protos/perfetto/config/ftrace/ftrace_config.proto

/*
 * Copyright (C) 2017 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;

message FtraceConfig {
  repeated string ftrace_events = 1;
  repeated string atrace_categories = 2;
  repeated string atrace_apps = 3;
  // *Per-CPU* buffer size.
  optional uint32 buffer_size_kb = 10;
  optional uint32 drain_period_ms = 11;

  // Configuration for compact encoding of scheduler events. When enabled (and
  // recording the relevant ftrace events), specific high-volume events are
  // encoded in a denser format than normal.
  message CompactSchedConfig {
    // If true, and sched_switch or sched_waking ftrace events are enabled,
    // record those events in the compact format.
    optional bool enabled = 1;
  }
  optional CompactSchedConfig compact_sched = 12;

  // Enables symbol name resolution against /proc/kallsyms.
  // It requires that either traced_probes is running as root or that
  // kptr_restrict has been manually lowered.
  // It does not disclose KASLR, symbol addresses are mangled.
  optional bool symbolize_ksyms = 13;

  // By default the kernel symbolizer is lazily initialized on a deferred task
  // to reduce ftrace's time-to-start-recording. Unfortunately that makes
  // ksyms integration tests hard. This flag forces the kernel symbolizer to be
  // initialized synchronously on the data source start and hence avoiding
  // timing races in tests.
  optional bool initialize_ksyms_synchronously_for_testing = 14;

  // When this boolean is true AND the ftrace_events contains "kmem/rss_stat",
  // this option causes traced_probes to enable the "kmem/rss_stat_throttled"
  // event instad if present, and fall back to "kmem/rss_stat" if not present.
  // The historical context for this is the following:
  // - Up to Android S (12), the rss_stat was internally throttled in its
  //   kernel implementation.
  // - A change introduced in the kernels after S has introduced a new
  //   "rss_stat_throttled" making the original "rss_stat" event unthrottled
  //   (hence very spammy).
  // - Not all Android T/13 devices will receive a new kernel though, hence we
  //   need to deal with both cases.
  // For more context: go/rss-stat-throttled.
  // TODO(kaleshsingh): implement the logic behind this. Right now this flag
  // does nothing.
  optional bool throttle_rss_stat = 15;

  // If true, avoid enabling events that aren't statically known by
  // traced_probes. Otherwise, the default is to emit such events as
  // GenericFtraceEvent protos.
  // Prefer to keep this flag at its default. This was added for Android
  // tracing, where atrace categories and/or atrace HAL requested events can
  // expand to events that aren't of interest to the tracing user.
  // Introduced in: Android T.
  optional bool disable_generic_events = 16;
}