Subject: Re: SMP (was Re: VXLOCK race? )
To: None <tholo@SigmaSoft.COM>
From: David S. Miller <>
List: tech-kern
Date: 05/11/1996 17:56:56
   Date: Sat, 11 May 1996 11:43:51 -0700
   From: Thorsten Lockert <tholo@SigmaSoft.COM>

   Note that 4.4BSD-Lite2 has some MP support, particularily in the
   file system code.  The lock manager that has been put into Lite2
   (mostly a rewrite of the Mach lock manager) is not the fastest
   lock manager I have seen tho, and it does not change SLP levels
   as you aquire locks.

May I suggest going for a master-slave and/or giantlock implementation
at first go?  The biggest set of headaches when going SMP will be
getting the hardware to talk correctly and adjusting your head into
the fact that multiple cpu's are there. ;-) Believe me, I learned all
too well 3 months ago how linearly I had been thinking all my life.

Once you can get ms/glock working to your satisfaction, then you
should be narrowing down things into major kernel subsections -->
working out the obvious dependancies --> enforcing a lock acuisition
ordering rule --> throwing the locks in to see how it looks.  Even
when you reach the medium grain locking here you will already be
nearly forced to rework major sections of the kernel.

If you want a brain to pick, feel free to ask me questions.

David S. Miller