if you suspect the scheduler then please try the following suggestions i
made in another thread:
---------->
could you run this script while such a slowdown is really prominent:
http://people.redhat.com/mingo/cfs-scheduler/tools/cfs-debug-info.sh
and send me the output it generates? The output is the most useful if
you do this on a kernel that has CONFIG_SCHED_DEBUG=y and
CONFIG_SCHEDSTATS=y enabled.
on the off chance that this issue has been fixed in the soon-to-be
2.6.25 kernel, you might also want to try x86.git/latest, which is based
on the latest Linus tree and has all relevant x86 fixes and improvements
added as well:
http://people.redhat.com/mingo/x86.git/README
several of the changes can affect performance.
a third (and most comprehensive) way to debug this would be to send me a
scheduler trace of such a slowdown, you can generate a scheduler trace
the following way:
http://people.redhat.com/mingo/sched-devel.git/readme-tracer.txt
but we can probably give a first estimation based on the cfs-debug-info
output already. Btw., you can combine the scheduler and the x86 git tree
into a temporary unified tree by doing these two commands:
git-checkout -b tmp x86/latest
git-merge sched-devel/latest
(run "make oldconfig" to pick up the new config options.)
Ingo
======
Ingo,
Thanks. I'll try this over the weekend if I get some free time, but it might not happen.
This is a busy weekend....
Rob
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