Perfetto CLI

This section describes how to use the perfetto commandline binary to capture traces. Examples are given in terms of an Android device connected over ADB.

perfetto has two modes for configuring the tracing session (i.e. what and how to collect):

lightweight mode: all config options are supplied as commandline flags, but the available data sources are restricted to ftrace and atrace. This mode is similar to systrace.
normal mode: the configuration is specified in a protocol buffer. This allows for full customisation of collected traces.

General options

The following table lists the available options when using perfetto in either mode.

Option	Description
`--background \| -d`	Perfetto immediately exits the command-line interface and continues recording your trace in background.
`--out OUT_FILE \| -o OUT_FILE`	Specifies the desired path to the output trace file, or `-` for stdout. `perfetto` writes the output to the file described in the flags above. The output format compiles with the format defined in AOSP `trace.proto`.
`--dropbox TAG`	Uploads your trace via the DropBoxManager API using the tag you specify.
`--no-guardrails`	Disables protections against excessive resource usage when enabling the `--dropbox` flag during testing.
`--reset-guardrails`	Resets the persistent state of the guardrails and exits (for testing).
`--query`	Queries the service state and prints it as human-readable text.
`--query-raw`	Similar to `--query`, but prints raw proto-encoded bytes of `tracing_service_state.proto`.
`--help \| -h`	Prints out help text for the `perfetto` tool.

Lightweight mode

The general syntax for using perfetto in lightweight mode is as follows:

The following table lists the available options when using perfetto in lightweight mode.

Option	Description
`--time TIME[s\|m\|h] \| -t TIME[s\|m\|h]`	Specifies the trace duration in seconds, minutes, or hours. For example, `--time 1m` specifies a trace duration of 1 minute. The default duration is 10 seconds.
`--buffer SIZE[mb\|gb] \| -b SIZE[mb\|gb`]	Specifies the ring buffer size in megabytes (mb) or gigabytes (gb). The default parameter is `--buffer 32mb`.
`--size SIZE[mb\|gb] \| -s SIZE[mb\|gb]`	Specifies the max file size in megabytes (mb) or gigabytes (gb). By default `perfetto` uses only in-memory ring-buffer.

This is followed by a list of event specifiers:

Event	Description
`ATRACE_CAT`	Specifies the atrace categories you want to record a trace for. For example, the following command traces Window Manager using atrace: `adb shell perfetto --out FILE wm`. To record other categories, see this list of atrace categories.
`FTRACE_GROUP/FTRACE_NAME`	Specifies the ftrace events you want to record a trace for. For example, the following command traces sched/sched_switch events: `adb shell perfetto --out FILE sched/sched_switch`

Normal mode

The general syntax for using perfetto in normal mode is as follows:

The following table lists the available options when using perfetto in normal mode.

Option	Description
`--config CONFIG_FILE \| -c CONFIG_FILE`	Specifies the path to a configuration file. In normal mode, some configurations may be encoded in a configuration protocol buffer. This file must comply with the protocol buffer schema defined in AOSP `trace_config.proto`. You select and configure the data sources using the DataSourceConfig member of the TraceConfig, as defined in AOSP `data_source_config.proto`.
`--txt`	Instructs `perfetto` to parse the config file as pbtxt. This flag is experimental, and it's not recommended that you enable it for production.