[Intel-gfx] [PATCH] drm/i915/perf: Set the exclusive stream under perf->lock

[Lionel Landwerlin]

On 07/10/2019 16:38, Chris Wilson wrote:
> The BKL struct_mutex is no more, the only serialisation we required for
> setting the exclusive stream is already managed by ce->pin_mutex in
> gen8_configure_all_contexts(). As such, we can manipulate
> i915_perf.exclusive_stream underneath our own perf->lock.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

Long time coming:


Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

> ---
>   drivers/gpu/drm/i915/i915_perf.c | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index ef5e48ebaaa6..45167c595322 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -1343,10 +1343,10 @@ static void i915_oa_stream_destroy(struct i915_perf_stream *stream)
>   	 * Unset exclusive_stream first, it will be checked while disabling
>   	 * the metric set on gen8+.
>   	 */
> -	mutex_lock(&perf->i915->drm.struct_mutex);
> +	mutex_lock(&perf->lock);
>   	perf->exclusive_stream = NULL;
>   	perf->ops.disable_metric_set(stream);
> -	mutex_unlock(&perf->i915->drm.struct_mutex);
> +	mutex_unlock(&perf->lock);
>   
>   	free_oa_buffer(stream);
>   
> @@ -1853,7 +1853,7 @@ static int gen8_configure_all_contexts(struct i915_perf_stream *stream,
>   	for (i = 2; i < ARRAY_SIZE(regs); i++)
>   		regs[i].value = oa_config_flex_reg(oa_config, regs[i].reg);
>   
> -	lockdep_assert_held(&i915->drm.struct_mutex);
> +	lockdep_assert_held(&stream->perf->lock);
>   
>   	/*
>   	 * The OA register config is setup through the context image. This image
> @@ -2220,7 +2220,7 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
>   	if (ret)
>   		goto err_oa_buf_alloc;
>   
> -	ret = i915_mutex_lock_interruptible(&stream->gt->i915->drm);
> +	ret = mutex_lock_interruptible(&perf->lock);
>   	if (ret)
>   		goto err_lock;
>   
> @@ -2233,7 +2233,7 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
>   		goto err_enable;
>   	}
>   
> -	mutex_unlock(&stream->gt->i915->drm.struct_mutex);
> +	mutex_unlock(&perf->lock);
>   
>   	hrtimer_init(&stream->poll_check_timer,
>   		     CLOCK_MONOTONIC, HRTIMER_MODE_REL);
> @@ -2246,7 +2246,7 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
>   err_enable:
>   	perf->exclusive_stream = NULL;
>   	perf->ops.disable_metric_set(stream);
> -	mutex_unlock(&stream->gt->i915->drm.struct_mutex);
> +	mutex_unlock(&perf->lock);
>   
>   err_lock:
>   	free_oa_buffer(stream);