NAME¶
latencytop - a tool for developers to visualize system latencies
SYNOPSIS¶
latencytop [
--unknown]
[
processes...
]
DESCRIPTION¶
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 hiccups.
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.
SEE ALSO¶
powertop(1)
The program is more fully described at
http://www.latencytop.org
AUTHOR¶
latencytop was written by Arjan van de Ven <arjan@linux.intel.com>.
This manual page was written by Giacomo Catenazzi <cate@debian.org>, for
the Debian project (but may be used by others).