[v5,4/5] libcamera: swstats_cpu: Take MappedFrameBuffer in processFrame()

26806 diff mbox series

As the only current user - DebayerEGL::process() - already has the buffer
mapped. Currently this shouldn't impact performance as the kernel should
already avoid remapping the dmabuf - i.e. we implicitly benefit from the
fact that the mentioned function holds its mapping during the runtime of
processFrame(). In a following commit DebayerEGL::process() will change
in a way that would make keeping the mapping counter-intuitive. Thus
this change ensures we'll not accidentally start mapping the buffer
twice per frame.

Signed-off-by: Robert Mader <robert.mader@collabora.com>
---
 include/libcamera/internal/software_isp/swstats_cpu.h |  2 +-
 src/libcamera/software_isp/debayer_egl.cpp            |  2 +-
 src/libcamera/software_isp/swstats_cpu.cpp            | 11 ++---------
 3 files changed, 4 insertions(+), 11 deletions(-)

Quoting Robert Mader (2026-05-27 09:15:33)
> As the only current user - DebayerEGL::process() - already has the buffer
> mapped. Currently this shouldn't impact performance as the kernel should
> already avoid remapping the dmabuf - i.e. we implicitly benefit from the
> fact that the mentioned function holds its mapping during the runtime of
> processFrame(). In a following commit DebayerEGL::process() will change
> in a way that would make keeping the mapping counter-intuitive. Thus
> this change ensures we'll not accidentally start mapping the buffer
> twice per frame.
> 


Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

> Signed-off-by: Robert Mader <robert.mader@collabora.com>
> ---
>  include/libcamera/internal/software_isp/swstats_cpu.h |  2 +-
>  src/libcamera/software_isp/debayer_egl.cpp            |  2 +-
>  src/libcamera/software_isp/swstats_cpu.cpp            | 11 ++---------
>  3 files changed, 4 insertions(+), 11 deletions(-)
> 
> diff --git a/include/libcamera/internal/software_isp/swstats_cpu.h b/include/libcamera/internal/software_isp/swstats_cpu.h
> index b5348c6fe..686e3d981 100644
> --- a/include/libcamera/internal/software_isp/swstats_cpu.h
> +++ b/include/libcamera/internal/software_isp/swstats_cpu.h
> @@ -56,7 +56,7 @@ public:
>         void setWindow(const Rectangle &window);
>         void startFrame(uint32_t frame);
>         void finishFrame(uint32_t frame, uint32_t bufferId);
> -       void processFrame(uint32_t frame, uint32_t bufferId, FrameBuffer *input);
> +       void processFrame(uint32_t frame, uint32_t bufferId, MappedFrameBuffer &input);
>  
>         void processLine0(uint32_t frame, unsigned int y, const uint8_t *src[], unsigned int statsBufferIndex = 0)
>         {
> diff --git a/src/libcamera/software_isp/debayer_egl.cpp b/src/libcamera/software_isp/debayer_egl.cpp
> index 696498a58..d08634640 100644
> --- a/src/libcamera/software_isp/debayer_egl.cpp
> +++ b/src/libcamera/software_isp/debayer_egl.cpp
> @@ -555,7 +555,7 @@ void DebayerEGL::process(uint32_t frame, FrameBuffer *input, FrameBuffer *output
>         metadata.planes()[0].bytesused = output->planes()[0].length;
>  
>         /* Calculate stats for the whole frame */
> -       stats_->processFrame(frame, 0, input);
> +       stats_->processFrame(frame, 0, in);
>         dmaSyncers.clear();
>  
>         egl_.syncOutput();
> diff --git a/src/libcamera/software_isp/swstats_cpu.cpp b/src/libcamera/software_isp/swstats_cpu.cpp
> index 0815ec9a3..fb7a5301d 100644
> --- a/src/libcamera/software_isp/swstats_cpu.cpp
> +++ b/src/libcamera/software_isp/swstats_cpu.cpp
> @@ -543,7 +543,7 @@ void SwStatsCpu::processBayerFrame2(MappedFrameBuffer &in)
>   *
>   * This may only be called after a successful setWindow() call.
>   */
> -void SwStatsCpu::processFrame(uint32_t frame, uint32_t bufferId, FrameBuffer *input)
> +void SwStatsCpu::processFrame(uint32_t frame, uint32_t bufferId, MappedFrameBuffer &input)
>  {
>         if (frame % kStatPerNumFrames) {
>                 finishFrame(frame, bufferId);
> @@ -552,14 +552,7 @@ void SwStatsCpu::processFrame(uint32_t frame, uint32_t bufferId, FrameBuffer *in
>  
>         bench_.startFrame();
>         startFrame(frame);
> -
> -       MappedFrameBuffer in(input, MappedFrameBuffer::MapFlag::Read);
> -       if (!in.isValid()) {
> -               LOG(SwStatsCpu, Error) << "mmap-ing buffer(s) failed";
> -               return;
> -       }
> -
> -       (this->*processFrame_)(in);
> +       (this->*processFrame_)(input);
>         finishFrame(frame, bufferId);
>         bench_.finishFrame();
>  }
> -- 
> 2.54.0
>