On Wed, Apr 29, 2020 at 11:19:07AM +0000, kl@kl.wtf wrote:
April 28, 2020 5:14 PM, "Daniel Vetter" daniel@ffwll.ch wrote:
On Fri, Apr 24, 2020 at 06:26:15PM +0200, Kenny Levinsen wrote:
Some processes, such as systemd, are only polling for EPOLLERR|EPOLLHUP. As drm_file uses unkeyed wakeups, such a poll can receive many spurious wakeups from uninteresting events if, for example, the file description is subscribed to vblank events. This is the case with systemd, as it polls a file description from logind that is shared with the users' compositor.
Use keyed wakeups to allow the wakeup target to more efficiently discard these uninteresting events.
Signed-off-by: Kenny Levinsen kl@kl.wtf
Hm I applied v1 and I'm not spotting what's different here, and there's no changelog explaining what changed ...
Please send a fixup if there's anything important missing. -Daniel
It's only the summary that differed as you and sravn requested in #dri-devel, so it's probably fine.
I should have explained the change. I'm still trying to get the hang of the email-based workflow. :)
Oops sorry, I generally run as a stateless maintainer so forgot :-/
And yes email based workflow is full of warts, it's a pain. -Daniel
Best regards, Kenny Levinsen
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
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch