to as per framework helpers + * + * Yes, this deadlocks, since you're calling dma_resv_lock in a + * path that leads to a dma_fence_signal(). Don't do that. */ +#if 0 r = amdgpu_bo_reserve(abo, true); if (unlikely(r != 0)) DRM_ERROR("failed to reserve buffer before flip\n"); @@ -6959,6 +6963,12 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, tmz_surface = amdgpu_bo_encrypted(abo); amdgpu_bo_unreserve(abo); +#endif + /* + * this races anyway, so READ_ONCE isn't any better or worse + * than the stuff above. Except the stuff above can deadlock. + */ + tiling_flags = READ_ONCE(abo->tiling_flags); fill_dc_plane_info_and_addr( dm->adev, new_plane_state, tiling_flags, From patchwork Tue Jul 7 20:12:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650061 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 53CB792A for ; Tue, 7 Jul 2020 20:13:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BFC42075B for ; Tue, 7 Jul 2020 20:13:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="h/9rvaxm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728730AbgGGUNK (ORCPT ); Tue, 7 Jul 2020 16:13:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728737AbgGGUNJ (ORCPT ); Tue, 7 Jul 2020 16:13:09 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B9FBC08C5DC for ; Tue, 7 Jul 2020 13:13:09 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id q15so469130wmj.2 for ; Tue, 07 Jul 2020 13:13:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=J/s3MmMboTlzjq+8NZ+kuHYErla2b65vDUsaQSqJLtQ=; b=h/9rvaxmqOgZnk0yzbidQ1mSiN2f8H+tTzjFdhGdFOWlNwkDo4JJi3I20FJiVQ64++ 9VJT4q9VDm5n5KWBq+/qF0XamCRdfGRwp7BYVYCjbzT/qAAc5KAW0TvQWvcGnmu5uO6S M3uCxlfFkcBpdt/fJ0q8qkf07KDjc8MnphevQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=J/s3MmMboTlzjq+8NZ+kuHYErla2b65vDUsaQSqJLtQ=; b=okOjO2vJK/kQ0su1+etnyZvaiZBUww+xW4w4N20LKfTR4d70fjzcVMLAXQRP1z1C7H cZMmq6nkCj+BLJEFPjEomeTl7RtxxpYUAH6MRj7x9ULo0nd9FmHbDsdLXPKVjRct/J5X H1ImwMj8DT2gOsH2oVTX/1YDIHF4y1QaN6LK46PWNA6tFyM5WRr/MyyRNGVkG3LehHIG BPkb8RiyX1sBc2hjHbwS1r7VwgHGMxSIOYyJR28t0qnlt9MJfSrT46nBspomQaiA5+GA Xt31lLy590oJghVWzy+uEJr647f0sxryPcaiXKmAT6b5rDqL2aH03Ip9XgvDHfnOk440 +gCg== X-Gm-Message-State: AOAM530wi0WQIt9UYzWbYYtEFUYDKSDLGSGXaxeOzo0XUE5HRn836Iy4 /q9jh65ZZtU4ntmfAKq+jrcrwg== X-Google-Smtp-Source: ABdhPJxlP5xpy/2lURkIV3PTnLCHYkUbyRh4w5Xrsscd+z01BMadEva1i1SCumwZqijjHCScWIcFig== X-Received: by 2002:a1c:96c5:: with SMTP id y188mr6024472wmd.71.1594152788077; Tue, 07 Jul 2020 13:13:08 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q7sm2515262wra.56.2020.07.07.13.13.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 13:13:07 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 22/25] drm/scheduler: use dma-fence annotations in tdr work Date: Tue, 7 Jul 2020 22:12:26 +0200 Message-Id: <20200707201229.472834-23-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org In the face of unpriviledged userspace being able to submit bogus gpu workloads the kernel needs gpu timeout and reset (tdr) to guarantee that dma_fences actually complete. Annotate this worker to make sure we don't have any accidental locking inversions or other problems lurking. Originally this was part of the overall scheduler annotation patch. But amdgpu has some glorious inversions here: - grabs console_lock - does a full modeset, which grabs all kinds of locks (drm_modeset_lock, dma_resv_lock) which can deadlock with dma_fence_wait held