[Intel-gfx] [PATCH 5/6] drm/i915: Add per client max context ban limit

[Chris Wilson]

On Wed, Nov 16, 2016 at 05:20:33PM +0200, Mika Kuoppala wrote:
> If we have a bad client submitting unfavourably across different
> contexts, creating new ones, the per context scoring of badness
> doesn't remove the root cause, the offending client.
> To counter, keep track of per client context bans. Deny access if
> client is responsible for more than 3 context bans in
> it's lifetime.
> 
> v2: move ban check to context create ioctl (Chris)
> 
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h         |  4 ++++
>  drivers/gpu/drm/i915/i915_gem.c         | 14 ++++++++++++++
>  drivers/gpu/drm/i915/i915_gem_context.c | 13 +++++++++++++
>  drivers/gpu/drm/i915/i915_gpu_error.c   | 10 ++++++----
>  4 files changed, 37 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 74f421a1..b385b9d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -411,6 +411,9 @@ struct drm_i915_file_private {
>  	} rps;
>  
>  	unsigned int bsd_engine;
> +
> +#define I915_MAX_CLIENT_CONTEXT_BANS 3

I'd just like some commentary here giving some rationale for 3.

With that,
Reviewed-by: Chris Wilson <chris at chris-wilso.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre