amd64/127451: top(1): incorrect load shown on quad core

[Tomas Randa]

I have similar problem on my Xeon5000 quad core system with 7.1 PRERELEASE / AMD64. Tried anybody to change scheduler from ULE to 4BSD?
I tried to change some sysctl variables, but no success.

Thanks for help.

Tomas Randa


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

From: miks at skynet.lv
To: bug-followup at FreeBSD.org, miks at skynet.lv
Cc:  
Subject: Re: amd64/127451: top(1): incorrect load shown on quad core
Date: Thu, 18 Sep 2008 21:50:06 +0300



I got load average around 0.5, and top show something like this
"1021 processes: 1 running, 1020 sleeping
CPU states:  4.9% user,  0.0% nice,  3.6% system,  0.9% interrupt,
90.6% idle" - this all is ok.

then once in 2-5 minutes, there for 2-3 seconds are:
"1020 processes:67 running, 912 sleeping, 1 zombie, 40 lock
CPU states:  3.0% user,  0.0% nice, 96.7% system,  0.3% interrupt,
0.0% idle" - this is the problem.

after this load average is 20-30 and dropping in 2-3min to 0.5. during
this time system is very slow. even ssh session is freezing.
most of processes are fastcgi/php, so there is not one big resource
hungry process.

found similar problem here: http://unix.derkeiler.com/Mailing-Lists/FreeBSD/stable/2007-11/msg00551.html