Messages in this thread | | | Subject | Re: 2.6.4 : 100% CPU use on EIDE disk operarion, VIA chipset | From | Mikhail Ramendik <> | Date | Sun, 04 Apr 2004 23:57:55 +0400 |
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Hello,
Andreas Hartmann wrote: > > As recommended there, I have tried 2.6.5-rc3-mm4. > > > > No change. Still 100% CPU usage; the performance seems teh same. > > Yes. But it's curious: > Take a tar-file, e.g. tar the compiled 2.6 kernel directory. Than, untar > it again - the machine behaves total normaly.
Not really. I tried a "simple" tar (no gzib/bzip2) - it was the same as with cp, a near-100% CPU "system" load, most of it iowait.
If I use bzip2 with tar, then yes, the load is nearly 100% "user", actually it's bzip2. But this is because the disk i/o is done at a *far* slower rate; the bottleneck is the CPU. If we don't read (or write) the disk heavily, naturally the system/iowait load is low.
I tried doing a "cp" in another xterm window, while the tar/bzip2 was running. And sure enough, up the CPU system/iowait usage goes - the "cp"'s disk i/o takes much of the CPU time away from the bz2 task! Looks exactly like a cause of performance problems.
(All of this was done on 2.6.5-rc3-mm4).
Yours, Mikhail Ramendik
> And the 2.6-kernel is about > 23% faster than the 2.4-kernel. > > > > Yours, Mikhail Ramendik > > > > P.S. Sorry for making all comments into answers to your letter. I just > > don't want to break the thread. > > No problem - it's easier to read with comment directly in the text. > > > Regards, > Andreas Hartmann > >
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