Re: Linux 2.6.25-rc2

[Ingo Molnar]

* Pekka Enberg <penberg@xxxxxxxxxxxxxx> wrote:

> Mathieu, Christoph is on vacation and I'm not at all that familiar 
> with this cmpxchg_local() optimization, so if you could take a peek at 
> this bug report to see if you can spot something obviously wrong with 
> it, I would much appreciate that.

hm, it's bad for at least one other reason as well (which is probably 
unrelated to this crash):

 /*
  * Currently fastpath is not supported if preemption is enabled.
  */
 #if defined(CONFIG_FAST_CMPXCHG_LOCAL) && !defined(CONFIG_PREEMPT)
 #define SLUB_FASTPATH
 #endif

such !PREEMPT exceptions tend to show "i didnt want to think too hard 
about the preemptible case so just turn it off" thinking.

Also, why isnt this "SLUB_FASTPATH" flag done in the Kconfig space?

	Ingo
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