From: Tvrtko Ursulin Date: Fri, 15 Jan 2016 15:11:12 +0000 (+0000) Subject: drm/i915: Only grab timestamps when needed X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e0313db047c2f2e368c95a8f03653f9723678e82;p=linux-beck.git drm/i915: Only grab timestamps when needed No need to call ktime_get_raw_ns twice per unlimited wait and can also elimate a local variable. v2: Added comment about silencing the compiler warning. (Daniel Vetter) Signed-off-by: Tvrtko Ursulin Reviewed-by: Dave Gordon Acked-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1452870672-13901-1-git-send-email-tvrtko.ursulin@linux.intel.com --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index ddc21d4b388d..6b0102da859c 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1251,7 +1251,7 @@ int __i915_wait_request(struct drm_i915_gem_request *req, int state = interruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE; DEFINE_WAIT(wait); unsigned long timeout_expire; - s64 before, now; + s64 before = 0; /* Only to silence a compiler warning. */ int ret; WARN(!intel_irqs_enabled(dev_priv), "IRQs disabled"); @@ -1271,14 +1271,17 @@ int __i915_wait_request(struct drm_i915_gem_request *req, return -ETIME; timeout_expire = jiffies + nsecs_to_jiffies_timeout(*timeout); + + /* + * Record current time in case interrupted by signal, or wedged. + */ + before = ktime_get_raw_ns(); } if (INTEL_INFO(dev_priv)->gen >= 6) gen6_rps_boost(dev_priv, rps, req->emitted_jiffies); - /* Record current time in case interrupted by signal, or wedged */ trace_i915_gem_request_wait_begin(req); - before = ktime_get_raw_ns(); /* Optimistic spin for the next jiffie before touching IRQs */ ret = __i915_spin_request(req, state); @@ -1343,11 +1346,10 @@ int __i915_wait_request(struct drm_i915_gem_request *req, finish_wait(&ring->irq_queue, &wait); out: - now = ktime_get_raw_ns(); trace_i915_gem_request_wait_end(req); if (timeout) { - s64 tres = *timeout - (now - before); + s64 tres = *timeout - (ktime_get_raw_ns() - before); *timeout = tres < 0 ? 0 : tres;