On Fri, Apr 24, 2020 at 04:51:03PM +0200, Kenny Levinsen wrote:
Some processes, such as systemd, are only polling for EPOLLERR|EPOLLHUP. As drm_file uses unkeyed wakeups, such a poll receives many spurious wakeups from uninteresting events.
Use keyed wakeups to allow the wakeup target to more efficiently discard these uninteresting events.
Signed-off-by: Kenny Levinsen kl@kl.wtf
intel-gfx CI is happy, I'm living with the illusion that this seems to loook correct (linux kernel poll code is too much magic for me). Thanks for your patch, queued up in drm-misc-next for 5.8.
Cheers, Daniel
drivers/gpu/drm/drm_file.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index c4c704e01961..ec25b3d979d9 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -608,7 +608,8 @@ ssize_t drm_read(struct file *filp, char __user *buffer, file_priv->event_space -= length; list_add(&e->link, &file_priv->event_list); spin_unlock_irq(&dev->event_lock);
wake_up_interruptible(&file_priv->event_wait);
wake_up_interruptible_poll(&file_priv->event_wait,EPOLLIN | EPOLLRDNORM); break; }@@ -804,7 +805,8 @@ void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e) list_del(&e->pending_link); list_add_tail(&e->link, &e->file_priv->event_list);
- wake_up_interruptible(&e->file_priv->event_wait);
- wake_up_interruptible_poll(&e->file_priv->event_wait,
EPOLLIN | EPOLLRDNORM);} EXPORT_SYMBOL(drm_send_event_locked);
-- 2.26.1