inside them. - almost minor at that point, but the modeset code also allocates memory These all look like they'll be very hard to fix properly, the hardware seems to require a full display reset with any gpu recovery. Hence split out as a seperate patch. Since amdgpu isn't the only hardware driver that needs to reset the display (at least gen2/3 on intel have the same problem) we need a generic solution for this. There's two tricks we could still from drm/i915 and lift to dma-fence: - The big whack, aka force-complete all fences. i915 does this for all pending jobs if the reset is somehow stuck. Trouble is we'd need to do this for all fences in the entire system, and just the book-keeping for that will be fun. Plus lots of drivers use fences for all kinds of internal stuff like memory management, so unconditionally resetting all of them doesn't work. I'm also hoping that with these fence annotations we could enlist lockdep in finding the last offenders causing deadlocks, and we could remove this get-out-of-jail trick. - The more feasible approach (across drivers at least as part of the dma_fence contract) is what drm/i915 does for gen2/3: When we need to reset the display we wake up all dma_fence_wait_interruptible calls, or well at least the equivalent of those in i915 internally. Relying on ioctl restart we force all other threads to release their locks, which means the tdr thread is guaranteed to be able to get them. I think we could implement this at the dma_fence level, including proper lockdep annotations. dma_fence_begin_tdr(): - must be nested within a dma_fence_begin/end_signalling section - will wake up all interruptible (but not the non-interruptible) dma_fence_wait() calls and force them to complete with a -ERESTARTSYS errno code. All new interrupitble calls to dma_fence_wait() will immeidately fail with the same error code. dma_fence_end_trdr(): - this will convert dma_fence_wait() calls back to normal. Of course interrupting dma_fence_wait is only ok if the caller specified that, which means we need to split the annotations into interruptible and non-interruptible version. If we then make sure that we only use interruptible dma_fence_wait() calls while holding drm_modeset_lock we can grab them in tdr code, and allow display resets. Doing the same for dma_resv_lock might be a lot harder, so buffer updates must be avoided. What's worse, we're not going to be able to make the dma_fence_wait calls in mmu-notifiers interruptible, that doesn't work. So allocating memory still wont' be allowed, even in tdr sections. Plus obviously we can use this trick only in tdr, it is rather intrusive. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/scheduler/sched_main.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 52f1ab4bc922..a1c091e11ffd 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -281,9 +281,12 @@ static void drm_sched_job_timedout(struct work_struct *work) { struct drm_gpu_scheduler *sched; struct drm_sched_job *job; + bool fence_cookie; sched = container_of(work, struct drm_gpu_scheduler, work_tdr.work); + fence_cookie = dma_fence_begin_signalling(); + /* Protects against concurrent deletion in drm_sched_get_cleanup_job */ spin_lock(&sched->job_list_lock); job = list_first_entry_or_null(&sched->ring_mirror_list, @@ -315,6 +318,8 @@ static void drm_sched_job_timedout(struct work_struct *work) spin_lock(&sched->job_list_lock); drm_sched_start_timeout(sched); spin_unlock(&sched->job_list_lock); + + dma_fence_end_signalling(fence_cookie); } /** From patchwork Tue Jul 7 20:12:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650063 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 08BC514E3 for ; Tue, 7 Jul 2020 20:13:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4B00207DF for ; Tue, 7 Jul 2020 20:13:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="jCpkXGY5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728757AbgGGUNM (ORCPT ); Tue, 7 Jul 2020 16:13:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728737AbgGGUNK (ORCPT ); Tue, 7 Jul 2020 16:13:10 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 916A8C061755 for ; Tue, 7 Jul 2020 13:13:10 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id g10so2449268wmc.1 for ; Tue, 07 Jul 2020 13:13:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rXr2As7rh2rrJJ3ahJynDuHkNm4sNZ1+ixU/+yJ6OOk=; b=jCpkXGY5p769RIVb0rIEa9p0h9fBKQNebf/um2oaUcGoDwZigWKpNG4nfukkQHidFs E6lxceTU0TuvUe5FAj8xthM3oTWkjYklv3mDELPUV67jWfa1JuhnpuIRVXm8+h5SzPfO Ufhwy9N9nss079z/+kJ7Mrbm2U0wuBymlNZVs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rXr2As7rh2rrJJ3ahJynDuHkNm4sNZ1+ixU/+yJ6OOk=; b=gzs+NuhFW4x4q58GF5G9Bck9ozG4FTCaZFx/znhEq6+i8dl+YiFYBe23z5esY7EO9B 3avSXokssofSgP1LJLJ6o+Gl444crA9+1suna0uMcyY2hHe1CgKY8DWiQ9qQGNbkzYql xwA24Udr0EjgY9RBdCTnpZFdgbsmytTjANUob4wj/LVrp5WpMtNPqDSsBOIo9XLjuCsa 8P1vyJtvW+vl/EqRU0FHf11ncLtyyDTMxK7hwaY0PRRRknjJ/+64j40pAlVZrHwCqBZc Q4wCWD217DvQlHW9O4c1nyb1jC+XnKPO9097Fju2AgaSRdRK73HF2u8S5mbOvyNcCvBq ILnA== X-Gm-Message-State: AOAM530Z9GOAy/QayeMOP297XqDHzd4Z/RC4VVfwOndZhUcLQfyhHO1D sFRIWKcS18ZNvUzynNW4zep6dw== X-Google-Smtp-Source: ABdhPJw0HizUzWXc4vdabJmS3Cgp6vG06A9p7AbsD/W0R1T8bAZ0kiaRqVn6YrSTgdWX5nrJ4Acaug== X-Received: by 2002:a7b:c394:: with SMTP id s20mr6139458wmj.31.1594152789350; Tue, 07 Jul 2020 13:13:09 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q7sm2515262wra.56.2020.07.07.13.13.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 13:13:08 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= Subject: [PATCH 23/25] drm/amdgpu: use dma-fence annotations for gpu reset code Date: Tue, 7 Jul 2020 22:12:27 +0200 Message-Id: <20200707201229.472834-24-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org To improve coverage also annotate the gpu reset code itself, since that's called from other places than drm/scheduler (which is already annotated). Annotations nests, so this doesn't break anything, and allows easier testing. Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index a649e40fd96f..3a3bccd7f1c7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -4261,6 +4261,9 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, (amdgpu_asic_reset_method(adev) == AMD_RESET_METHOD_BACO) ? true : false; bool audio_suspended = false; + bool fence_cookie; + + fence_cookie = dma_fence_begin_signalling(); /* * Flush RAM to disk so that after reboot @@ -4289,6 +4292,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, DRM_INFO("Bailing on TDR for s_job:%llx, hive: %llx as another already in progress", job ? job->base.id : -1, hive->hive_id); mutex_unlock(&hive->hive_lock); + dma_fence_end_signalling(fence_cookie); return 0; } @@ -4299,8 +4303,10 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, */ INIT_LIST_HEAD(&device_list); if (adev->gmc.xgmi.num_physical_nodes > 1) { - if (!hive) + if (!hive) { + dma_fence_end_signalling(fence_cookie); return -ENODEV; + } if (!list_is_first(&adev->gmc.xgmi.head, &hive->device_list)) list_rotate_to_front(&adev->gmc.xgmi.head, &hive->device_list); device_list_handle = &hive->device_list; @@ -4315,6 +4321,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, DRM_INFO("Bailing on TDR for s_job:%llx, as another already in progress", job ? job->base.id : -1); mutex_unlock(&hive->hive_lock); + dma_fence_end_signalling(fence_cookie); return 0; } @@ -4455,6 +4462,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, if (r) dev_info(adev->dev, "GPU reset end with ret = %d\n", r); + dma_fence_end_signalling(fence_cookie); return r; } From patchwork Tue Jul 7 20:12:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650071 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8181214E3 for ; Tue, 7 Jul 2020 20:13:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6361E20720 for ; Tue, 7 Jul 2020 20:13:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="bJf1I1L+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728760AbgGGUNO (ORCPT ); Tue, 7 Jul 2020 16:13:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49636 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728737AbgGGUNN (ORCPT ); Tue, 7 Jul 2020 16:13:13 -0400 Received: from mail-wm1-x343.google.com (mail-wm1-x343.google.com [IPv6:2a00:1450:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D41A3C08C5E2 for ; Tue, 7 Jul 2020 13:13:11 -0700 (PDT) Received: by mail-wm1-x343.google.com with SMTP id l2so482123wmf.0 for ; Tue, 07 Jul 2020 13:13:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Bx4rDZogC1BiesvVAl0csmMxLWG9gJRV/a92JN7vGQM=; b=bJf1I1L+LMb4JywkuIwVxGfbgP0t0pwYIMyTShYBIQx9CqaCxuzQtn66oYI7dwJ8UY ReIprZw5a1E66OdmMyyL1kbAVVVcl9iPnFMie6takpZaW8GSR98l+rPH48fyiB1Mnb7v IW2XbZ0mCKuiQuhba0ryUsrarW6spkUBB55Ns= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Bx4rDZogC1BiesvVAl0csmMxLWG9gJRV/a92JN7vGQM=; b=N3kwodoEj9HpZ+Yt6H/RvA3ZrZ0bbF8FqjpeOnVXr56CAza/YxwSWkGkmDdPnZn5JZ U2hH90aajS9YyM+RzDF1lvntEpOSHniKs0wXLUibAYmC4alH1gxWUdMfhuhrIlaVsUnB mJVM0ZdD9p3Uk2h60A+34R0PlBI0ps+Gqo8+HdnjjnjxjVTjCNNKdiJt+WRd+KoJChm0 Amp461rQvmSuA+ZupqATjDM7jbEBqaJpETHBAcW6sKOifZkSALN39WXx7pS2jbVldQaR Q1z/sfLeH6uD2ellxEEmVngmZsqLmGD6p33RGRnaVeHRPyosEdidLGcxwTgESc64m4KW EFMg== X-Gm-Message-State: AOAM5322NN9vg9xe3Qg0Mg2GFUjv3byYTyqbtgS1g7B7lILgB/XCASgD IR8BnnwekFROV/0AE88UZSiUMg== X-Google-Smtp-Source: ABdhPJwXeAlwXkHmWCQYSxqV/QPdl+NS9hGpqzKkknV5bjYv2G6QyVcB1RCa1CWqqOsalvaX9zh2MQ== X-Received: by 2002:a1c:1bc6:: with SMTP id b189mr5583866wmb.166.1594152790509; Tue, 07 Jul 2020 13:13:10 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id q7sm2515262wra.56.2020.07.07.13.13.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 13:13:09 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 24/25] Revert "drm/amdgpu: add fbdev suspend/resume on gpu reset" Date: Tue, 7 Jul 2020 22:12:28 +0200 Message-Id: <20200707201229.472834-25-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This is one from the department of "maybe play lottery if you hit this, karma compensation might work". Or at least lockdep ftw! This reverts commit 565d1941557756a584ac357d945bc374d5fcd1d0. It's not quite as low-risk as the commit message claims, because this grabs console_lock, which might be held when we allocate memory, which might never happen because the dma_fence_wait() is stuck waiting on our gpu reset: [ 136.763714] ====================================================== [ 136.763714] WARNING: possible circular locking dependency detected [ 136.763715] 5.7.0-rc3+ #346 Tainted: G W [ 136.763716] ------------------------------------------------------ [ 136.763716] kworker/2:3/682 is trying to acquire lock: [ 136.763716] ffffffff8226f140 (console_lock){+.