From: Chris Wilson <chris@chris-wilson.co.uk> To: intel-gfx@lists.freedesktop.org Cc: Chris Wilson <chris@chris-wilson.co.uk>, Tvrtko Ursulin <tvrtko.ursulin@intel.com>, stable@vger.kernel.org Subject: [PATCH 1/4] drm/i915/gt: Do not schedule normal requests immediately along virtual Date: Mon, 25 May 2020 21:28:58 +0100 [thread overview] Message-ID: <20200525202901.32244-1-chris@chris-wilson.co.uk> (raw) When we push a virtual request onto the HW, we update the rq->engine to point to the physical engine. A request that is then submitted by the user that waits upon the virtual engine, but along the physical engine in use, will then see that it is due to be submitted to the same engine and take a shortcut (and be queued without waiting for the completion fence). However, the virtual request may be preempted (either by higher priority users, or by timeslicing) and removed from the physical engine to be migrated over to one of its siblings. The dependent normal request however is oblivious to the removal of the virtual request and remains queued to execute on HW, believing that once it reaches the head of its queue all of its predecessors will have completed executing! Fixes: 6d06779e8672 ("drm/i915: Load balancing across a virtual engine") Testcase: igt/gem_exec_balancer/sliced Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: <stable@vger.kernel.org> # v5.3+ --- drivers/gpu/drm/i915/i915_request.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index c282719ad3ac..51588209bddd 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1074,7 +1074,7 @@ i915_request_await_request(struct i915_request *to, struct i915_request *from) return ret; } - if (to->engine == from->engine) + if (is_power_of_2(to->execution_mask | READ_ONCE(from->execution_mask))) ret = i915_sw_fence_await_sw_fence_gfp(&to->submit, &from->submit, I915_FENCE_GFP); -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Chris Wilson <chris@chris-wilson.co.uk> To: intel-gfx@lists.freedesktop.org Cc: stable@vger.kernel.org, Chris Wilson <chris@chris-wilson.co.uk> Subject: [Intel-gfx] [PATCH 1/4] drm/i915/gt: Do not schedule normal requests immediately along virtual Date: Mon, 25 May 2020 21:28:58 +0100 [thread overview] Message-ID: <20200525202901.32244-1-chris@chris-wilson.co.uk> (raw) When we push a virtual request onto the HW, we update the rq->engine to point to the physical engine. A request that is then submitted by the user that waits upon the virtual engine, but along the physical engine in use, will then see that it is due to be submitted to the same engine and take a shortcut (and be queued without waiting for the completion fence). However, the virtual request may be preempted (either by higher priority users, or by timeslicing) and removed from the physical engine to be migrated over to one of its siblings. The dependent normal request however is oblivious to the removal of the virtual request and remains queued to execute on HW, believing that once it reaches the head of its queue all of its predecessors will have completed executing! Fixes: 6d06779e8672 ("drm/i915: Load balancing across a virtual engine") Testcase: igt/gem_exec_balancer/sliced Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: <stable@vger.kernel.org> # v5.3+ --- drivers/gpu/drm/i915/i915_request.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index c282719ad3ac..51588209bddd 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1074,7 +1074,7 @@ i915_request_await_request(struct i915_request *to, struct i915_request *from) return ret; } - if (to->engine == from->engine) + if (is_power_of_2(to->execution_mask | READ_ONCE(from->execution_mask))) ret = i915_sw_fence_await_sw_fence_gfp(&to->submit, &from->submit, I915_FENCE_GFP); -- 2.20.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next reply other threads:[~2020-05-25 20:29 UTC|newest] Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-25 20:28 Chris Wilson [this message] 2020-05-25 20:28 ` [Intel-gfx] [PATCH 1/4] drm/i915/gt: Do not schedule normal requests immediately along virtual Chris Wilson 2020-05-25 20:28 ` [Intel-gfx] [PATCH 2/4] drm/i915/gt: Use virtual_engine during execlists_dequeue Chris Wilson 2020-05-25 20:29 ` [Intel-gfx] [PATCH 3/4] drm/i915/gt: Decouple inflight virtual engines Chris Wilson 2020-05-25 20:29 ` [Intel-gfx] [PATCH 4/4] drm/i915/gt: Resubmit the virtual engine on schedule-out Chris Wilson 2020-05-25 21:06 ` [Intel-gfx] ✓ Fi.CI.BAT: success for series starting with [1/4] drm/i915/gt: Do not schedule normal requests immediately along virtual Patchwork 2020-05-25 23:41 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork 2020-05-26 0:23 ` [PATCH 1/4] " Sasha Levin 2020-05-26 0:23 ` [Intel-gfx] " Sasha Levin 2020-05-26 8:29 ` Tvrtko Ursulin 2020-05-26 8:29 ` Tvrtko Ursulin
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