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):

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:

 adb shell perfetto [ --time TIMESPEC ] [ --buffer SIZE ] [ --size SIZE ]
           [ ATRACE_CAT | FTRACE_GROUP/FTRACE_NAME | FTRACE_GROUP/* ]...

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
FTRACE_GROUP/* Record all events in group (e.g. sched/*). Specifies the group of ftrace events you want to record a trace for. For example, the following command traces sched/* events: adb shell perfetto --out FILE 'sched/*'

Normal mode

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

 adb shell perfetto [ --txt ] --config CONFIG_FILE

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.