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media: test-drivers: vivid: don't call schedule in loop

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[ Upstream commit e4740118b752005cbed339aec9a1d1c43620e0b9 ]

Artem reported that the CPU load was 100% when capturing from
vivid at low resolution with ffmpeg.

This was caused by:

while (time_is_after_jiffies(cur_jiffies + wait_jiffies) &&
       !kthread_should_stop())
        schedule();

If there are no other processes running that can be scheduled,
then this is basically a busy-loop.

Change it to wait_event_interruptible_timeout() which doesn't
have that problem.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Reported-by: Artem S. Tashkinov <aros@gmx.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219570
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Hans Verkuil
2024-12-09 16:00:16 +01:00
committed by Greg Kroah-Hartman
parent 2fe6284364
commit 3770acff31
4 changed files with 32 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/media/test-drivers/vivid/vivid-kthread-cap.c
View File

@@ -789,9 +789,14 @@ static int vivid_thread_vid_cap(void *data)
next_jiffies_since_start = jiffies_since_start;
wait_jiffies = next_jiffies_since_start - jiffies_since_start;
while (time_is_after_jiffies(cur_jiffies + wait_jiffies) &&
!kthread_should_stop())
schedule();
if (!time_is_after_jiffies(cur_jiffies + wait_jiffies))
continue;
wait_queue_head_t wait;
init_waitqueue_head(&wait);
wait_event_interruptible_timeout(wait, kthread_should_stop(),
cur_jiffies + wait_jiffies - jiffies);
}
dprintk(dev, 1, "Video Capture Thread End\n");
return 0;

11
drivers/media/test-drivers/vivid/vivid-kthread-out.c
View File

@@ -235,9 +235,14 @@ static int vivid_thread_vid_out(void *data)
next_jiffies_since_start = jiffies_since_start;
wait_jiffies = next_jiffies_since_start - jiffies_since_start;
while (time_is_after_jiffies(cur_jiffies + wait_jiffies) &&
!kthread_should_stop())
schedule();
if (!time_is_after_jiffies(cur_jiffies + wait_jiffies))
continue;
wait_queue_head_t wait;
init_waitqueue_head(&wait);
wait_event_interruptible_timeout(wait, kthread_should_stop(),
cur_jiffies + wait_jiffies - jiffies);
}
dprintk(dev, 1, "Video Output Thread End\n");
return 0;

11
drivers/media/test-drivers/vivid/vivid-kthread-touch.c
View File

@@ -135,9 +135,14 @@ static int vivid_thread_touch_cap(void *data)
next_jiffies_since_start = jiffies_since_start;
wait_jiffies = next_jiffies_since_start - jiffies_since_start;
while (time_is_after_jiffies(cur_jiffies + wait_jiffies) &&
!kthread_should_stop())
schedule();
if (!time_is_after_jiffies(cur_jiffies + wait_jiffies))
continue;
wait_queue_head_t wait;
init_waitqueue_head(&wait);
wait_event_interruptible_timeout(wait, kthread_should_stop(),
cur_jiffies + wait_jiffies - jiffies);
}
dprintk(dev, 1, "Touch Capture Thread End\n");
return 0;

11
drivers/media/test-drivers/vivid/vivid-sdr-cap.c
View File

@@ -206,9 +206,14 @@ static int vivid_thread_sdr_cap(void *data)
next_jiffies_since_start = jiffies_since_start;
wait_jiffies = next_jiffies_since_start - jiffies_since_start;
while (time_is_after_jiffies(cur_jiffies + wait_jiffies) &&
!kthread_should_stop())
schedule();
if (!time_is_after_jiffies(cur_jiffies + wait_jiffies))
continue;
wait_queue_head_t wait;
init_waitqueue_head(&wait);
wait_event_interruptible_timeout(wait, kthread_should_stop(),
cur_jiffies + wait_jiffies - jiffies);
}
dprintk(dev, 1, "SDR Capture Thread End\n");
return 0;