A bug in syslogd?

[Cameron Simpson]

On 23Jan2009 17:34, Peter Teoh <htmldeveloper at gmail.com> wrote:
| I did a simple thing - modified my syslog.conf:
| 
| cat /etc/syslog.conf
| mail.none;authpriv.none;cron.none               /var/log/messages
| 
| So virtually, there is nothing to go to /var/log/messages, although my
| dmesg's output did output a lot of other stuff....as I instrumented
| the kernel to do printk()....something like every file traversal will
| generate several entries in dmesg output.
| 
| Nevertheless, since /var/log/messages to get, as I check, its content
| is always zero (after I did an initial truncation) - why is syslogd
| showing such a high performance:
[...]
| Over a period of time, I observed that klogd and syslogd is toggling
| to be among the top few candidate all the time - toggling, meaning
| switching between one and another.
| 
| Can someone explained this behavior?   Shouldn't the syslogd be
| consuming almost zero cpu % since there is zero output to
| /var/log/messages?

Not really. Your kernel logging is still _all_ going through syslogd,
which is quietly deciding not to _copy_ it into the messages file. But
it still has to consider and then discard) every kernel message.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au> DoD#743
http://www.cskk.ezoshosting.com/cs/

Anagram: Information superhighway <==> I'm on a huge wispy rhino fart.