Commit 7831e9a9 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/perf: Allow dynamic reconfiguration of the OA stream 

Introduce a new perf_ioctl command to change the OA configuration of the
active stream. This allows the OA stream to be reconfigured between
batch buffers, giving greater flexibility in sampling. We inject a
request into the OA context to reconfigure the stream asynchronously on
the GPU in between and ordered with execbuffer calls.

Original patch for dynamic reconfiguration by Lionel Landwerlin.

Link: https://gitlab.freedesktop.org/mesa/mesa/merge_requests/932


Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarLionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191014201404.22468-3-chris@chris-wilson.co.uk
parent 4f6ccc74

drivers/gpu/drm/i915/i915_perf.c

+45 −1
Original line number Diff line number Diff line
@@ -2862,6 +2862,40 @@ static void i915_perf_disable_locked(struct i915_perf_stream *stream) 
		stream->ops->disable(stream);

}



static long i915_perf_config_locked(struct i915_perf_stream *stream,

				    unsigned long metrics_set)

{

	struct i915_oa_config *config;

	long ret = stream->oa_config->id;



	config = i915_perf_get_oa_config(stream->perf, metrics_set);

	if (!config)

		return -EINVAL;



	if (config != stream->oa_config) {

		int err;



		/*

		 * If OA is bound to a specific context, emit the

		 * reconfiguration inline from that context. The update

		 * will then be ordered with respect to submission on that

		 * context.

		 *

		 * When set globally, we use a low priority kernel context,

		 * so it will effectively take effect when idle.

		 */

		err = emit_oa_config(stream, oa_context(stream));

		if (err == 0)

			config = xchg(&stream->oa_config, config);

		else

			ret = err;

	}



	i915_oa_config_put(config);



	return ret;

}



/**

 * i915_perf_ioctl - support ioctl() usage with i915 perf stream FDs

 * @stream: An i915 perf stream
@@ -2885,6 +2919,8 @@ static long i915_perf_ioctl_locked(struct i915_perf_stream *stream, 
	case I915_PERF_IOCTL_DISABLE:

		i915_perf_disable_locked(stream);

		return 0;

	case I915_PERF_IOCTL_CONFIG:

		return i915_perf_config_locked(stream, arg);

	}



	return -EINVAL;
@@ -4023,7 +4059,15 @@ void i915_perf_fini(struct drm_i915_private *i915) 
 */

int i915_perf_ioctl_version(void)

{

	return 1;

	/*

	 * 1: Initial version

	 *   I915_PERF_IOCTL_ENABLE

	 *   I915_PERF_IOCTL_DISABLE

	 *

	 * 2: Added runtime modification of OA config.

	 *   I915_PERF_IOCTL_CONFIG

	 */

	return 2;

}



#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)

include/uapi/drm/i915_drm.h

+13 −0
Original line number Diff line number Diff line
@@ -1932,6 +1932,19 @@ struct drm_i915_perf_open_param { 
 */

#define I915_PERF_IOCTL_DISABLE	_IO('i', 0x1)



/**

 * Change metrics_set captured by a stream.

 *

 * If the stream is bound to a specific context, the configuration change

 * will performed inline with that context such that it takes effect before

 * the next execbuf submission.

 *

 * Returns the previously bound metrics set id, or a negative error code.

 *

 * This ioctl is available in perf revision 2.

 */

#define I915_PERF_IOCTL_CONFIG	_IO('i', 0x2)



/**

 * Common to all i915 perf records

 */

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