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List:       freebsd-smp
Subject:    Re: libc_r locking... why?
From:       Bernd Walter <ticso () mail ! cicely ! de>
Date:       2001-07-14 10:55:34
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On Tue, Jul 03, 2001 at 03:06:08AM -0700, Terry Lambert wrote:
> Sequent had a BSD-based OS called Dynix, which had a lot
> of smart things in it, including per processor resource
> pools, which is what enabled it to scale so large: it
> removed everything it could from the inter-CPU contention
> domain.  FreeBSD is trying to take much of that approach.
> Unfortunately, they went to System V (SVR3), which then
> introduced a big giant lock on SMP-unsafe subsystems; in
> particular, only one processor was allowed into the VFS
> at a time, which sucked -- if you started two "ls -R"
> processes on two processors, then one would complete,
> and then the other -- but the second one wouldn't start
> until the lock was let go, so they were effectively being
> serialized, while one CPU was idle.  It really ruined the
> usefulness of the machine.

I own a Mai BasicFour GPx5070 machine with 2 CPUs.
The OS is named BOSS which seems to be a Sequent SysV.
I can agree with the ls -R situation.

-- 
B.Walter              COSMO-Project         http://www.cosmo-project.de
ticso@cicely.de         Usergroup           info@cosmo-project.de


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