Re: Problem with Asus P4C800-DX and P4 -Northwood-

From: Bill Davidsen
Date: Mon Jul 25 2005 - 15:45:40 EST



One other oddment about this motherboard, Forgive if I have over-snipped this trying to make it relevant...

Andreas Baer wrote:

Willy Tarreau wrote:

On Mon, Jul 25, 2005 at 03:10:08PM +0200, Andreas Baer wrote:

There clearly is a problem on the system installed on this machine. You should
use strace to see what this machine does all the time, it is absolutely not
expected that the user/system ratios change so much between two nearly
identical systems. So there are system calls which eat all CPU. You may want
to try strace -Tttt on the running process during a few tens of seconds. I
guess you'll immediately find the culprit amongst the syscalls, and it might
give you a clue.


I hope you are talking about a hardware/kernel problem and not a software
problem, because I tried it also with LiveCD's and they showed the same results
on this machine.
I'm not a linux expert, that means I've never done anything like that before,
so it would be nice if you give me a hint what you see in this results. :)


Am I misreading this, or is your program doing a bunch of seeks not followed by an i/o operation? I would doubt that's important, but your vmstat showed a lot of system time, and I just wonder if llseek() is more expensive in Linux than Windows. Or if your code is such that these calls are not optimized away by gcc.

strace output for desktop:
<--snip-->

[pid 1431] 1122318636.262578 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000017>
[pid 1431] 1122318636.262654 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000017>
[pid 1431] 1122318636.262732 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000017>
[pid 1431] 1122318636.262809 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.262881 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.262952 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263023 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263094 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.263165 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263237 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.263310 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263381 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263452 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263523 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.263594 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263666 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000017>
[pid 1431] 1122318636.263740 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000024>
[pid 1431] 1122318636.263841 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263913 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.263984 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000014>
[pid 1431] 1122318636.264055 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.264127 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.264199 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.264271 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.264342 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.264414 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.264487 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.264558 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.264630 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.264710 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.264788 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.264861 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.264934 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.265006 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.265077 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.265149 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000014>
[pid 1431] 1122318636.265220 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.265292 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.265363 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.265436 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.265509 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.265580 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.265652 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.265726 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000017>
[pid 1431] 1122318636.265818 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.265891 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.265963 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.266034 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.266106 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.266177 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.266250 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>
[pid 1431] 1122318636.266322 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.266394 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000015>
[pid 1431] 1122318636.266466 _llseek(3, 1761280, [1761280], SEEK_SET) = 0 <0.000016>

--
-bill davidsen (davidsen@xxxxxxx)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me
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