Date: Mon, 28 Feb 2005 15:31:28 -0800 From: Jeff Behl <jbehl@fastclick.com> To: Dan Nelson <dnelson@allantgroup.com> Cc: freebsd-stable@freebsd.org Subject: Re: vmstat/iostat/top all fail to report CPU usage Message-ID: <4223A9D0.8020105@fastclick.com> In-Reply-To: <20050228185042.GH8778@dan.emsphone.com> References: <422366DE.6020001@fastclick.com> <20050228185042.GH8778@dan.emsphone.com>
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Dan Nelson wrote:
>In the last episode (Feb 28), Jeff Behl said:
>
>
>>as reported in bug: bin/60385
>>
>>this is still occurring in almost all of our systems, even those at
>>stable, and is pretty major issue. any known progress on this? we're
>>running ibm e325 servers.
>>
>>FreeBSD www3 5.3-STABLE FreeBSD 5.3-STABLE #1: Tue Feb 15 10:09:17 PST
>>2005 root@www3.cdn.sjc:/usr/obj/usr/src/sys/SMP amd64
>>
>>
>
>Here's the workaround I use on a machine here that loses its stat clock
>after a week or so of uptime. Put this in /etc/crontab:
>
># Flaky clock. Check it every 5 minutes.
>*/5 * * * * root /usr/local/bin/fixrtc
>
>.. and this in /usr/local/bin/fixrtc:
>
>#! /bin/sh
>
># get the interrupt rate for the stat clock over one second
>getticks() {
> ( vmstat -i ; sleep 1 ; vmstat -i ) |
> awk '/rtc/ { if (sum) sum+=$3; else sum-=$3 } END { print sum }'
>}
>
>ticks=$(getticks)
>
># It should be firing at 128 hz. If not, kick it
>if [ $ticks -lt 64 ] ; then
> echo "Stat clock has died. Attempting to reset."
> echo
> /etc/rc.d/ntpd stop
> echo
> /usr/sbin/ntpdate -b ntp.pool.org
> echo
> /etc/rc.d/ntpd start
> echo
> echo "RTC interrupt rate is now $(getticks)"
>fi
>
>
>
>
excellent, thanks much Dan. this does the trick nicely and will help a
lot. hopefully there'll be a commit for the real fix for 5.4.
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