A bug in syslogd?

[Peter Teoh]

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:

First snapshot:

27790 root      20   0  268m 203m  14m S  4.3 20.2   2:38.36 opera
 3459 root      20   0  315m  33m 8160 S  2.6  3.3   8:16.22 Xorg
  532 root      15  -5     0    0    0 S  0.3  0.0   0:01.13 ata/0
 2417 root      20   0  1888  648  548 S  0.3  0.1   0:01.73 syslogd
 3770 root      20   0 73928  10m 4688 S  0.3  1.0   0:15.76
gnome-terminal
 3772 root      20   0  5092  532  484 S  0.3  0.1   0:00.16
wpa_supplicant
28349 root      20   0  2344 1028  788 R  0.3  0.1   0:00.05 top
    1 root      20   0  2224  604  564 S  0.0  0.1   0:01.11 init

Next snapshot:

 3459 root      20   0  315m  33m 8160 S 11.2  3.3   8:18.51 Xorg
 2420 root      20   0  1828  460  392 R  1.9  0.0   0:01.82 klogd
27790 root      20   0  268m 203m  14m S  1.9 20.2   2:39.87 opera
28350 root      20   0  2340  936  700 R  1.9  0.1   0:00.01 top
    1 root      20   0  2224  604  564 S  0.0  0.1   0:01.11 init
    2 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 kthreadd
    3 root      RT  -5     0    0    0 S  0.0  0.0   0:00.00
migration/0
    4 root      15  -5     0    0    0 S  0.0  0.0   0:00.40
ksoftirqd/0
    5 root      RT  -5     0    0    0 S  0.0  0.0   0:00.00
watchdog/0

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?

PS:   I did restart syslogd after /etc/syslogd.conf modification.

-- 
Regards,
Peter Teoh