[Intel-gfx] [PATCH] drm/i915: Break up error capture compression loops with cond_resched()

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> As the error capture will compress user buffers as directed to by the
> user, it can take an arbitrary amount of time and space. Break up the
> compression loops with a call to cond_resched(), that will allow other
> processes to schedule (avoiding the soft lockups) and also serve as a
> warning should we try to make this loop atomic in the future.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: stable at vger.kernel.org

Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/i915_gpu_error.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 6a3a2ce0b394..6551ff04d5a6 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -311,6 +311,8 @@ static int compress_page(struct i915_vma_compress *c,
>  
>  		if (zlib_deflate(zstream, Z_NO_FLUSH) != Z_OK)
>  			return -EIO;
> +
> +		cond_resched();
>  	} while (zstream->avail_in);
>  
>  	/* Fallback to uncompressed if we increase size? */
> @@ -397,6 +399,7 @@ static int compress_page(struct i915_vma_compress *c,
>  	if (!(wc && i915_memcpy_from_wc(ptr, src, PAGE_SIZE)))
>  		memcpy(ptr, src, PAGE_SIZE);
>  	dst->pages[dst->page_count++] = ptr;
> +	cond_resched();
>  
>  	return 0;
>  }
> -- 
> 2.20.1