Re: [PATCH, RFC] hacks to allow -rt to run kernbench on POWER

From: Paul E. McKenney
Date: Thu Nov 01 2007 - 11:50:53 EST


On Thu, Nov 01, 2007 at 08:15:28AM +1100, Benjamin Herrenschmidt wrote:
>
> > So as Paul mentioned, spin_lock is now a mutex. There is a new
> > raw_spinlock however (simply change the way it is declared, calling
> > conventions are the same) which is used in a very few areas where a
> > traditional spin_lock is truly necessary. This may or may not be one of
> > those times, but I wanted to point it out.
>
> Yeah, I figured that. My main worry has more to do with some fishy
> assumptions the powerpc VM code does regarding what can and cannot
> happen in those locked sections, among other things. I'll have to sit
> and think about it for a little while to convince myself we are ok ...
> or not. Plus we do keep track of various MM related things in per-CPU
> data structures but it looks like Paul already spotted that.

My concern would be that I failed to spot all of them. ;-)

Thanx, Paul
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