Re: [patch] fix spinlock-debug looping

From: Ingo Molnar
Date: Tue Jun 20 2006 - 05:38:14 EST



* Andrew Morton <akpm@xxxxxxxx> wrote:

> > Spinlocks are alot fairer. Or as a simple experiment,
> > s/read_lock/write_lock, as the patch below (against rc6-mm2) does.
> > This is phase #1, if it works out we can switch tree_lock to a
> > spinlock. [write_lock()s are roughly as fair to each other as
> > spinlocks - it's a bit more expensive but not significantly] Builds
> > & boots fine here.
>
> tree_lock was initially an rwlock. Then we made it a spinlock. Then
> we made it an rwlock. We change the dang thing so often we should
> make it a macro ;)

ha! In -rt we can change types of locks by changing the type definition
and the declaration only ;-) [It makes for some confusing reading though
if done without restraint]

> Let's just make it a spinlock and be done with it. Hopefully Dave or
> ccb@xxxxxxx (?) will be able to test it. I was planning on doing a
> patch tomorrowish.

ok. Until that happens the patch i sent can be used for testing.

Ingo
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