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Date:      Mon, 9 May 2005 13:21:11 -0400
From:      Ewan Todd <ewan@mathcode.net>
To:        Scott Long <scottl@samsco.org>
Cc:        freebsd-stable <freebsd-stable@freebsd.org>
Subject:   Re: Performance issue
Message-ID:  <20050509172111.GH281@mathcode.net>
In-Reply-To: <427F9890.7010104@samsco.org>
References:  <20050509150018.GF281@mathcode.net> <427F8076.7030105@samsco.org> <20050509170316.GG281@mathcode.net> <427F9890.7010104@samsco.org>

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> 
> 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



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