Re: "sched: add vslice" causes horrible interactivity under load

From: Ingo Molnar
Date: Sun Jan 27 2008 - 17:14:51 EST



* Benjamin K. Stuhl <benjamin.stuhl@xxxxxxxxxxxx> wrote:

> I recently upgraded from 2.6.23.x to 2.6.24 and found that whereas
> with 2.6.23.x I could have multiple "make -j3" compilation runs going
> in the background with no real problems (on a dual-core Core 2), with
> 2.6.24 I get multiple-second lags when trying to switch tasks in KDE.

that sounds bad ... Could you send me the output of:

http://people.redhat.com/mingo/cfs-scheduler/tools/cfs-debug-info.sh

while such delays are happening? Please enable CONFIG_SCHED_DEBUG=y and
CONFIG_SCHEDSTATS=y as well before doing the dump. Also please send your
.config.

to get best output from cfs-debug-info.sh, please first run this:

http://people.redhat.com/mingo/cfs-scheduler/tools/cfs-debug-info-clear.sh

then reproduce the delay, and then run cfs-debug-info.sh to capture all
that task stats.

Ingo
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