+.}-{0:0}, at: drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763723] but task is already holding lock: [ 136.763724] ffffffff82318c80 (dma_fence_map){++++}-{0:0}, at: drm_sched_job_timedout+0x25/0xf0 [gpu_sched] [ 136.763726] which lock already depends on the new lock. [ 136.763726] the existing dependency chain (in reverse order) is: [ 136.763727] -> #2 (dma_fence_map){++++}-{0:0}: [ 136.763730] __dma_fence_might_wait+0x41/0xb0 [ 136.763732] dma_resv_lockdep+0x171/0x202 [ 136.763734] do_one_initcall+0x5d/0x2f0 [ 136.763736] kernel_init_freeable+0x20d/0x26d [ 136.763738] kernel_init+0xa/0xfb [ 136.763740] ret_from_fork+0x27/0x50 [ 136.763740] -> #1 (fs_reclaim){+.+.}-{0:0}: [ 136.763743] fs_reclaim_acquire.part.0+0x25/0x30 [ 136.763745] kmem_cache_alloc_trace+0x2e/0x6e0 [ 136.763747] device_create_groups_vargs+0x52/0xf0 [ 136.763747] device_create+0x49/0x60 [ 136.763749] fb_console_init+0x25/0x145 [ 136.763750] fbmem_init+0xcc/0xe2 [ 136.763750] do_one_initcall+0x5d/0x2f0 [ 136.763751] kernel_init_freeable+0x20d/0x26d [ 136.763752] kernel_init+0xa/0xfb [ 136.763753] ret_from_fork+0x27/0x50 [ 136.763753] -> #0 (console_lock){+.+.}-{0:0}: [ 136.763755] __lock_acquire+0x1241/0x23f0 [ 136.763756] lock_acquire+0xad/0x370 [ 136.763757] console_lock+0x47/0x70 [ 136.763761] drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763809] amdgpu_device_gpu_recover.cold+0x21e/0xe7b [amdgpu] [ 136.763850] amdgpu_job_timedout+0xfb/0x150 [amdgpu] [ 136.763851] drm_sched_job_timedout+0x8a/0xf0 [gpu_sched] [ 136.763852] process_one_work+0x23c/0x580 [ 136.763853] worker_thread+0x50/0x3b0 [ 136.763854] kthread+0x12e/0x150 [ 136.763855] ret_from_fork+0x27/0x50 [ 136.763855] other info that might help us debug this: [ 136.763856] Chain exists of: console_lock --> fs_reclaim --> dma_fence_map [ 136.763857] Possible unsafe locking scenario: [ 136.763857] CPU0 CPU1 [ 136.763857] ---- ---- [ 136.763857] lock(dma_fence_map); [ 136.763858] lock(fs_reclaim); [ 136.763858] lock(dma_fence_map); [ 136.763858] lock(console_lock); [ 136.763859] *** DEADLOCK *** [ 136.763860] 4 locks held by kworker/2:3/682: [ 136.763860] #0: ffff8887fb81c938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1bc/0x580 [ 136.763862] #1: ffffc90000cafe58 ((work_completion)(&(&sched->work_tdr)->work)){+.+.}-{0:0}, at: process_one_work+0x1bc/0x580 [ 136.763863] #2: ffffffff82318c80 (dma_fence_map){++++}-{0:0}, at: drm_sched_job_timedout+0x25/0xf0 [gpu_sched] [ 136.763865] #3: ffff8887ab621748 (&adev->lock_reset){+.+.}-{3:3}, at: amdgpu_device_gpu_recover.cold+0x5ab/0xe7b [amdgpu] [ 136.763914] stack backtrace: [ 136.763915] CPU: 2 PID: 682 Comm: kworker/2:3 Tainted: G W 5.7.0-rc3+ #346 [ 136.763916] Hardware name: System manufacturer System Product Name/PRIME X370-PRO, BIOS 4011 04/19/2018 [ 136.763918] Workqueue: events drm_sched_job_timedout [gpu_sched] [ 136.763919] Call Trace: [ 136.763922] dump_stack+0x8f/0xd0 [ 136.763924] check_noncircular+0x162/0x180 [ 136.763926] __lock_acquire+0x1241/0x23f0 [ 136.763927] lock_acquire+0xad/0x370 [ 136.763932] ? drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763933] ? mark_held_locks+0x2d/0x80 [ 136.763934] ? _raw_spin_unlock_irqrestore+0x46/0x60 [ 136.763936] console_lock+0x47/0x70 [ 136.763940] ? drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763944] drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763993] amdgpu_device_gpu_recover.cold+0x21e/0xe7b [amdgpu] [ 136.764036] amdgpu_job_timedout+0xfb/0x150 [amdgpu] [ 136.764038] drm_sched_job_timedout+0x8a/0xf0 [gpu_sched] [ 136.764040] process_one_work+0x23c/0x580 [ 136.764041] worker_thread+0x50/0x3b0 [ 136.764042] ? process_one_work+0x580/0x580 [ 136.764044] kthread+0x12e/0x150 [ 136.764045] ? kthread_create_worker_on_cpu+0x70/0x70 [ 136.764046] ret_from_fork+0x27/0x50 Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 3a3bccd7f1c7..44b321eecc3d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -4109,8 +4109,6 @@ static int amdgpu_do_asic_reset(struct amdgpu_hive_info *hive, if (r) goto out; - amdgpu_fbdev_set_suspend(tmp_adev, 0); - /* must succeed. */ amdgpu_ras_resume(tmp_adev); @@ -4351,8 +4349,6 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, */ amdgpu_unregister_gpu_instance(tmp_adev); - amdgpu_fbdev_set_suspend(tmp_adev, 1); - /* disable ras on ALL IPs */ if (!(in_ras_intr && !use_baco) && amdgpu_device_ip_need_full_reset(tmp_adev)) From patchwork Tue Jul 7 20:12:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11650073 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 109C292A for ; Tue, 7 Jul 2020 20:13:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8C1E207F9 for ; Tue, 7 Jul 2020 20:13:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="jIDMowCU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728767AbgGGUNO (ORCPT ); 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Tue, 07 Jul 2020 13:13:11 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , linux-rdma@vger.kernel.org, Daniel Vetter , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, Chris Wilson , Maarten Lankhorst , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Daniel Vetter Subject: [PATCH 25/25] drm/amdgpu: gpu recovery does full modesets Date: Tue, 7 Jul 2020 22:12:29 +0200 Message-Id: <20200707201229.472834-26-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-1-daniel.vetter@ffwll.ch> References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org ... I think it's time to stop this little exercise. The lockdep splat, for the record: [ 132.583381] ====================================================== [ 132.584091] WARNING: possible circular locking dependency detected [ 132.584775] 5.7.0-rc3+ #346 Tainted: G W [ 132.585461] ------------------------------------------------------ [ 132.586184] kworker/2:3/865 is trying to acquire lock: [ 132.586857] ffffc90000677c70 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_atomic_helper_suspend+0x38/0x120 [drm_kms_helper] [ 132.587569] but task is already holding lock: [ 132.589044] ffffffff82318c80 (dma_fence_map){++++}-{0:0}, at: drm_sched_job_timedout+0x25/0xf0 [gpu_sched] [ 132.589803] which lock already depends on the new lock. [ 132.592009] the existing dependency chain (in reverse order) is: [ 132.593507] -> #2 (dma_fence_map){++++}-{0:0}: [ 132.595019] dma_fence_begin_signalling+0x50/0x60 [ 