Re: 2048 CPUs [was: Re: New filesystem for Linux]

[David Chinner]

On Sat, Nov 04, 2006 at 11:36:49PM +0100, Mikulas Patocka wrote:
> >>Does one Linux kernel run on system with 1024 cpus? I guess it
> >>must fry spinlocks... (or even lockup due to spinlock livelocks)
> >
> >The SGI Altix can have 2048 CPUs.
> 
> And does it run one image of Linux? Or more images each on few cpus?

One image.

> How do they solve problem with spinlock livelocks?

By replacing contended spinlocks withsleeping locks, using no-lock
techniques (e.g. per-cpu) or changing the algorithm to remove the
contention point.

w.r.t filesystem locking scalability, you should read this paper:

http://oss.sgi.com/projects/xfs/papers/ols2006/ols-2006-paper.pdf

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group
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