Replace the open-coded polling with schedule() in vmw_fallback_wait()
by schedule_hrtimeout(). The old code wakes up at jiffy granularity and
leads to unnecessary CPU wakeups during fence waits.
schedule_hrtimeout() provides high-resolution sleep with finer control,
reducing CPU utilization without affecting fence correctness. For the
non-interruptible case, use schedule_timeout_uninterruptible().
Signed-off-by: Pavan Bobba <opensource...@gmail.com>
---
drivers/gpu/drm/vmwgfx/vmwgfx_irq.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
b/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
index 05773eb394d3..64045b0efafc 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
@@ -202,16 +202,12 @@ int vmw_fallback_wait(struct vmw_private *dev_priv,
if (lazy)
schedule_timeout(1);
else if ((++count & 0x0F) == 0) {
- /**
- * FIXME: Use schedule_hr_timeout here for
- * newer kernels and lower CPU utilization.
- */
-
- __set_current_state(TASK_RUNNING);
- schedule();
- __set_current_state((interruptible) ?
- TASK_INTERRUPTIBLE :
- TASK_UNINTERRUPTIBLE);
+ ktime_t delta = ktime_set(0, NSEC_PER_MSEC);
+
+ if (interruptible)
+ schedule_hrtimeout(&delta, HRTIMER_MODE_REL);
+ else
+ schedule_timeout_uninterruptible(delta);
}
if (interruptible && signal_pending(current)) {
ret = -ERESTARTSYS;
--
2.43.0
