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

Andreas Baer
2005-07-25T21:49:02Z

Bill Davidsen wrote:
>
> 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.

I don't know what exactly produces this _llseek calls, but I ran the compiled
binaries on both machines (desktop + notebook) without any recompilation and so
I think they should do the same (even if this is bad or not optimized), but I
see a time difference of more than 2:30 :) This _llseek calls also don't seem
to be faster or slower if you compare the times on the notebook and the desktop.

>> 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>
>
>