Re: [REGRESSION] High, likely incorrect process cpu usage counterswith kvm and 2.6.2[67]

From: Avi Kivity
Date: Mon Sep 01 2008 - 05:17:05 EST


Parag Warudkar wrote:
On Sun, Aug 31, 2008 at 11:43 AM, Avi Kivity <avi@xxxxxxxxxxxx> wrote:
Running an idle Windows VM on Linux 2.6.26+ with kvm, one sees high values
for the kvm process in top (30%-70% cpu), where one would normally expect
0%-1%. Surprisingly, the per-cpu system counters show almost 100% idle,
leading me to believe this is an accounting error and that the process does
not actually consume this much cpu.

Busted process accounting - This looks the same as
http://bugzilla.kernel.org/show_bug.cgi?id=11209 .
Please verify. Peter's patch in latest git stops showing "incorrect
looking" CPU usage but at least the process times are still wrong,
horribly.
In fact the CPU usage thing in -rc5 is likely also incorrect but I
need to analyze that bit a little more.

From Today's Git -

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND

12961 parag 20 0 83000 8908 6628 R 0 0.1 5124415h npviewer.bin


Yes, it looks very similar. In my tests, %CPU is consistent with TIME; it's just not consistent with what's actually happening and with the global statistics.


--
error compiling committee.c: too many arguments to function

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