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Date: Tue, 6 Feb 2001 20:32:19 +0100
From: Jens Axboe <axboe@suse.de>
To: Ben LaHaise <bcrl@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>, "Stephen C. Tweedie" <sct@redhat.com>,
        Linus Torvalds <torvalds@transmeta.com>,
        Alan Cox <alan@lxorguk.ukuu.org.uk>,
        Manfred Spraul <manfred@colorfullife.com>, Steve Lord <lord@sgi.com>,
        Linux Kernel List <linux-kernel@vger.kernel.org>,
        kiobuf-io-devel@lists.sourceforge.net, Ingo Molnar <mingo@redhat.com>
Subject: Re: [Kiobuf-io-devel] RFC: Kernel mechanism: Compound event wait
Message-ID: <20010206203219.A2975@suse.de>
In-Reply-To: <Pine.LNX.4.30.0102061955380.7919-100000@elte.hu> <Pine.LNX.4.30.0102061402200.15204-100000@today.toronto.redhat.com>
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In-Reply-To: <Pine.LNX.4.30.0102061402200.15204-100000@today.toronto.redhat.com>; from bcrl@redhat.com on Tue, Feb 06, 2001 at 02:11:23PM -0500
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On Tue, Feb 06 2001, Ben LaHaise wrote:
> > > 	- make asynchronous io possible in the block layer.  This is
> > > 	  impossible with the current ll_rw_block scheme and io request
> > > 	  plugging.
> >
> > why is it impossible?
> 
> s/impossible/unpleasant/.  ll_rw_blk blocks; it should be possible to have
> a non blocking variant that does all of the setup in the caller's context.
> Yes, I know that we can do it with a kernel thread, but that isn't as
> clean and it significantly penalises small ios (hint: databases issue
> *lots* of small random ios and a good chunk of large ios).

So make a non-blocking variant, not a big deal. Users of async I/O
know how to deal with resource limits anyway.

-- 
Jens Axboe

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