From 56299fb7d9047cc1d25362827073b2ac0984ed21 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 27 Feb 2017 20:58:48 +0000 Subject: drm/i915: Signal first fence from irq handler if complete As execlists and other non-semaphore multi-engine devices coordinate between engines using interrupts, we can shave off a few 10s of microsecond of scheduling latency by doing the fence signaling from the interrupt as opposed to a RT kthread. (Realistically the delay adds about 1% to an individual cross-engine workload.) We only signal the first fence in order to limit the amount of work we move into the interrupt handler. We also have to remember that our breadcrumbs may be unordered with respect to the interrupt and so we still require the waiter process to perform some heavyweight coherency fixups, as well as traversing the tree of waiters. v2: No need for early exit in irq handler - it breaks the flow between patches and prevents the tracepoint v3: Restore rcu hold across irq signaling of request Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Mika Kuoppala Reviewed-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/20170227205850.2828-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_request.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/gpu/drm/i915/i915_gem_request.h') diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h index 5f73d8c0a38a..0efee879df23 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.h +++ b/drivers/gpu/drm/i915/i915_gem_request.h @@ -32,10 +32,12 @@ struct drm_file; struct drm_i915_gem_object; +struct drm_i915_gem_request; struct intel_wait { struct rb_node node; struct task_struct *tsk; + struct drm_i915_gem_request *request; u32 seqno; }; -- cgit v1.2.3-59-g8ed1b