latencytop - a tool for developers to visualize system latencies
latencytop [--unknown] [processes...]
This manual page documents briefly the latencytop command.
latencytop is a Linux* tool for software developers (both kernel and
userspace), aimed at identifying where in the system latency is
happening, and what kind of operation/action is causing the latency to
happen so that the code can be changed to avoid the worst latency
LatencyTOP focuses on the cases where the applications want to run and
execute useful code, but there’s some resource that’s not currently
available (and the kernel then blocks the process). This is done both
on a system level and on a per process level, so that you can see
what’s happening to the system, and which process is suffering and/or
causing the delays.
You can walk the processes by using the cursor keys. If you press s
followed by a letter, then only active processes starting with that
lettter are displayed and walked. If you press s followed by 0 then
that filter is reset.
If you press f then LatencyTop displays a list of all processes
currently waiting for an fsync to finish. Pressing f again returns you
to the normal operating mode of LatencyTop.
The program is more fully described at http://www.latencytop.org
latencytop was written by Arjan van de Ven <email@example.com>.
This manual page was written by Giacomo Catenazzi <firstname.lastname@example.org>,
for the Debian project (but may be used by others).
November 9, 2008