Date: Sun, 10 Oct 2010 16:55:58 +1100 (EST) From: Ian Smith <smithi@nimnet.asn.au> To: kes-kes@yandex.ru Cc: freebsd-questions@freebsd.org Subject: Re: How to obtain which interrupts cause system to hang? Message-ID: <20101010161330.R2036@sola.nimnet.asn.au> In-Reply-To: <20101009204915.0360410656F1@hub.freebsd.org> References: <20101009204915.0360410656F1@hub.freebsd.org>
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In freebsd-questions Digest, Vol 331, Issue 13, Message: 8
On Sat, 9 Oct 2010 20:05:48 +0300 ??????? ??????? <kes-kes@yandex.ru> wrote:
> Content-Type: text/plain; charset=windows-1251
^^^^^^^^^^^^
Hi KES, long time ..
> #systat -v
> 1 users Load 0.74 0.71 0.55 Oct 9 19:53
[..]
> Proc: Interrupts
> r p d s w Csw Trp Sys Int Sof Flt 24 cow 2008 total
> 2 3 39 23k 67 563 9 1710 47 15 zfod 9 ata0 irq14
> ozfod nfe0 irq23
> 23.1%Sys 50.8%Intr 1.3%User 0.0%Nice 24.8%Idle %ozfod 1999 cpu0: time
> | | | | | | | | | | | daefr
> ============+++++++++++++++++++++++++> 6 prcfr
Yes, system and esp. interrupt time is heavy .. 23k context switches!?
In addition to b. f.'s good advice .. as you later said, 2000 Hz slicing
_should_ be ok, unless a slow CPU? Or perhaps a fast CPU throttled back
too far .. powerd? Check sysctl dev.cpu.0.freq while this is happening.
Disable p4tcc if it's a modern CPU; that usually hurts more than helps.
Disable polling if you're using that .. you haven't provided much info,
like is this with any network load, despite nfe0 showing no interrupts?
> #top
> last pid: 24571; load averages: 0.10, 0.49, 0.50 up 0+19:15:01 19:56:36
> 42 processes: 3 running, 39 sleeping
> CPU: 0.7% user, 0.0% nice, 21.0% system, 36.3% interrupt, 41.9% idle
> Mem: 305M Active, 767M Inact, 252M Wired, 468K Cache, 213M Buf, 650M Free
> Swap: 4063M Total, 4063M Free
>
> PID USERNAME THR PRI NICE SIZE RES STATE TIME WCPU COMMAND
> 1054 bind 4 4 0 134M 109M kqread 0:51 0.00% named
> 986 root 1 44 0 5692K 1408K RUN 0:50 0.00% syslogd
> 1162 clamav 1 4 0 4616K 1468K accept 0:46 0.00% smtp-gated
> 11731 clamav 1 20 0 27948K 9728K pause 0:03 0.00% freshclam
> 11791 root 1 -58 0 7848K 4120K bpf 0:02 0.00% arpwatch
> 13208 root 1 44 0 10700K 4144K select 0:01 0.00% sendmail
> 13298 root 1 8 0 6748K 1440K nanslp 0:00 0.00% cron
> 12802 root 1 44 0 22880K 4004K select 0:00 0.00% sshd
>
>
> How to obtain what nasty happen, which process take 36-50% of CPU
> resource?
Try 'top -S'. It's almost certainly system process[es], not shown above.
cheers, Ian
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