Use OA interrupt

data/gputop.proto

@@ -96,8 +96,9 @@ message Features
     repeated string notices = 12;
     required int32 server_pid = 13;
     repeated string events = 14;
-    required bool has_i915_oa_cpu_timestamps = 15;
-    required bool has_i915_oa_gpu_timestamps = 16;
+    required bool has_i915_oa_interrupt = 15;
+    required bool has_i915_oa_cpu_timestamps = 16;
+    required bool has_i915_oa_gpu_timestamps = 17;
 }
 
 message ProcessInfo
@@ -185,10 +186,12 @@ message OAStreamInfo
     required uint32 period_exponent = 3;
     //TODO: allow specifying a specific context to profile
     required bool per_ctx_mode = 4;
+    // Use OA interrupt
+    required bool interrupt = 5;
     // Adds GPU timestamps in the i915 perf reports
-    required bool gpu_timestamps = 5;
+    required bool gpu_timestamps = 6;
     // Adds CPU timestamps in the i915 perf reports
-    required bool cpu_timestamps = 6;
+    required bool cpu_timestamps = 7;
 }
 
 message TracepointConfig

lib/gputop-client-context.c

@@ -1241,6 +1241,7 @@ open_i915_perf_stream(struct gputop_client_context *ctx)
     oa_stream.period_exponent =
         gputop_time_to_oa_exponent(&ctx->devinfo, ctx->oa_sampling_period_ns);
     oa_stream.per_ctx_mode = false;
+    oa_stream.interrupt = ctx->i915_perf_config.oa_interrupt;
     oa_stream.cpu_timestamps = ctx->i915_perf_config.cpu_timestamps;
     oa_stream.gpu_timestamps = ctx->i915_perf_config.gpu_timestamps;
 
@@ -1485,6 +1486,8 @@ handle_protobuf_message(struct gputop_client_context *ctx,
             gputop__message__free_unpacked(ctx->features, NULL);
         ctx->features = message;
         register_platform_metrics(ctx, message->features->devinfo);
+        ctx->i915_perf_config.oa_interrupt =
+            message->features->has_i915_oa_interrupt;
         ctx->i915_perf_config.cpu_timestamps =
             message->features->has_i915_oa_cpu_timestamps &&
           message->features->has_i915_oa_gpu_timestamps;

lib/gputop-oa-counters.h

@@ -154,6 +154,7 @@ gputop_cc_oa_report_get_reason(const struct gputop_devinfo *devinfo,
 
 struct gputop_i915_perf_configuration {
     bool oa_reports;
+    bool oa_interrupt;
     bool cpu_timestamps;
     bool gpu_timestamps;
 };

mesa/include/drm-uapi/i915_drm.h

@@ -1510,6 +1510,37 @@ enum drm_i915_perf_property_id {
 	 */
 	DRM_I915_PERF_PROP_OA_EXPONENT,
 
+	/**
+	 * Specifying this property sets up a hrtimer in nanoseconds at which
+	 * the i915 driver will check the OA buffer for available data. A
+	 * value of 0 means no hrtimer will be started. Values below 100
+	 * microseconds are not allowed.
+	 */
+	DRM_I915_PERF_PROP_POLL_OA_DELAY,
+
+	/**
+	 * Specifying this property sets up the interrupt mechanism for the OA
+	 * buffer in i915. This option in conjuction with a long polling delay
+	 * for avaibility of OA data can reduce CPU load significantly if you
+	 * do not care about OA data being read as soon as it's available.
+	 */
+	DRM_I915_PERF_PROP_OA_ENABLE_INTERRUPT,
+
+	/**
+	 * Specify a global OA buffer size to be allocated in bytes. The size
+	 * specified must be supported by HW (currently supported sizes are
+	 * powers of 2 ranging from 128Kb to 16Mb).
+	 */
+	DRM_I915_PERF_PROP_OA_BUFFER_SIZE,
+
+	/**
+	 * Specifying this property is only valid when specify a context to
+	 * filter with DRM_I915_PERF_PROP_CTX_HANDLE. Specifying this property
+	 * will hold preemption of the particular context we want to gather
+	 * performance data about.
+	 */
+	DRM_I915_PERF_PROP_HOLD_PREEMPTION,
+
 	/**
 	 * The value of this property set to 1 requests inclusion of GPU
 	 * timestamp in the perf sample data.

