syslogd and bzip2 hogs after 6.3 to 7.0 upgrade

[Kris Kennaway]

Neil Darlow wrote:
> Hi,
> 
> I have recently upgraded from RELENG_6_3 to RELENG_7_0 via the source 
> method. I followed the upgrade instructions in the 7.0 release notes and 
> rebuilt all ports successfully.
> 
> My hardware is a VIA EPIA PD10000 (VIA Centerhauls CPU) with gmirrored 
> IDE disks and GELI encrypted swap (using padlock).
> 
> My kernel is GENERIC with removal of 386, 486 and 585 CPU support and 
> addition of options for:
> 
> DEVICE_POLLING, HZ=1000, ALTQ, PFLOG, PFSYNC and QUOTA.
> 
> I use PF for my firewalling and device polling on my two integrated Via 
> Rhine NICs.
> 
> This setup worked great under RELENG_6_2 and RELENG_6_3 (only for a 
> short period due to RELENG_7_0 becoming available) with absolutely no 
> issues whatever.
> 
> Since upgrading to RELENG_7_0 I have a problem when the nightly rotation 
> of logfiles occurs. A number of bzip2 processes appear which, with 
> syslogd, consume huge amounts of CPU.

FreeBSD 7 switches to bzipping logfiles rather than gzipping.

> Looking at the output of "top" I see that my interrupt CPU usage has 
> increased to 46% and userland CPU usage to 44%. The remainder is system 
> and there is no idle CPU time left.

This should be unrelated to bzip since that is purely CPU bound.  What 
is causing the interrupts?  Check vmstat -i.  That is likely to be your 
real problem.

Kris