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       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


       latencytop was written by Arjan van de Ven <>.

       This  manual  page  was written by Giacomo Catenazzi <>,
       for the Debian project (but may be used by others).

                               November 9, 2008