From: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
To: "'Zach Brown'" <zach.brown@oracle.com>
Cc: "'Andrew Morton'" <akpm@osdl.org>, <linux-aio@kvack.org>,
       <linux-kernel@vger.kernel.org>, "'Benjamin LaHaise'" <bcrl@kvack.org>,
       <suparna@in.ibm.com>
Subject: RE: [patch] aio: streamline read events after woken up
Date: Tue, 2 Jan 2007 18:00:40 -0800
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Zach Brown wrote on Tuesday, January 02, 2007 5:06 PM
> To: Chen, Kenneth W
> > Given the previous patch "aio: add per task aio wait event condition"
> > that we properly wake up event waiting process knowing that we have
> > enough events to reap, it's just plain waste of time to insert itself
> > into a wait queue, and then immediately remove itself from the wait
> > queue for *every* event reap iteration.
> 
> Hmm, I dunno.  It seems like we're still left with a pretty silly loop.
> 
> Would it be reasonable to have a loop that copied multiple events at  
> a time?  We could use some __copy_to_user_inatomic(), it didn't exist  
> when this stuff was first written.

It sounds reasonable, but I think it will be complicated because of
kmap_atomic on the ring buffer, along with tail wraps around ring
buffer index there.  By then, most of you would probably veto the
patch anyway ;-)

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