[igt-dev] [PATCH 3/3] tools: Allow user to set poll delay in i915 perf recorder

[Dixit, Ashutosh]

On Wed, 25 Mar 2020 14:50:05 -0700, Umesh Nerlige Ramappa wrote:
>
> Add poll delay parameter to the i915-perf-recorder tool so that the user
> can set the frequency of the poll timer that checks for available
> reports in the OA buffer.
>
> v2:
> - Change poll period parameter type to match kernel interface (Lionel)
> - Update to use poll period in the code (Ashutosh)
>
> v3:
> - Change command line paramter to poll-period (Ashutosh)
> - Fix the version check for the feature (Ashutosh)
>
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

Reviewed-by: Ashutosh Dixit <ashutosh.dixit at intel.com>



> ---
>  tools/i915-perf/i915_perf_recorder.c | 38 +++++++++++++++++++++++++---
>  1 file changed, 35 insertions(+), 3 deletions(-)
>
> diff --git a/tools/i915-perf/i915_perf_recorder.c b/tools/i915-perf/i915_perf_recorder.c
> index 6bbc451e..4d729b0e 100644
> --- a/tools/i915-perf/i915_perf_recorder.c
> +++ b/tools/i915-perf/i915_perf_recorder.c
> @@ -353,14 +353,31 @@ struct recording_context {
>
>	const char *command_fifo;
>	int command_fifo_fd;
> +
> +	uint64_t poll_period;
>  };
>
> +static int
> +perf_revision(int drm_fd)
> +{
> +	drm_i915_getparam_t gp;
> +	int value = 1;
> +
> +	gp.param = I915_PARAM_PERF_REVISION;
> +	gp.value = &value;
> +	perf_ioctl(drm_fd, DRM_IOCTL_I915_GETPARAM, &gp);
> +
> +	return value;
> +}
> +
>  static int
>  perf_open(struct recording_context *ctx)
>  {
>	uint64_t properties[DRM_I915_PERF_PROP_MAX * 2];
>	struct drm_i915_perf_open_param param;
> -	int p = 0, stream_fd;
> +	int p = 0, stream_fd, revision;
> +
> +	revision = perf_revision(ctx->drm_fd);
>
>	properties[p++] = DRM_I915_PERF_PROP_SAMPLE_OA;
>	properties[p++] = true;
> @@ -374,6 +391,11 @@ perf_open(struct recording_context *ctx)
>	properties[p++] = DRM_I915_PERF_PROP_OA_EXPONENT;
>	properties[p++] = ctx->oa_exponent;
>
> +	if (revision >= 5) {
> +		properties[p++] = DRM_I915_PERF_PROP_POLL_OA_PERIOD;
> +		properties[p++] = ctx->poll_period;
> +	}
> +
>	memset(&param, 0, sizeof(param));
>	param.flags = 0;
>	param.flags |= I915_PERF_FLAG_FD_CLOEXEC | I915_PERF_FLAG_FD_NONBLOCK;
> @@ -720,7 +742,10 @@ usage(const char *name)
>		"                                       (To use with i915-perf-control)\n"
>		"     --output,             -o <path>   Output file (default = i915_perf.record)\n"
>		"     --cpu-clock,          -k <path>   Cpu clock to use for correlations\n"
> -		"                                       Values: boot, mono, mono_raw (default = mono)\n",
> +		"                                       Values: boot, mono, mono_raw (default = mono)\n"
> +		"     --poll-period         -P <value>  Polling interval in microseconds used by a timer in the driver to query\n"
> +		"                                       for OA reports periodically\n"
> +		"                                       (default = 5000), Minimum = 100.\n",
>		name);
>  }
>
> @@ -762,6 +787,7 @@ main(int argc, char *argv[])
>		{"size",                 required_argument, 0, 's'},
>		{"command-fifo",         required_argument, 0, 'f'},
>		{"cpu-clock",            required_argument, 0, 'k'},
> +		{"poll-period",          required_argument, 0, 'P'},
>		{0, 0, 0, 0}
>	};
>	const struct {
> @@ -788,9 +814,12 @@ main(int argc, char *argv[])
>
>		.command_fifo = I915_PERF_RECORD_FIFO_PATH,
>		.command_fifo_fd = -1,
> +
> +		/* 5 ms poll period */
> +		.poll_period = 5 * 1000 * 1000,
>	};
>
> -	while ((opt = getopt_long(argc, argv, "hc:p:m:Co:s:f:k:", long_options, NULL)) != -1) {
> +	while ((opt = getopt_long(argc, argv, "hc:p:m:Co:s:f:k:P:", long_options, NULL)) != -1) {
>		switch (opt) {
>		case 'h':
>			usage(argv[0]);
> @@ -832,6 +861,9 @@ main(int argc, char *argv[])
>			}
>			break;
>		}
> +		case 'P':
> +			ctx.poll_period = MAX(100, atol(optarg)) * 1000;
> +			break;
>		default:
>			fprintf(stderr, "Internal error: "
>				"unexpected getopt value: %d\n", opt);
> --
> 2.20.1
>