server/gputop-perf.c

@@ -241,6 +241,13 @@ kernel_supports_open_property(uint64_t prop, uint64_t value)
 
 }
 
+bool
+gputop_perf_kernel_has_i915_oa_interrupt(void)
+{
+    return kernel_supports_open_property(DRM_I915_PERF_PROP_OA_ENABLE_INTERRUPT,
+                                         true);
+}
+
 bool
 gputop_perf_kernel_has_i915_oa_cpu_timestamps(void)
 {
@@ -462,6 +469,7 @@ struct gputop_perf_stream *
 gputop_open_i915_perf_oa_stream(struct gputop_metric_set *metric_set,
 				int period_exponent,
 				struct ctx_handle *ctx,
+                                bool interrupt,
                                 bool cpu_timestamps,
                                 bool gpu_timestamps,
                                 void (*ready_cb)(struct gputop_perf_stream *),
@@ -511,6 +519,11 @@ gputop_open_i915_perf_oa_stream(struct gputop_metric_set *metric_set,
 		ctx->fd, ctx->id);
 	}
 
+        if (interrupt) {
+            properties[p++] = DRM_I915_PERF_PROP_OA_ENABLE_INTERRUPT;
+            properties[p++] = true;
+        }
+
         if (cpu_timestamps) {
             properties[p++] = DRM_I915_PERF_PROP_SAMPLE_SYSTEM_TS;
             properties[p++] = true;
@@ -538,6 +551,7 @@ gputop_open_i915_perf_oa_stream(struct gputop_metric_set *metric_set,
     stream->metric_set = metric_set;
     stream->ready_cb = ready_cb;
     stream->per_ctx_mode = ctx != NULL;
+    stream->oa.interrupt_enabled = interrupt;
 
     stream->fd = stream_fd;
 

server/gputop-perf.h

@@ -155,6 +155,7 @@ struct gputop_perf_stream
             uint8_t *last;
             int last_buf_idx;
 
+            bool interrupt_enabled;
             bool header_written;
             uint32_t total_len;
         } oa;
@@ -240,6 +241,7 @@ struct gputop_perf_stream *
 gputop_open_i915_perf_oa_stream(struct gputop_metric_set *metric_set,
                                 int period_exponent,
                                 struct ctx_handle *ctx,
+                                bool interrupt,
                                 bool cpu_timestamps,
                                 bool gpu_timestamps,
                                 void (*ready_cb)(struct gputop_perf_stream *),
@@ -288,5 +290,6 @@ void gputop_perf_stream_unref(struct gputop_perf_stream *stream);
 
 const struct gputop_devinfo *gputop_perf_get_devinfo(void);
 
+bool gputop_perf_kernel_has_i915_oa_interrupt(void);
 bool gputop_perf_kernel_has_i915_oa_cpu_timestamps(void);
 bool gputop_perf_kernel_has_i915_oa_gpu_timestamps(void);

server/gputop-server.c

@@ -613,6 +613,7 @@ handle_open_i915_perf_oa_stream(h2o_websocket_conn_t *conn,
     stream = gputop_open_i915_perf_oa_stream(metric_set,
                                              oa_stream_info->period_exponent,
                                              ctx,
+                                             oa_stream_info->interrupt,
                                              oa_stream_info->cpu_timestamps,
                                              oa_stream_info->gpu_timestamps,
                                              (open_stream->live_updates ?
@@ -1146,6 +1147,7 @@ handle_get_features(h2o_websocket_conn_t *conn,
     pb_devinfo.topology = &pb_topology;
 
     pb_features.fake_mode = gputop_fake_mode;
+    pb_features.has_i915_oa_interrupt = gputop_perf_kernel_has_i915_oa_interrupt();
     pb_features.has_i915_oa_cpu_timestamps = gputop_perf_kernel_has_i915_oa_cpu_timestamps();
     pb_features.has_i915_oa_gpu_timestamps = gputop_perf_kernel_has_i915_oa_gpu_timestamps();