From patchwork Mon May 4 04:49:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11524993 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 0028114C0 for ; Mon, 4 May 2020 04:49:55 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DCECF206C0 for ; Mon, 4 May 2020 04:49:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DCECF206C0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 66F7F6E2F8; Mon, 4 May 2020 04:49:42 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id A2A926E2DF for ; Mon, 4 May 2020 04:49:36 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 21102375-1500050 for multiple; Mon, 04 May 2020 05:49:10 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Mon, 4 May 2020 05:49:00 +0100 Message-Id: <20200504044903.7626-19-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200504044903.7626-1-chris@chris-wilson.co.uk> References: <20200504044903.7626-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 19/22] drm/i915/gem: Separate the ww_mutex walker into its own list X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Chris Wilson Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" In preparation for making eb_vma bigger and heavy to run inn parallel, we need to stop apply an in-place swap() to reorder around ww_mutex deadlocks. Keep the array intact and reorder the locks using a dedicated list. Signed-off-by: Chris Wilson --- .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 48 +++++++++++-------- drivers/gpu/drm/i915/i915_utils.h | 6 +++ 2 files changed, 34 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index 67ba33b3de60..0d773767c2ac 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -36,6 +36,7 @@ struct eb_vma { struct drm_i915_gem_exec_object2 *exec; struct list_head bind_link; struct list_head reloc_link; + struct list_head lock_link; struct hlist_node node; u32 handle; @@ -254,6 +255,8 @@ struct i915_execbuffer { /** list of vma that have execobj.relocation_count */ struct list_head relocs; + struct list_head lock; + /** * Track the most recently used object for relocations, as we * frequently have to perform multiple relocations within the same @@ -399,6 +402,10 @@ static int eb_create(struct i915_execbuffer *eb) eb->lut_size = -eb->buffer_count; } + INIT_LIST_HEAD(&eb->relocs); + INIT_LIST_HEAD(&eb->unbound); + INIT_LIST_HEAD(&eb->lock); + return 0; } @@ -604,6 +611,8 @@ eb_add_vma(struct i915_execbuffer *eb, eb_unreserve_vma(ev); list_add_tail(&ev->bind_link, &eb->unbound); } + + list_add_tail(&ev->lock_link, &eb->lock); } static inline int use_cpu_reloc(const struct reloc_cache *cache, @@ -880,9 +889,6 @@ static int eb_lookup_vmas(struct i915_execbuffer *eb) unsigned int i; int err = 0; - INIT_LIST_HEAD(&eb->relocs); - INIT_LIST_HEAD(&eb->unbound); - for (i = 0; i < eb->buffer_count; i++) { struct i915_vma *vma; @@ -1790,38 +1796,39 @@ static int eb_relocate(struct i915_execbuffer *eb) static int eb_move_to_gpu(struct i915_execbuffer *eb) { - const unsigned int count = eb->buffer_count; struct ww_acquire_ctx acquire; - unsigned int i; + struct eb_vma *ev; int err = 0; ww_acquire_init(&acquire, &reservation_ww_class); - for (i = 0; i < count; i++) { - struct eb_vma *ev = &eb->vma[i]; + list_for_each_entry(ev, &eb->lock, lock_link) { struct i915_vma *vma = ev->vma; err = ww_mutex_lock_interruptible(&vma->resv->lock, &acquire); if (err == -EDEADLK) { - GEM_BUG_ON(i == 0); - do { - int j = i - 1; + struct eb_vma *unlock = ev, *en; - ww_mutex_unlock(&eb->vma[j].vma->resv->lock); - - swap(eb->vma[i], eb->vma[j]); - } while (--i); + list_for_each_entry_safe_continue_reverse(unlock, en, &eb->lock, lock_link) { + ww_mutex_unlock(&unlock->vma->resv->lock); + list_move_tail(&unlock->lock_link, &eb->lock); + } + GEM_BUG_ON(!list_is_first(&ev->lock_link, &eb->lock)); err = ww_mutex_lock_slow_interruptible(&vma->resv->lock, &acquire); } - if (err) - break; + if (err) { + list_for_each_entry_continue_reverse(ev, &eb->lock, lock_link) + ww_mutex_unlock(&ev->vma->resv->lock); + + ww_acquire_fini(&acquire); + goto err_skip; + } } ww_acquire_done(&acquire); - while (i--) { - struct eb_vma *ev = &eb->vma[i]; + list_for_each_entry(ev, &eb->lock, lock_link) { struct i915_vma *vma = ev->vma; unsigned int flags = ev->flags; struct drm_i915_gem_object *obj = vma->obj; @@ -2122,9 +2129,10 @@ static int eb_parse(struct i915_execbuffer *eb) if (err) goto err_trampoline; - eb->vma[eb->buffer_count].vma = i915_vma_get(shadow); - eb->vma[eb->buffer_count].flags = __EXEC_OBJECT_HAS_PIN; eb->batch = &eb->vma[eb->buffer_count++]; + eb->batch->vma = i915_vma_get(shadow); + eb->batch->flags = __EXEC_OBJECT_HAS_PIN; + list_add_tail(&eb->batch->lock_link, &eb->lock); eb->vma[eb->buffer_count].vma = NULL; eb->trampoline = trampoline; diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index 03a73d2bd50d..28813806bc19 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -266,6 +266,12 @@ static inline int list_is_last_rcu(const struct list_head *list, return READ_ONCE(list->next) == head; } +#define list_for_each_entry_safe_continue_reverse(pos, n, head, member) \ + for (pos = list_prev_entry(pos, member), \ + n = list_prev_entry(pos, member); \ + &pos->member != (head); \ + pos = n, n = list_prev_entry(n, member)) + /* * Wait until the work is finally complete, even if it tries to postpone * by requeueing itself. Note, that if the worker never cancels itself,