From 91e19db7e3955389644261a631990c8c581e2f72 Mon Sep 17 00:00:00 2001
From: Kenny Levinsen <kl@kl.wtf>
Date: Fri, 24 Apr 2020 16:51:03 +0200
Subject: drm: make drm_file use keyed wakeups
Git-commit: 87189b78959c10c454477cce5cb9836c2ee5c730
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
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>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200424145103.3048-1-kl@kl.wtf
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
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 6a1f6c802415..2f12b8c1d01c 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -610,7 +610,8 @@ 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;
}
@@ -806,7 +807,8 @@ 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);
--
2.28.0