protos/perfetto/trace/ftrace/ftrace_stats.proto

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

syntax = "proto2";

package perfetto.protos;

// Per-CPU stats for the ftrace data source gathered from the kernel from
// /sys/kernel/debug/tracing/per_cpu/cpuX/stats.
message FtraceCpuStats {
  // CPU index.
  optional uint64 cpu = 1;

  // Number of entries still in the kernel buffer. Ideally this should be close
  // to zero, as events are consumed regularly and moved into the userspace
  // buffers (or file).
  optional uint64 entries = 2;

  // Number of events lost in kernel buffers due to overwriting of old events
  // before userspace had a chance to drain them.
  optional uint64 overrun = 3;

  // This should always be zero. If not the buffer size is way too small or
  // something went wrong with the tracer.
  optional uint64 commit_overrun = 4;

  // Bytes actually read (not overwritten).
  optional uint64 bytes_read = 5;

  // The timestamp for the oldest event still in the ring buffer.
  optional double oldest_event_ts = 6;

  // The current timestamp.
  optional double now_ts = 7;

  // If the kernel buffer has overwrite mode disabled, this will show the number
  // of new events that were lost because the buffer was full. This is similar
  // to |overrun| but only for the overwrite=false case.
  optional uint64 dropped_events = 8;

  // The number of events read.
  optional uint64 read_events = 9;
}

// Ftrace stats for all CPUs.
message FtraceStats {
  enum Phase {
    UNSPECIFIED = 0;
    START_OF_TRACE = 1;
    END_OF_TRACE = 2;
  }

  // Tells when stats were sampled. There should be one sample at the beginning
  // of the trace and one sample at the end.
  optional Phase phase = 1;

  // Per-CPU stats (one entry for each CPU).
  repeated FtraceCpuStats cpu_stats = 2;
}