From: Hans Verkuil hverkuil@xs4all.nl
[ 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 --- drivers/media/test-drivers/vivid/vivid-kthread-cap.c | 11 ++++++++--- drivers/media/test-drivers/vivid/vivid-kthread-out.c | 11 ++++++++--- .../media/test-drivers/vivid/vivid-kthread-touch.c | 11 ++++++++--- drivers/media/test-drivers/vivid/vivid-sdr-cap.c | 11 ++++++++--- 4 files changed, 32 insertions(+), 12 deletions(-)
diff --git a/drivers/media/test-drivers/vivid/vivid-kthread-cap.c b/drivers/media/test-drivers/vivid/vivid-kthread-cap.c index 42048727d7ff3..b8cdffc9a1e9e 100644 --- a/drivers/media/test-drivers/vivid/vivid-kthread-cap.c +++ b/drivers/media/test-drivers/vivid/vivid-kthread-cap.c @@ -765,9 +765,14 @@ 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; diff --git a/drivers/media/test-drivers/vivid/vivid-kthread-out.c b/drivers/media/test-drivers/vivid/vivid-kthread-out.c index fac6208b51da8..015a7b166a1e6 100644 --- a/drivers/media/test-drivers/vivid/vivid-kthread-out.c +++ b/drivers/media/test-drivers/vivid/vivid-kthread-out.c @@ -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; diff --git a/drivers/media/test-drivers/vivid/vivid-kthread-touch.c b/drivers/media/test-drivers/vivid/vivid-kthread-touch.c index fa711ee36a3fb..c862689786b69 100644 --- a/drivers/media/test-drivers/vivid/vivid-kthread-touch.c +++ b/drivers/media/test-drivers/vivid/vivid-kthread-touch.c @@ -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; diff --git a/drivers/media/test-drivers/vivid/vivid-sdr-cap.c b/drivers/media/test-drivers/vivid/vivid-sdr-cap.c index a81f26b769883..1dd59c710dae7 100644 --- a/drivers/media/test-drivers/vivid/vivid-sdr-cap.c +++ b/drivers/media/test-drivers/vivid/vivid-sdr-cap.c @@ -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;