Performance issue

Scott Long scottl at samsco.org
Mon May 9 10:23:08 PDT 2005


Ewan Todd wrote:
>>5.3 ships with SMP turned on, which makes lock operations rather 
>>expensive on single-processor machines.  4.x does not have SMP
>>turned on by default.  Would you be able to re-run your test with
>>SMP turned off?
>>
> 
> 
> I'm pretty sure there's no SMP in this kernel.
> 
>   #cd /usr/src/sys/i386/conf
>   #fgrep SMP MYKERNEL
>   #
> 
> GENERIC has no SMP in it, but there's a second "GENERIC" kernel conf
> called "SMP", which simply says:
> 
>   include GENERIC
>   options SMP
> 
> However, sysctl seems to show smp not active, but not disabled.   Is
> that anything to worry about?
> 
>   #sysctl -a | grep smp
>   kern.smp.maxcpus: 1
>   kern.smp.active: 0
>   kern.smp.disabled: 0
>   kern.smp.cpus: 1
>   debug.psmpkterrthresh: 2
> 
> 
> -e
> 

Bah, you're right, sorry for the confusion.  Too many releases in my
mind, they all seem like a blur.

Scott


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