Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
19 lines
1010 B
Plaintext
19 lines
1010 B
Plaintext
The **rtla timerlat** tool is an interface for the *timerlat* tracer. The
|
|
*timerlat* tracer dispatches a kernel thread per-cpu. These threads
|
|
set a periodic timer to wake themselves up and go back to sleep. After
|
|
the wakeup, they collect and generate useful information for the
|
|
debugging of operating system timer latency.
|
|
|
|
The *timerlat* tracer outputs information in two ways. It periodically
|
|
prints the timer latency at the timer *IRQ* handler and the *Thread*
|
|
handler. It also enables the trace of the most relevant information via
|
|
**osnoise:** tracepoints.
|
|
|
|
The **rtla timerlat** tool sets the options of the *timerlat* tracer
|
|
and collects and displays a summary of the results. By default,
|
|
the collection is done synchronously in kernel space using a dedicated
|
|
BPF program attached to the *timerlat* tracer. If either BPF or
|
|
the **osnoise:timerlat_sample** tracepoint it attaches to is
|
|
unavailable, the **rtla timerlat** tool falls back to using tracefs to
|
|
process the data asynchronously in user space.
|