99% CPU usage in System (Was: Re: vinum in 4.x poor performer?)

Chad Leigh -- Shire.Net LLC chad at shire.net
Wed Feb 9 21:00:32 PST 2005


On Feb 9, 2005, at 6:34 PM, Marc G. Fournier wrote:

>
> Most odd, there definitely has to be a problem with the Dual-Xeon 
> ysystem ... doing the same vmstat on my other vinum based system, 
> running more, but on a Dual-PIII shows major idle time:
>
> # vmstat 5
>  procs      memory      page                    disks     faults      
> cpu
>  r b w     avm    fre  flt  re  pi  po  fr  sr da0 da1   in   sy  cs 
> us sy id
> 20 1 0 4088636 219556 1664   1   2   1 3058 217   0   0  856 7937 2186 
> 51 15 34
> 20 1 0 4115372 224220  472   0   0   0 2066   0   0  35  496 2915 745  
> 7  7 86
> 10 1 0 4125252 221788  916   0   0   0 2513   0   2  71  798 4821 1538 
>  6 11 83
>  9 1 0   36508 228452  534   0   0   2 2187   0   0  46  554 3384 1027 
>  3  8 89
> 11 1 0   27672 218828  623   0   6   0 2337   0   0  61  583 2607 679  
> 3  9 88
> 16 1 0    5776 220540  989   0   0   0 2393   0   9  32  514 3247 1115 
>  3  8 90
>
> Which leads me further to believe this is a Dual-Xeon problem, and 
> much further away from believing it has anything to do with software 
> RAID :(

I only use AMD, so I cannot provide specifics, but look in the BIOS at 
boot time and see if there is anything strange looking in the settings.

