Re: [squid-users] Squid on SMP

tor 2006-06-08 klockan 13:40 +0600 skrev Sergey Velikanov:
> I'm try install squid to SMP machine, I've ran two copy of squid, and
> balance load between them. But I haven't seen any difference if I run
> one or two copy of squid, first processor has higher load then second.
> Is it normal? How can I see what cpu number squid used?

Normally the OS scheduler distributes applications on the available CPUs
in the way it thinks is most reasonable. Which means applications is not
strictly limited to one CPU but bounces around a bit between the CPUs.

However, networks cards and other hardware gets quite tightly coupled to
one of the CPUs, and applications dependent on results of that tend to
get scheduled onto the same CPU simply because they are waiting on the
results..

Usually there is system tools to manually re-balance the decisions if
you don't agree with the scheduler for some reason. On linux this
includes irqbalance, taskset, and a few other tools. Other OS:es uses
other tools..

Likewise there is no uniform standard to inspect which processes gets
scheduled on which CPU.

On Linux you can get quite detalied statistics on the CPU usage and a
lot of other things from oprofile if you insist on it, but it's not a
very easy tool to work with (it's a low level general system profiler,
not just for displaying CPU usage..)

Regards
Henrik