From patchwork Wed Dec 4 11:26:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11272761 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 8EC1D13B6 for ; Wed, 4 Dec 2019 11:26:53 +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 750AA2077B for ; Wed, 4 Dec 2019 11:26:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 750AA2077B 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 0BFEB6E8C5; Wed, 4 Dec 2019 11:26:53 +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 1FC976E8C5 for ; Wed, 4 Dec 2019 11:26:50 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 19455444-1500050 for multiple; Wed, 04 Dec 2019 11:26:32 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 4 Dec 2019 11:26:33 +0000 Message-Id: <20191204112633.3649206-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v2] drm/i915: Copy across scheduler behaviour flags across submit fences X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" We want the bonded request to have the same scheduler properties as its master so that it is placed at the same depth in the queue. For example, consider we have requests A, B and B', where B & B' are a bonded pair to run in parallel on two engines. A -> B \- B' B will run after A and so may be scheduled on an idle engine and wait on A using a semaphore. B' sees B being executed and so enters the queue on the same engine as A. As B' did not inherit the semaphore-chain from B, it may have higher precedence than A and so preempts execution. However, B' then sits on a semaphore waiting for B, who is waiting for A, who is blocked by B. Ergo B' needs to inherit the scheduler properties from B (i.e. the semaphore chain) so that it is scheduled with the same priority as B and will not be executed ahead of Bs dependencies. Furthermore, to prevent the priorities changing via the expose fence on B', we need to couple in the dependencies for PI. This requires us to relax our sanity-checks that dependencies are strictly in order. Fixes: ee1136908e9b ("drm/i915/execlists: Virtual engine bonding") Testcase: igt/gem_exec_balancer/bonded-chain Testcase: igt/gem_exec_balancer/bonded-semaphore Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin --- Transfer any semaphore dependencies as well. --- drivers/gpu/drm/i915/i915_request.c | 115 ++++++++++++++++++++------ drivers/gpu/drm/i915/i915_scheduler.c | 1 - 2 files changed, 90 insertions(+), 26 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 3109b8a79b9f..e0d24977aa9b 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -300,11 +300,11 @@ void i915_request_retire_upto(struct i915_request *rq) } static int -__i915_request_await_execution(struct i915_request *rq, - struct i915_request *signal, - void (*hook)(struct i915_request *rq, - struct dma_fence *signal), - gfp_t gfp) +__await_execution(struct i915_request *rq, + struct i915_request *signal, + void (*hook)(struct i915_request *rq, + struct dma_fence *signal), + gfp_t gfp) { struct execute_cb *cb; @@ -341,6 +341,8 @@ __i915_request_await_execution(struct i915_request *rq, } spin_unlock_irq(&signal->lock); + /* Copy across semaphore status as we need the same behaviour */ + rq->sched.flags |= signal->sched.flags; return 0; } @@ -824,31 +826,21 @@ already_busywaiting(struct i915_request *rq) } static int -emit_semaphore_wait(struct i915_request *to, - struct i915_request *from, - gfp_t gfp) +__emit_semaphore_wait(struct i915_request *to, + struct i915_request *from, + u32 seqno) { const int has_token = INTEL_GEN(to->i915) >= 12; u32 hwsp_offset; - int len; + int len, err; u32 *cs; GEM_BUG_ON(INTEL_GEN(to->i915) < 8); - /* Just emit the first semaphore we see as request space is limited. */ - if (already_busywaiting(to) & from->engine->mask) - goto await_fence; - - if (i915_request_await_start(to, from) < 0) - goto await_fence; - - /* Only submit our spinner after the signaler is running! */ - if (__i915_request_await_execution(to, from, NULL, gfp)) - goto await_fence; - /* We need to pin the signaler's HWSP until we are finished reading. */ - if (intel_timeline_read_hwsp(from, to, &hwsp_offset)) - goto await_fence; + err = intel_timeline_read_hwsp(from, to, &hwsp_offset); + if (err) + return err; len = 4; if (has_token) @@ -871,7 +863,7 @@ emit_semaphore_wait(struct i915_request *to, MI_SEMAPHORE_POLL | MI_SEMAPHORE_SAD_GTE_SDD) + has_token; - *cs++ = from->fence.seqno; + *cs++ = seqno; *cs++ = hwsp_offset; *cs++ = 0; if (has_token) { @@ -880,6 +872,28 @@ emit_semaphore_wait(struct i915_request *to, } intel_ring_advance(to, cs); + return 0; +} + +static int +emit_semaphore_wait(struct i915_request *to, + struct i915_request *from, + gfp_t gfp) +{ + /* Just emit the first semaphore we see as request space is limited. */ + if (already_busywaiting(to) & from->engine->mask) + goto await_fence; + + if (i915_request_await_start(to, from) < 0) + goto await_fence; + + /* Only submit our spinner after the signaler is running! */ + if (__await_execution(to, from, NULL, gfp)) + goto await_fence; + + if (__emit_semaphore_wait(to, from, from->fence.seqno)) + goto await_fence; + to->sched.semaphores |= from->engine->mask; to->sched.flags |= I915_SCHED_HAS_SEMAPHORE_CHAIN; return 0; @@ -993,6 +1007,58 @@ i915_request_await_dma_fence(struct i915_request *rq, struct dma_fence *fence) return 0; } +static bool intel_timeline_sync_has_start(struct intel_timeline *tl, + struct dma_fence *fence) +{ + return __intel_timeline_sync_is_later(tl, + fence->context, + fence->seqno - 1); +} + +static int intel_timeline_sync_set_start(struct intel_timeline *tl, + const struct dma_fence *fence) +{ + return __intel_timeline_sync_set(tl, fence->context, fence->seqno - 1); +} + +static int +__i915_request_await_execution(struct i915_request *to, + struct i915_request *from, + void (*hook)(struct i915_request *rq, + struct dma_fence *signal)) +{ + bool has_sync; + int err; + + /* Submit both requests at the same time */ + err = __await_execution(to, from, hook, I915_FENCE_GFP); + if (err) + return err; + + if (!to->engine->schedule) + return 0; + + /* Squash repeated depenendices to the same timelines */ + if (intel_timeline_sync_has_start(i915_request_timeline(to), + &from->fence)) + return 0; + + /* Ensure both start together after all semaphores in signal */ + if (from->sched.semaphores && !has_sync) { + err =__emit_semaphore_wait(to, from, from->fence.seqno - 1); + if (err) + return err; + } + + /* Couple the dependency tree for PI on this exposed to->fence */ + err = i915_sched_node_add_dependency(&to->sched, &from->sched); + if (err < 0) + return err; + + return intel_timeline_sync_set_start(i915_request_timeline(to), + &from->fence); +} + int i915_request_await_execution(struct i915_request *rq, struct dma_fence *fence, @@ -1026,8 +1092,7 @@ i915_request_await_execution(struct i915_request *rq, if (dma_fence_is_i915(fence)) ret = __i915_request_await_execution(rq, to_request(fence), - hook, - I915_FENCE_GFP); + hook); else ret = i915_sw_fence_await_dma_fence(&rq->submit, fence, I915_FENCE_TIMEOUT, diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c index ad6ff52bc316..00f5d107f2b7 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.c +++ b/drivers/gpu/drm/i915/i915_scheduler.c @@ -492,7 +492,6 @@ void i915_sched_node_fini(struct i915_sched_node *node) * so we may be called out-of-order. */ list_for_each_entry_safe(dep, tmp, &node->signalers_list, signal_link) { - GEM_BUG_ON(!node_signaled(dep->signaler)); GEM_BUG_ON(!list_empty(&dep->dfs_link)); list_del(&dep->wait_link);