[PATCH] drm/i915: Only grab timestamps when needed

[PATCH] drm/i915: Only grab timestamps when needed

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

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 <tvrtko.ursulin@intel.com>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

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;
 
-- 
1.9.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

✗ Fi.CI.BAT: warning for drm/i915: Only grab timestamps when needed

[Patchwork]

== Summary ==

Built on 615fbad7f4cea73b1a8eccdcc942c8ca1a708dab drm-intel-nightly: 2016y-01m-15d-09h-46m-32s UTC integration manifest

Test gem_storedw_loop:
        Subgroup basic-render:
                pass       -> DMESG-WARN (bdw-ultra) UNSTABLE
Test kms_flip:
        Subgroup basic-flip-vs-modeset:
                dmesg-warn -> PASS       (skl-i5k-2)
Test kms_pipe_crc_basic:
        Subgroup read-crc-pipe-a-frame-sequence:
                pass       -> DMESG-WARN (byt-nuc)

bdw-nuci7        total:138  pass:128  dwarn:1   dfail:0   fail:0   skip:9  
bdw-ultra        total:138  pass:131  dwarn:1   dfail:0   fail:0   skip:6  
bsw-nuc-2        total:141  pass:115  dwarn:2   dfail:0   fail:0   skip:24 
byt-nuc          total:141  pass:122  dwarn:4   dfail:0   fail:0   skip:15 
hsw-brixbox      total:141  pass:134  dwarn:0   dfail:0   fail:0   skip:7  
hsw-gt2          total:141  pass:137  dwarn:0   dfail:0   fail:0   skip:4  
ilk-hp8440p      total:141  pass:101  dwarn:3   dfail:0   fail:0   skip:37 
ivb-t430s        total:135  pass:122  dwarn:3   dfail:4   fail:0   skip:6  
skl-i5k-2        total:141  pass:132  dwarn:1   dfail:0   fail:0   skip:8  
skl-i7k-2        total:141  pass:132  dwarn:1   dfail:0   fail:0   skip:8  
snb-dellxps      total:141  pass:122  dwarn:5   dfail:0   fail:0   skip:14 
snb-x220t        total:141  pass:122  dwarn:5   dfail:0   fail:1   skip:13 

Results at /archive/results/CI_IGT_test/Patchwork_1200/

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx