[Mesa-dev] [PATCH v2 16/37] panfrost: Don't return imported/exported BOs to the cache

[Alyssa Rosenzweig]

R-b. Wonder why this never broke anything else either.

On Mon, Sep 16, 2019 at 11:36:54AM +0200, Boris Brezillon wrote:
> We don't know who else is using the BO in that case, and thus shouldn't
> re-use it for something else.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> ---
>  src/gallium/drivers/panfrost/pan_bo.c | 5 +++++
>  src/gallium/drivers/panfrost/pan_bo.h | 4 ++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/src/gallium/drivers/panfrost/pan_bo.c b/src/gallium/drivers/panfrost/pan_bo.c
> index 5d0f296cc4fb..209d1e0d71e5 100644
> --- a/src/gallium/drivers/panfrost/pan_bo.c
> +++ b/src/gallium/drivers/panfrost/pan_bo.c
> @@ -182,6 +182,9 @@ panfrost_bo_cache_put(struct panfrost_bo *bo)
>  {
>          struct panfrost_screen *screen = bo->screen;
>  
> +        if (bo->flags & PAN_BO_DONT_REUSE)
> +                return false;
> +
>          pthread_mutex_lock(&screen->bo_cache_lock);
>          struct list_head *bucket = pan_bucket(screen, bo->size);
>          struct drm_panfrost_madvise madv;
> @@ -352,6 +355,7 @@ panfrost_bo_import(struct panfrost_screen *screen, int fd)
>          bo->gem_handle = gem_handle;
>          bo->gpu = (mali_ptr) get_bo_offset.offset;
>          bo->size = lseek(fd, 0, SEEK_END);
> +        bo->flags |= PAN_BO_DONT_REUSE;
>          assert(bo->size > 0);
>          pipe_reference_init(&bo->reference, 1);
>  
> @@ -372,6 +376,7 @@ panfrost_bo_export(struct panfrost_bo *bo)
>          if (ret == -1)
>                  return -1;
>  
> +        bo->flags |= PAN_BO_DONT_REUSE;
>          return args.fd;
>  }
>  
> diff --git a/src/gallium/drivers/panfrost/pan_bo.h b/src/gallium/drivers/panfrost/pan_bo.h
> index 2858d3782eff..33fbddff3369 100644
> --- a/src/gallium/drivers/panfrost/pan_bo.h
> +++ b/src/gallium/drivers/panfrost/pan_bo.h
> @@ -52,6 +52,10 @@ struct panfrost_screen;
>   * (semantically distinct from INVISIBLE, which cannot never be mmaped) */
>  #define PAN_BO_DELAY_MMAP         (1 << 4)
>  
> +/* Some BOs shouldn't be returned back to the reuse BO cache, use this flag to
> + * let the BO logic know about this contraint. */
> +#define PAN_BO_DONT_REUSE         (1 << 5)
> +
>  struct panfrost_bo {
>          /* Must be first for casting */
>          struct list_head link;
> -- 
> 2.21.0