linux-kernel - Re: [PATCH v2 6/7] media: chips-media: wave5: Reduce high CPU load

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f94e84af0a6ea09fd111f5a1ec9b0fadc9f6d4de.camel@collabora.com>
Date: Fri, 23 May 2025 13:43:19 -0400
From: Nicolas Dufresne <nicolas.dufresne@...labora.com>
To: "Jackson.lee" <jackson.lee@...psnmedia.com>, mchehab@...nel.org, 
	hverkuil-cisco@...all.nl, sebastian.fricke@...labora.com, 
	bob.beckett@...labora.com, dafna.hirschfeld@...labora.com
Cc: linux-media@...r.kernel.org, linux-kernel@...r.kernel.org, 
	lafley.kim@...psnmedia.com, b-brnich@...com, hverkuil@...all.nl, 
	nas.chung@...psnmedia.com
Subject: Re: [PATCH v2 6/7] media: chips-media: wave5: Reduce high CPU load

Hi,

Le jeudi 22 mai 2025 à 16:26 +0900, Jackson.lee a écrit :
> From: Jackson Lee <jackson.lee@...psnmedia.com>
> 
> Since applying changes for performance improvement of decoder,
> there was a problem related to high CPU load.
> CPU load was more than 4 times when comparing CPU load.
> The root cause was the device_run was called many times even if
> there was no bitstream which should be queued.

You should squash this.

Nicolas

> 
> Signed-off-by: Jackson Lee <jackson.lee@...psnmedia.com>
> Signed-off-by: Nas Chung <nas.chung@...psnmedia.com>
> ---
>  .../media/platform/chips-media/wave5/wave5-vpu-dec.c | 12 +++++++++---
>  .../media/platform/chips-media/wave5/wave5-vpuapi.h  |  1 +
>  2 files changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c b/drivers/media/platform/chips-
> media/wave5/wave5-vpu-dec.c
> index 719c5527eb7f..421a9e1a6f15 100644
> --- a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
> +++ b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
> @@ -1280,10 +1280,13 @@ static void wave5_vpu_dec_buf_queue(struct vb2_buffer *vb)
>  		__func__, vb->type, vb->index, vb2_plane_size(&vbuf->vb2_buf, 0),
>  		vb2_plane_size(&vbuf->vb2_buf, 1), vb2_plane_size(&vbuf->vb2_buf, 2));
>  
> -	if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> +	if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
> +		if (inst->empty_queue)
> +			inst->empty_queue = false;
>  		wave5_vpu_dec_buf_queue_src(vb);
> -	else if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> +	} else if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
>  		wave5_vpu_dec_buf_queue_dst(vb);
> +	}
>  }
>  
>  static int wave5_vpu_dec_allocate_ring_buffer(struct vpu_instance *inst)
> @@ -1474,6 +1477,7 @@ static void wave5_vpu_dec_stop_streaming(struct vb2_queue *q)
>  
>  	dev_dbg(inst->dev->dev, "%s: type: %u\n", __func__, q->type);
>  	pm_runtime_resume_and_get(inst->dev->dev);
> +	inst->empty_queue = false;
>  
>  	while (check_cmd) {
>  		struct queue_status_info q_status;
> @@ -1592,6 +1596,7 @@ static void wave5_vpu_dec_device_run(void *priv)
>  				inst->queuing_num == 0 &&
>  				inst->state == VPU_INST_STATE_PIC_RUN) {
>  			dev_dbg(inst->dev->dev, "%s: no bitstream for feeding, so skip ", __func__);
> +			inst->empty_queue = true;
>  			goto finish_job_and_return;
>  		}
>  	}
> @@ -1737,7 +1742,8 @@ static int wave5_vpu_dec_job_ready(void *priv)
>  				"No capture buffer ready to decode!\n");
>  			break;
>  		} else if (!wave5_is_draining_or_eos(inst) &&
> -			   !v4l2_m2m_num_src_bufs_ready(m2m_ctx)) {
> +			   (!v4l2_m2m_num_src_bufs_ready(m2m_ctx) ||
> +			    inst->empty_queue)) {
>  			dev_dbg(inst->dev->dev,
>  				"No bitstream data to decode!\n");
>  			break;
> diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h b/drivers/media/platform/chips-media/wave5/wave5-
> vpuapi.h
> index fd0aef0bac4e..f2596af08cdf 100644
> --- a/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h
> +++ b/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h
> @@ -821,6 +821,7 @@ struct vpu_instance {
>  	bool retry; /* retry to feed bitstream if failure reason is WAVE5_SYSERR_QUEUEING_FAIL*/
>  	int queuing_num; /* check if there is input buffer or not */
>  	struct mutex feed_lock; /* lock for feeding bitstream buffers */
> +	bool empty_queue;
>  	struct vpu_buf bitstream_vbuf;
>  	dma_addr_t last_rd_ptr;
>  	size_t remaining_consumed_bytes;