Re: [patch 2/2] x86,pat Convert memtype_lock into an rw_lock.

From: Peter Zijlstra
Date: Wed Mar 24 2010 - 07:32:58 EST


On Wed, 2010-03-17 at 16:19 -0800, Suresh Siddha wrote:
> On Wed, 2010-03-17 at 12:51 -0700, H. Peter Anvin wrote:
> > Well, as you know :) tglx and I are on the road ... I'll try to get to it on Friday before I take off again.
>
> Also I talked to Thomas about this rwlock conversion and he referred to
> RT issues with rwlock. And the best is to avoid this using RCU.

Its not just RT, even for mainline rwlock_t is a massive pain and often
is no better (actually worse) than a spinlock due to the massive
cacheline bouncing it introduces.


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