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Date: Wed, 14 May 2008 09:56:18 -0700 (PDT)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Robin Holt <holt@sgi.com>
cc: Nick Piggin <npiggin@suse.de>, Nick Piggin <nickpiggin@yahoo.com.au>,
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Subject: Re: [PATCH 08 of 11] anon-vma-rwsem
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On Wed, 14 May 2008, Robin Holt wrote:
> 
> Would it be acceptable to always put a sleepable stall in even if the 
> code path did not require the pages be unwritable prior to continuing?  
> If we did that, I would be freed from having a pool of invalidate 
> threads ready for XPMEM to use for that work. Maybe there is a better 
> way, but the sleeping requirement we would have on the threads make most 
> options seem unworkable.

I'm not understanding the question. If you can do you management outside 
of the spinlocks, then you can obviously do whatever you want, including 
sleping. It's changing the existing spinlocks to be sleepable that is not 
acceptable, because it's such a performance problem.

		Linus