Re: [PATCH v2 01/23] drm/msm: Pre-allocate hw_fence

Christian König
2023-03-20T17:01:10Z

Am 20.03.23 um 15:43 schrieb Rob Clark:
> From: Rob Clark <robdclark@chromium.org>
>
> Avoid allocating memory in job_run() by pre-allocating the hw_fence.
>
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
> drivers/gpu/drm/msm/msm_fence.c | 12 +++++++++---
> drivers/gpu/drm/msm/msm_fence.h | 3 ++-
> drivers/gpu/drm/msm/msm_gem_submit.c | 7 +++++++
> drivers/gpu/drm/msm/msm_ringbuffer.c | 2 +-
> 4 files changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_fence.c b/drivers/gpu/drm/msm/msm_fence.c
> index 56641408ea74..bab3d84f1686 100644
> --- a/drivers/gpu/drm/msm/msm_fence.c
> +++ b/drivers/gpu/drm/msm/msm_fence.c
> @@ -99,7 +99,7 @@ static const struct dma_fence_ops msm_fence_ops = {
> };
>
> struct dma_fence *
> -msm_fence_alloc(struct msm_fence_context *fctx)
> +msm_fence_alloc(void)
> {
> struct msm_fence *f;
>
> @@ -107,10 +107,16 @@ msm_fence_alloc(struct msm_fence_context *fctx)
> if (!f)
> return ERR_PTR(-ENOMEM);
>
> + return &f->base;
> +}
> +
> +void
> +msm_fence_init(struct dma_fence *fence, struct msm_fence_context *fctx)
> +{
> + struct msm_fence *f = to_msm_fence(fence);
> +
> f->fctx = fctx;
>
> dma_fence_init(&f->base, &msm_fence_ops, &fctx->spinlock,
> fctx->context, ++fctx->last_fence);
> -
> - return &f->base;
> }
> diff --git a/drivers/gpu/drm/msm/msm_fence.h b/drivers/gpu/drm/msm/msm_fence.h
> index 7f1798c54cd1..f913fa22d8fe 100644
> --- a/drivers/gpu/drm/msm/msm_fence.h
> +++ b/drivers/gpu/drm/msm/msm_fence.h
> @@ -61,7 +61,8 @@ void msm_fence_context_free(struct msm_fence_context *fctx);
> bool msm_fence_completed(struct msm_fence_context *fctx, uint32_t fence);
> void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence);
>
> -struct dma_fence * msm_fence_alloc(struct msm_fence_context *fctx);
> +struct dma_fence * msm_fence_alloc(void);
> +void msm_fence_init(struct dma_fence *fence, struct msm_fence_context *fctx);
>
> static inline bool
> fence_before(uint32_t a, uint32_t b)
> diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
> index be4bf77103cd..2570c018b0cb 100644
> --- a/drivers/gpu/drm/msm/msm_gem_submit.c
> +++ b/drivers/gpu/drm/msm/msm_gem_submit.c
> @@ -41,6 +41,13 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev,
> if (!submit)
> return ERR_PTR(-ENOMEM);
>
> + submit->hw_fence = msm_fence_alloc();
> + if (IS_ERR(submit->hw_fence)) {
> + ret = PTR_ERR(submit->hw_fence);
> + kfree(submit);
> + return ERR_PTR(ret);
> + }
> +
> ret = drm_sched_job_init(&submit->base, queue->entity, queue);
> if (ret) {
> kfree(submit);

You probably need some error handling here or otherwise leak
submit->hw_fence.

Apart from that looks good to me.

Christian.

> diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c
> index 57a8e9564540..a62b45e5a8c3 100644
> --- a/drivers/gpu/drm/msm/msm_ringbuffer.c
> +++ b/drivers/gpu/drm/msm/msm_ringbuffer.c
> @@ -18,7 +18,7 @@ static struct dma_fence *msm_job_run(struct drm_sched_job *job)
> struct msm_gpu *gpu = submit->gpu;
> int i;
>
> - submit->hw_fence = msm_fence_alloc(fctx);
> + msm_fence_init(submit->hw_fence, fctx);
>
> for (i = 0; i < submit->nr_bos; i++) {
> struct drm_gem_object *obj = &submit->bos[i].obj->base;