On 25/03/2023 00:00, Rob Clark wrote:
From: Rob Clark <robdclark@xxxxxxxxxxxx>
If userspace asked for a timeout greater than zero, but less than a
jiffy, they clearly weren't planning on spinning. So it is better
to round up to one.
This fixes an issue with supertuxkart that was (for some reason)
spinning on a gl sync with 1ms timeout. CPU time for a demo lap
drops from:
15.83user 20.98system 0:47.46elapsed 77%CPU
to:
8.84user 2.30system 0:46.67elapsed 23%CPU
Interesting. We potentially increased the timeout, but the overall
(elapsed) time has decreased. Nevertheless:
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_drv.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 9f0c184b02a0..7936aa6cad03 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -548,7 +548,7 @@ static inline unsigned long timeout_to_jiffies(const ktime_t *timeout)
remaining_jiffies = ktime_divns(rem, NSEC_PER_SEC / HZ);
}
- return clamp(remaining_jiffies, 0LL, (s64)INT_MAX);
+ return clamp(remaining_jiffies, 1LL, (s64)INT_MAX);
}
/* Driver helpers */
--
With best wishes
Dmitry
