When using GMSL camera, vi-output process caused high CPU load

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
1

Hi, I’m using the Jetson AGX Orin based computer and IMX.390 based GMSL Camera. When capturing camera frames with gstreamer, “vi-output” process caused high CPU load (50~70%).

Environment:

  • Jetson: AGX Orin
  • L4T version: R35.3.1
  • Image sensor: imx.390
  • gstreamer command:
gst-launch-1.0 v4l2src device="/dev/video0" ! "video/x-raw, format=(string)UYVY, width=(int)1920, height=(int)1080" ! nvvidconv ! "video/x-raw(memory:NVMM), width=480, height=270, format=(string)I420" ! nvvidconv ! xvimagesink sync=false

I tried a function trace of “vi-output” and guessed “tegra_channel_kthread_capture_enqueue” thread was in a busy loop.

 vi-output, imx3-10393   [005] ...1 25802.981586: kthread_should_stop <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981587: kthread_should_stop <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981587: kthread_should_stop <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981587: _raw_spin_lock_irqsave <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] d..2 25802.981587: _raw_spin_unlock_irqrestore <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981587: kthread_should_stop <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981587: kthread_should_stop <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981588: kthread_should_stop <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981588: _raw_spin_lock_irqsave <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] d..2 25802.981588: _raw_spin_unlock_irqrestore <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981588: kthread_should_stop <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981588: kthread_should_stop <-tegra_channel_kthread_capture_enqueue
 vi-output, imx3-10393   [005] ...1 25802.981589: kthread_should_stop <-tegra_channel_kthread_capture_enqueue

I checked dmesg and found this warning.

corr_err: discarding frame 0, flags: 0, err_data

I thought this error might be the cause. So I applied this patch and the “vi-output” process became low CPU load.

modified   kernel/nvidia/drivers/media/platform/tegra/camera/vi/vi5_fops.c
@@ -691,6 +691,7 @@ static int tegra_channel_kthread_capture_enqueue(void *data)
 					< (chan->capture_queue_depth * chan->valid_ports))) {
 				spin_unlock_irqrestore(
 					&chan->capture_state_lock, flags);
+			    dequeue_buffer(chan, false);
 				break;
 			}
 			spin_unlock_irqrestore(&chan->capture_state_lock,

Is this patch correct? Or if there is another best solution, I would like to know.

3

Does any side effect for your modification?
Try increase the timeout instead of add dequeue_buffer()

define CAPTURE_TIMEOUT_MS 2500

4

Hi.

Thank you for your help. I tried changing the timeout value but it did not work.

With my modification, I have confirmed that running the camera for several hours does not cause any problems. However, I do not know the extent to which this modification will have side effects.

5

How long did you increase?

6

I changed to 25000.

@@ -39,7 +39,7 @@
 #define VI_CHANNEL_DEV "/dev/capture-vi-channel"
 #define VI_CHAN_PATH_MAX 40
 
-#define CAPTURE_TIMEOUT_MS	2500
+#define CAPTURE_TIMEOUT_MS	25000
 
 static const struct vi_capture_setup default_setup = {
 	.channel_flags = 0
7

Did you apply the kernel Image to verify the modification?

Thanks

8

Yes. I checked CAPTURE_TIMEOUT_MS by debug log.

9

Thanks for your confirm.
Please take time to verify your solution to confirm if any side effect.

Thanks

11

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12

Please help to verify this patch.

0001-camera-vi5-fix-stream-on-off-memory-leakage.patch (6.4 KB)
0001-vi5-continue-captures-even-after-corr-errors.patch (2.3 KB)

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