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RE: [linuxperf] system time on SMP



Yes, I do:

It's exclusively apache (httpd) and mysql. The numbers of processes
depending on the number of requests I am trying to simulate. I can verify
this using ps -aux and sort for processor usage. Below the output(s) for
iostat, vmstat and top.

Again, any and all suggestions are welcome. Maybe it's just the algorithm,
the strange thing is, though, that on a one processor machine, I see much
less (~20%) of system time being used.

Does anybody know how I can 'switch off' processors, so that I can run tests
with less processors on the same machine?

============================================================================
=======

iostat gives me (yes, only one disk):
Device:        tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
dev8-0        0.80         0.00        76.80          0        384
Device:        tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
dev8-0        0.60         0.00        44.80          0        224


vmstat shows (every 5 seconds) ... here you can see as well the system time
that's being used ...

   procs                      memory    swap          io     system
cpu
 r  b  w   swpd   free   buff  cache  si  so    bi    bo   in    cs  us  sy
id
26  0  0      0 1399652  57420 370660   0   0     0    11  540 32086  48  52
0
31  0  0      0 1399112  57420 370768   0   0     0    22  574 32251  52  48
0
24  0  0      0 1398848  57420 370892   0   0     0    26  526 32221  53  47
0
17  0  0      0 1399556  57420 371036   0   0     0    28  611 30885  57  43
0
17  0  0      0 1392096  57420 371136   0   0     0    20  589 32572  49  51
0
43  0  0      0 1376984  57420 371216   0   0     0    25  513 30822  47  53
0
42  0  0      0 1380476  57420 371328   0   0     0    26  509 29768  53  47
0
33  0  0      0 1384124  57420 371472   0   0     0    24  644 30573  52  48
0
36  0  0      0 1383572  57420 371564   0   0     0    23  463 31736  47  53
0
28  0  0      0 1383868  57420 371696   0   0     0    30  523 31080  49  51
0
30  0  0      0 1383368  57420 371832   0   0     0    26  610 29638  55  45
0


This is what 'top' looks like:
======================================================================
  6:17pm  up 48 days,  7:58,  2 users,  load average: 40.78, 25.29, 14.78
181 processes: 127 sleeping, 54 running, 0 zombie, 0 stopped
CPU0 states: 51.2% user, 48.4% system,  0.0% nice,  0.0% idle
CPU1 states: 48.5% user, 51.0% system,  0.0% nice,  0.0% idle
CPU2 states: 54.2% user, 45.3% system,  0.0% nice,  0.0% idle
CPU3 states: 50.1% user, 50.0% system,  0.0% nice,  0.0% idle
CPU4 states: 48.1% user, 51.5% system,  0.0% nice,  0.0% idle
CPU5 states: 46.1% user, 53.5% system,  0.0% nice,  0.0% idle
CPU6 states: 45.0% user, 55.0% system,  0.0% nice,  0.0% idle
CPU7 states: 51.0% user, 49.0% system,  0.0% nice,  0.0% idle
Mem:  2059552K av,  695436K used, 1364116K free,       0K shrd,   57424K
buff
Swap: 2088408K av,       0K used, 2088408K free                  375352K
cached

  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
25601 mysql     20   0 18620  18M  1724 R    16.1  0.9   0:01 mysqld
25589 mysql     20   0 18584  18M  1724 R    15.1  0.9   0:01 mysqld
25337 mysql     20   0 18584  18M  1724 R    15.0  0.9   0:04 mysqld
25587 mysql     20   0 18584  18M  1724 R    15.0  0.9   0:01 mysqld
25602 mysql     20   0 18588  18M  1724 R    14.8  0.9   0:01 mysqld
25474 mysql     20   0 18584  18M  1724 R    14.4  0.9   0:02 mysqld
25582 mysql     19   0 18584  18M  1724 R    14.2  0.9   0:01 mysqld
25593 mysql     19   0 18620  18M  1724 R    14.2  0.9   0:01 mysqld
25604 mysql     19   0 18588  18M  1724 R    14.2  0.9   0:01 mysqld
25514 mysql     20   0 18584  18M  1724 R    14.1  0.9   0:02 mysqld
25591 mysql     20   0 18588  18M  1724 R    13.9  0.9   0:01 mysqld
==========================================================================

-----Original Message-----
From: owner-linuxperf@nl.linux.org
[mailto:owner-linuxperf@nl.linux.org]On Behalf Of Thomas D. Barringer
Sent: Tuesday, August 21, 2001 5:24 AM
To: linuxperf@nl.linux.org
Subject: RE: [linuxperf] system time on SMP


Do you have any information on what the processes are that are taking the
time?  'top' will tell you this.

--
Tom Barringer
Senior Technical Consultant
Progress Software


> -----Original Message-----
> From: owner-linuxperf@nl.linux.org
> [mailto:owner-linuxperf@nl.linux.org]On Behalf Of Jochen Frey
> Sent: Monday, August 20, 2001 9:52 PM
> To: linuxperf@nl.linux.org
> Subject: [linuxperf] system time on SMP
>
>
> Hi there, I am new to this list, so please bear with me. I searched the
> list, but I might have missed stuff.
>
> The symptom: I am running performance test on a multi processor
> machine, and
> when I put it under load, the processors spend 50% of their time in user
> processes and 50% of the time in system processes (sometimes it's 60:40).
> This is not what I'd expect, I'd expect close to 85% of the time in user
> processes (realistic?).
>
> The question: Any pointers as to what the system might be doing?
> I used sar,
> and it's not swapping, there's plenty of memory (2GB) (but maybe
> not used),
> and network is not an issue.
>
> The architecture:
> * SW: LAMP (red hat 7.1, apache, mySQL, PHP) most of those in the latest
> versions.
> * HW: Dell 8450 (8 processors, 2GB Memory)
>
> The load type: Lots of brief stateless requests (short translations),
> requiring many simple 'selects' from mySQL (one table only, relatively
> simple lookups using indexes).
>
> Any pointers / suggestions / etc?
>
> Thanks so much!
> Jo
>
> -
> Linuxperf:    Working list for the Linux Performance tuning site
> Archive:      http://mail.nl.linux.org/linuxperf/
> Web site:     http://linuxperf.nl.linux.org/
>

-
Linuxperf:    Working list for the Linux Performance tuning site
Archive:      http://mail.nl.linux.org/linuxperf/
Web site:     http://linuxperf.nl.linux.org/

-
Linuxperf:    Working list for the Linux Performance tuning site
Archive:      http://mail.nl.linux.org/linuxperf/
Web site:     http://linuxperf.nl.linux.org/