System calls

On Linux and Android (userdebug builds only) Perfetto can keep track of system calls.

Right now only the syscall number is recorded in the trace, the arguments are not stored to limit the trace size overhead.

At import time, the Trace Processor uses an internal syscall mapping table, currently supporting x86, x86_64, ArmEabi, aarch32 and aarch64. These tables are generated through the extract_linux_syscall_tables script.


At the UI level system calls are shown inlined with the per-thread slice tracks:


At the SQL level, syscalls are no different than any other userspace slice event. They get interleaved in the per-thread slice stack and can be easily filtered by looking for the 'sys_' prefix:

select ts, dur, as thread,, depth from slices as s left join thread_track as tt on s.track_id = left join thread as t on tt.utid = t.utid where like 'sys_%'
ts dur thread name
856325324372751 439867648 s.nexuslauncher sys_epoll_pwait
856325324376970 990 FpsThrottlerThr sys_recvfrom
856325324378376 2657 surfaceflinger sys_ioctl
856325324419574 1250 android.anim.lf sys_recvfrom
856325324428168 27344 android.anim.lf sys_ioctl
856325324451345 573 FpsThrottlerThr sys_getuid


data_sources: { config { name: "linux.ftrace" ftrace_config { ftrace_events: "raw_syscalls/sys_enter" ftrace_events: "raw_syscalls/sys_exit" } } }