[Intel-gfx] [PATCH] drm/i915: Suppress oom warning for shmemfs object allocation failure

[Matthew Auld]

On 20/07/2022 13:23, Nirmoy Das wrote:
> From: Chris Wilson <chris at chris-wilson.co.uk>
> 
> We report object allocation failures to userspace with ENOMEM, yet we
> still show the memory warning after failing to shrink device allocated
> pages. While this warning is similar to other system page allocation
> failures, it is superfluous to the ENOMEM provided directly to
> userspace.
> 
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4936

Is it not possible that this triggers OOM warning when calling 
sg_alloc_table() or similar? I guess shmem_read_mapping_page_gfp() is 
the most likely spot where this triggers OOM, but that doesn't have to 
be the case?

> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
> ---
>   drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> index 4eed3dd90ba8..4466173e1bcc 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> @@ -137,7 +137,7 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st,
>   				 * trigger the out-of-memory killer and for
>   				 * this we want __GFP_RETRY_MAYFAIL.
>   				 */
> -				gfp |= __GFP_RETRY_MAYFAIL;
> +				gfp |= __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
>   			}
>   		} while (1);
>