132.595767] drm_atomic_helper_commit+0xa1/0x180 [drm_kms_helper] [ 132.596567] drm_client_modeset_commit_atomic+0x1ea/0x250 [drm] [ 132.597420] drm_client_modeset_commit_locked+0x55/0x190 [drm] [ 132.598178] drm_client_modeset_commit+0x24/0x40 [drm] [ 132.598948] drm_fb_helper_restore_fbdev_mode_unlocked+0x4b/0xa0 [drm_kms_helper] [ 132.599738] drm_fb_helper_set_par+0x30/0x40 [drm_kms_helper] [ 132.600539] fbcon_init+0x2e8/0x660 [ 132.601344] visual_init+0xce/0x130 [ 132.602156] do_bind_con_driver+0x1bc/0x2b0 [ 132.602970] do_take_over_console+0x115/0x180 [ 132.603763] do_fbcon_takeover+0x58/0xb0 [ 132.604564] register_framebuffer+0x1ee/0x300 [ 132.605369] __drm_fb_helper_initial_config_and_unlock+0x36e/0x520 [drm_kms_helper] [ 132.606187] amdgpu_fbdev_init+0xb3/0xf0 [amdgpu] [ 132.607032] amdgpu_device_init.cold+0xe90/0x1677 [amdgpu] [ 132.607862] amdgpu_driver_load_kms+0x5a/0x200 [amdgpu] [ 132.608697] amdgpu_pci_probe+0xf7/0x180 [amdgpu] [ 132.609511] local_pci_probe+0x42/0x80 [ 132.610324] pci_device_probe+0x104/0x1a0 [ 132.611130] really_probe+0x147/0x3c0 [ 132.611939] driver_probe_device+0xb6/0x100 [ 132.612766] device_driver_attach+0x53/0x60 [ 132.613593] __driver_attach+0x8c/0x150 [ 132.614419] bus_for_each_dev+0x7b/0xc0 [ 132.615249] bus_add_driver+0x14c/0x1f0 [ 132.616071] driver_register+0x6c/0xc0 [ 132.616902] do_one_initcall+0x5d/0x2f0 [ 132.617731] do_init_module+0x5c/0x230 [ 132.618560] load_module+0x2981/0x2bc0 [ 132.619391] __do_sys_finit_module+0xaa/0x110 [ 132.620228] do_syscall_64+0x5a/0x250 [ 132.621064] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 132.621903] -> #1 (crtc_ww_class_mutex){+.+.}-{3:3}: [ 132.623587] __ww_mutex_lock.constprop.0+0xcc/0x10c0 [ 132.624448] ww_mutex_lock+0x43/0xb0 [ 132.625315] drm_modeset_lock+0x44/0x120 [drm] [ 132.626184] drmm_mode_config_init+0x2db/0x8b0 [drm] [ 132.627098] amdgpu_device_init.cold+0xbd1/0x1677 [amdgpu] [ 132.628007] amdgpu_driver_load_kms+0x5a/0x200 [amdgpu] [ 132.628920] amdgpu_pci_probe+0xf7/0x180 [amdgpu] [ 132.629804] local_pci_probe+0x42/0x80 [ 132.630690] pci_device_probe+0x104/0x1a0 [ 132.631583] really_probe+0x147/0x3c0 [ 132.632479] driver_probe_device+0xb6/0x100 [ 132.633379] device_driver_attach+0x53/0x60 [ 132.634275] __driver_attach+0x8c/0x150 [ 132.635170] bus_for_each_dev+0x7b/0xc0 [ 132.636069] bus_add_driver+0x14c/0x1f0 [ 132.636974] driver_register+0x6c/0xc0 [ 132.637870] do_one_initcall+0x5d/0x2f0 [ 132.638765] do_init_module+0x5c/0x230 [ 132.639654] load_module+0x2981/0x2bc0 [ 132.640522] __do_sys_finit_module+0xaa/0x110 [ 132.641372] do_syscall_64+0x5a/0x250 [ 132.642203] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 132.643022] -> #0 (crtc_ww_class_acquire){+.+.}-{0:0}: [ 132.644643] __lock_acquire+0x1241/0x23f0 [ 132.645469] lock_acquire+0xad/0x370 [ 132.646274] drm_modeset_acquire_init+0xd2/0x100 [drm] [ 132.647071] drm_atomic_helper_suspend+0x38/0x120 [drm_kms_helper] [ 132.647902] dm_suspend+0x1c/0x60 [amdgpu] [ 132.648698] amdgpu_device_ip_suspend_phase1+0x83/0xe0 [amdgpu] [ 132.649498] amdgpu_device_ip_suspend+0x1c/0x60 [amdgpu] [ 132.650300] amdgpu_device_gpu_recover.cold+0x4e6/0xe64 [amdgpu] [ 132.651084] amdgpu_job_timedout+0xfb/0x150 [amdgpu] [ 132.651825] drm_sched_job_timedout+0x8a/0xf0 [gpu_sched] [ 132.652594] process_one_work+0x23c/0x580 [ 132.653402] worker_thread+0x50/0x3b0 [ 132.654139] kthread+0x12e/0x150 [ 132.654868] ret_from_fork+0x27/0x50 [ 132.655598] other info that might help us debug this: [ 132.657739] Chain exists of: crtc_ww_class_acquire --> crtc_ww_class_mutex --> dma_fence_map [ 132.659877] Possible unsafe locking scenario: [ 132.661416] CPU0 CPU1 [ 132.662126] ---- ---- [ 132.662847] lock(dma_fence_map); [ 132.663574] lock(crtc_ww_class_mutex); [ 132.664319] lock(dma_fence_map); [ 132.665063] lock(crtc_ww_class_acquire); [ 132.665799] *** DEADLOCK *** [ 132.667965] 4 locks held by kworker/2:3/865: [ 132.668701] #0: ffff8887fb81c938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1bc/0x580 [ 132.669462] #1: ffffc90000677e58 ((work_completion)(&(&sched->work_tdr)->work)){+.+.}-{0:0}, at: process_one_work+0x1bc/0x580 [ 132.670242] #2: ffffffff82318c80 (dma_fence_map){++++}-{0:0}, at: drm_sched_job_timedout+0x25/0xf0 [gpu_sched] [ 132.671039] #3: ffff8887b84a1748 (&adev->lock_reset){+.+.}-{3:3}, at: amdgpu_device_gpu_recover.cold+0x59e/0xe64 [amdgpu] [ 132.671902] stack backtrace: [ 132.673515] CPU: 2 PID: 865 Comm: kworker/2:3 Tainted: G W 5.7.0-rc3+ #346 [ 132.674347] Hardware name: System manufacturer System Product Name/PRIME X370-PRO, BIOS 4011 04/19/2018 [ 132.675194] Workqueue: events drm_sched_job_timedout [gpu_sched] [ 132.676046] Call Trace: [ 132.676897] dump_stack+0x8f/0xd0 [ 132.677748] check_noncircular+0x162/0x180 [ 132.678604] ? stack_trace_save+0x4b/0x70 [ 132.679459] __lock_acquire+0x1241/0x23f0 [ 132.680311] lock_acquire+0xad/0x370 [ 132.681163] ? drm_atomic_helper_suspend+0x38/0x120 [drm_kms_helper] [ 132.682021] ? cpumask_next+0x16/0x20 [ 132.682880] ? module_assert_mutex_or_preempt+0x14/0x40 [ 132.683737] ? __module_address+0x28/0xf0 [ 132.684601] drm_modeset_acquire_init+0xd2/0x100 [drm] [ 132.685466] ? drm_atomic_helper_suspend+0x38/0x120 [drm_kms_helper] [ 132.686335] drm_atomic_helper_suspend+0x38/0x120 [drm_kms_helper] [ 132.687255] dm_suspend+0x1c/0x60 [amdgpu] [ 132.688152] amdgpu_device_ip_suspend_phase1+0x83/0xe0 [amdgpu] [ 132.689057] ? amdgpu_fence_process+0x4c/0x150 [amdgpu] [ 132.689963] amdgpu_device_ip_suspend+0x1c/0x60 [amdgpu] [ 132.690893] amdgpu_device_gpu_recover.cold+0x4e6/0xe64 [amdgpu] [ 132.691818] amdgpu_job_timedout+0xfb/0x150 [amdgpu] [ 132.692707] drm_sched_job_timedout+0x8a/0xf0 [gpu_sched] [ 132.693597] process_one_work+0x23c/0x580 [ 132.694487] worker_thread+0x50/0x3b0 [ 132.695373] ? process_one_work+0x580/0x580 [ 132.696264] kthread+0x12e/0x150 [ 132.697154] ? kthread_create_worker_on_cpu+0x70/0x70 [ 132.698057] ret_from_fork+0x27/0x50 Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-rdma@vger.kernel.org Cc: amd-gfx@lists.freedesktop.org Cc: intel-gfx@lists.freedesktop.org Cc: Chris Wilson Cc: Maarten Lankhorst Cc: Christian König Signed-off-by: Daniel Vetter --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 44b321eecc3d..910c86f577b2 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -2477,6 +2477,14 @@ static int amdgpu_device_ip_suspend_phase1(struct amdgpu_device *adev) /* displays are handled separately */ if (adev->ip_blocks[i].version->type == AMD_IP_BLOCK_TYPE_DCE) { /* XXX handle errors */ + + /* + * This is dm_suspend, which calls modeset locks, and + * that a pretty good inversion against dma_fence_signal + * which gpu recovery is supposed to guarantee. + * + * Dont ask me how to fix this. + */ r = adev->ip_blocks[i].version->funcs->suspend(adev); /* XXX handle errors */ if (r) {