[Dnsmasq-discuss] excessive cpu consumption in 2.39rc1

[Carlos Carvalho]

Simon Kelley (simon at thekelleys.org.uk) wrote on 12 April 2007 22:37:
 >> I found strange that it complained about overflow even without
 >> log-queries and log-dhcp but this only happened right after starting,
 >> so it could be because of the overall load.
 >There are quite a lot of log lines created at startup, so that makes 
 >some sense.

Agreed.

 >> I'll turn the logging again and use --log-max=0 to see what happens.
 >
 >OK. I suspect that this a symptom of a loaded system: the trade-off for 
 >lost logging is that dnsmasq keeps working fast, without waiting for syslog.
 >
 >If you see messages like this, when dnsmasq shouldn't be logging, that's 
 >  a bug.

It happens only at startup so it's ok.

 >Increasing log-max (the default is 5) will reduce the number of lost 
 >messages.

I really have a problem with this new code. The server is loaded and
dnsmasq takes a long time to answer. I've got some angry users
today...

I tried log-max=1000 to no avail. I had to disable logging to restore
the service (make it fast enough).

It seems that log-max is limited to 25. This shouldn't happen...

Another alternative would be to disable the new code. In my case
there's no risk of deadlock because the server that runs syslog (and
dnsmasq) doesn't use dnsmasq itself, it's only for the clients.
However setting log-max high enough should have the same effect.