Chad

>
>
> On Wed, 9 Feb 2005, Marc G. Fournier wrote:
>
>>
>> still getting this:
>>
>> # vmstat 5
>> procs      memory      page                    disks     faults      
>> cpu
>> r b w     avm    fre  flt  re  pi  po  fr  sr da0 da1   in   sy  cs 
>> us sy id
>> 11 2 0 3020036 267944  505   2   1   1 680  62   0   0  515 4005 918  
>> 7 38 55
>> 19 2 0 3004568 268672  242   0   0   0 277   0   0   3  338 2767 690  
>> 1 99  0
>> 21 2 0 2999152 271240  135   0   0   0 306   0   6   9  363 1749 525  
>> 1 99  0
>> 13 2 0 3001508 269692   87   0   0   0  24   0   3   3  302 1524 285  
>> 1 99  0
>> 17 2 0 3025892 268612   98   0   1   0  66   0   5   6  312 1523 479  
>> 3 97  0
>>
>> Is there a way of determining what is sucking up so much Sys time?  
>> stuff like pperl scripts running and such would use 'user time', no?  
>> I've got some high CPU processes running, but would expect them to be 
>> shooting up the 'user time' ...
>>
>> USER         PID %CPU %MEM   VSZ  RSS  TT  STAT STARTED      TIME 
>> COMMAND
>> setiathome 21338 16.3  0.2  7888 7408  ??  RJ    9:05PM   0:11.35 
>> /usr/bin/perl -wT /usr/local/majordomo/bin/mj_queuerun -v 0
>> setiathome 21380 15.1  0.1  2988 2484  ??  RsJ   9:06PM   0:02.42 
>> /usr/bin/perl -wT /usr/local/majordomo/bin/mj_enqueue -r -d 
>> postgresql.org -l pgsql-sql -P10 -p10
>> setiathome 21384 15.5  0.1  2988 2484  ??  RsJ   9:06PM   0:02.31 
>> /usr/bin/perl -wT /usr/local/majordomo/bin/mj_enqueue -r -d 
>> postgresql.org -l pgsql-docs -P10 -p10
>> setiathome 21389 15.0  0.1  2720 2216  ??  RsJ   9:06PM   0:02.06 
>> /usr/bin/perl -wT /usr/local/majordomo/bin/mj_enqueue -r -d 
>> postgresql.org -l pgsql-hackers -P10 -p10
>> setiathome 21386 13.7  0.1  2720 2216  ??  RsJ   9:06PM   0:02.03 
>> /usr/bin/perl -wT /usr/local/majordomo/bin/mj_enqueue -r -d 
>> postgresql.org -l pgsql-ports -P10 -p10
>> setiathome 21387 13.2  0.1  2724 2220  ??  RsJ   9:06PM   0:01.92 
>> /usr/bin/perl -wT /usr/local/majordomo/bin/mj_enqueue -r -d 
>> postgresql.org -l pgsql-interfaces -P10 -p10
>> setiathome 21390 14.6  0.1  2724 2216  ??  RsJ   9:06PM   0:01.93 
>> /usr/bin/perl -wT /usr/local/majordomo/bin/mj_enqueue -o -d 
>> postgresql.org -l pgsql-performance -P10 -p10
>> setiathome 21330 12.0  0.2  8492 7852  ??  RJ    9:05PM   0:15.55 
>> /usr/bin/perl -wT /dev/fd/3//usr/local/www/mj/mj_wwwusr (perl5.8.5)
>> setiathome  7864  8.9  0.2  8912 8452  ??  RJ    7:20PM  29:54.88 
>> /usr/bin/perl -wT /usr/local/majordomo/bin/mj_trigger -t hourly
>>
>> Is there some way of finding out where all the Sys Time is being 
>> used? Something more fine grained them what vmstat/top shows?
>>
>>
>> On Wed, 9 Feb 2005, Loren M. Lang wrote:
>>
>>> On Wed, Feb 09, 2005 at 02:32:30AM -0400, Marc G. Fournier wrote:
>>>> Is there a command that I can run that provide me the syscall/sec 
>>>> value,
>>>> that I could use in a script?  I know vmstat reports it, but is 
>>>> there an
>>>> easier way the having to parse the output? a perl module maybe, that
>>>> already does it?
>>> vmstat shouldn't be too hard to parse, try the following:
>>> vmstat|tail -1|awk '{print $15;}'
>>> To print out the 15th field of vmstat.  Now if you want vmstat to 
>>> keep
>>> running every five seconds or something, it's a little more 
>>> complicated:
>>> vmstat 5|grep -v 'procs\|avm'|awk '{print $15;}'
>>>> Thanks ...
>>>> On Wed, 9 Feb 2005, Marc G. Fournier wrote:
>>>>> On Tue, 8 Feb 2005, Dan Nelson wrote:
>>>>>> Details on the array's performance, I think.  Software RAID5 will
>>>>>> definitely have poor write performance (logging disks solve that
>>>>>> problem but vinum doesn't do that), but should have excellent read
>>>>>> rates.  From this output, however:
>>>>>>> systat -v output help:
>>>>>>>    4 users    Load  4.64  5.58  5.77
>>>>>>> Proc:r  p  d  s  w    Csw  Trp  Sys  Int  Sof  Flt
>>>>>>>    24     9282       949 8414*****  678  349 8198
>>>>>>> 54.6%Sys   0.2%Intr 45.2%User  0.0%Nice  0.0%Idl
>>>>>>> Disks   da0   da1   da2   da3   da4 pass0 pass1
>>>>>>> KB/t   5.32  9.50 12.52 16.00  9.00  0.00  0.00
>>>>>>> tps      23     2     4     3     1     0     0
>>>>>>> MB/s   0.12  0.01  0.05  0.04  0.01  0.00  0.00
>>>>>>> % busy    3     1     1     1     0     0     0
>>>>>> , it looks like your disks aren't being touched at all.  You are 
>>>>>> doing
>>>>>> over 99999 syscalls/second, though, which is mighty high.  The 
>>>>>> 50% Sys
>>>>>> doesn't look good either.  You may have a runaway process doing 
>>>>>> some
>>>>>> syscall over and over.  If this is not an MPSAFE syscall (see
>>>>>> /sys/kern/syscalls.master ), it will also prevent other processes 
>>>>>> from
>>>>>> making non-MPSAFE syscalls, and in 4.x that's most of them.
>>>>> Wow, that actually pointed me in the right direction, I think ... 
>>>>> I just
>>>>> killed an http process that was using alot of CPU, and syscalls 
>>>>> drop'd
>>>>> down to a numeric value again ... I'm still curious as to why this 
>>>>> only
>>>>> seem sto affect my Dual-Xeon box though :(
>>>>> Thanks ...
>>>>> ----
>>>>> Marc G. Fournier           Hub.Org Networking Services 
>>>>> (http://www.hub.org)
>>>>> Email: scrappy at hub.org           Yahoo!: yscrappy              
>>>>> ICQ: 7615664
>>>>> _______________________________________________
>>>>> freebsd-questions at freebsd.org mailing list
>>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
>>>>> To unsubscribe, send any mail to
>>>>> "freebsd-questions-unsubscribe at freebsd.org"
>>>> ----
>>>> Marc G. Fournier           Hub.Org Networking Services 
>>>> (http://www.hub.org)
>>>> Email: scrappy at hub.org           Yahoo!: yscrappy              ICQ: 
>>>> 7615664
>>>> _______________________________________________
>>>> freebsd-questions at freebsd.org mailing list
>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
>>>> To unsubscribe, send any mail to 
>>>> "freebsd-questions-unsubscribe at freebsd.org"
>>> -- 
>>> I sense much NT in you.
>>> NT leads to Bluescreen.
>>> Bluescreen leads to downtime.
>>> Downtime leads to suffering.
>>> NT is the path to the darkside.
>>> Powerful Unix is.
>>> Public Key: ftp://ftp.tallye.com/pub/lorenl_pubkey.asc
>>> Fingerprint: B3B9 D669 69C9 09EC 1BCD  835A FAF3 7A46 E4A3 280C
>>
>> ----
>> Marc G. Fournier           Hub.Org Networking Services 
>> (http://www.hub.org)
>> Email: scrappy at hub.org           Yahoo!: yscrappy              ICQ: 
>> 7615664
>> _______________________________________________
>> freebsd-questions at freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
>> To unsubscribe, send any mail to 
>> "freebsd-questions-unsubscribe at freebsd.org"
>>
>
> ----
> Marc G. Fournier           Hub.Org Networking Services 
> (http://www.hub.org)
> Email: scrappy at hub.org           Yahoo!: yscrappy              ICQ: 
> 7615664
> _______________________________________________
> freebsd-questions at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> To unsubscribe, send any mail to 
> "freebsd-questions-unsubscribe at freebsd.org"



More information about the freebsd-questions mailing list