[Intel-gfx] [PATCH 09/16] drm/i915: Simplify releasing context reference

[Tvrtko Ursulin]

On 07/12/2016 13:58, Chris Wilson wrote:
> A few users only take the struct_mutex in order to release a reference
> to a context. We can expose a kref_put_mutex() wrapper in order to
> simplify these users, and optimise taking of the mutex to the final
> unref.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_drv.h  |  7 +++++++
>  drivers/gpu/drm/i915/i915_perf.c | 16 ++++------------
>  2 files changed, 11 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 7c228622716a..3411e38e32af 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -3320,6 +3320,13 @@ static inline void i915_gem_context_put(struct i915_gem_context *ctx)
>  	kref_put(&ctx->ref, i915_gem_context_free);
>  }
>
> +static inline void i915_gem_context_put_unlocked(struct i915_gem_context *ctx)
> +{
> +	kref_put_mutex(&ctx->ref,
> +		       i915_gem_context_free,
> +		       &ctx->i915->drm.struct_mutex);
> +}
> +
>  static inline struct intel_timeline *
>  i915_gem_context_lookup_timeline(struct i915_gem_context *ctx,
>  				 struct intel_engine_cs *engine)
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index cfe4152212b9..ee6271fe96de 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -1298,8 +1298,6 @@ static long i915_perf_ioctl(struct file *file,
>
>  static void i915_perf_destroy_locked(struct i915_perf_stream *stream)
>  {
> -	struct drm_i915_private *dev_priv = stream->dev_priv;
> -
>  	if (stream->enabled)
>  		i915_perf_disable_locked(stream);
>
> @@ -1308,11 +1306,8 @@ static void i915_perf_destroy_locked(struct i915_perf_stream *stream)
>
>  	list_del(&stream->link);
>
> -	if (stream->ctx) {
> -		mutex_lock(&dev_priv->drm.struct_mutex);
> -		i915_gem_context_put(stream->ctx);
> -		mutex_unlock(&dev_priv->drm.struct_mutex);
> -	}
> +	if (stream->ctx)
> +		i915_gem_context_put_unlocked(stream->ctx);
>
>  	kfree(stream);
>  }
> @@ -1446,11 +1441,8 @@ i915_perf_open_ioctl_locked(struct drm_i915_private *dev_priv,
>  err_alloc:
>  	kfree(stream);
>  err_ctx:
> -	if (specific_ctx) {
> -		mutex_lock(&dev_priv->drm.struct_mutex);
> -		i915_gem_context_put(specific_ctx);
> -		mutex_unlock(&dev_priv->drm.struct_mutex);
> -	}
> +	if (specific_ctx)
> +		i915_gem_context_put_unlocked(specific_ctx);
>  err:
>  	return ret;
>  }
>

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko