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Date: Thu, 6 Aug 2015 17:00:04 -0700
From: Kent Overstreet <kent.overstreet@gmail.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Ming Lin <mlin@kernel.org>, Mike Snitzer <snitzer@redhat.com>,
        lkml <linux-kernel@vger.kernel.org>, Jens Axboe <axboe@kernel.dk>,
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        Philip Kelleher <pjk1939@linux.vnet.ibm.com>,
        Minchan Kim <minchan@kernel.org>, Nitin Gupta <ngupta@vflare.org>,
        Oleg Drokin <oleg.drokin@intel.com>,
        Andreas Dilger <andreas.dilger@intel.com>,
        Ming Lin <ming.l@ssi.samsung.com>
Subject: Re: [PATCH v5 01/11] block: make generic_make_request handle
 arbitrarily sized bios
Message-ID: <20150807000004.GB30757@moria.home.lan>
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On Tue, Aug 04, 2015 at 01:36:26PM +0200, Christoph Hellwig wrote:
> On Sun, Aug 02, 2015 at 10:58:22PM -0700, Ming Lin wrote:
> > I think the important thing is the late splitting for regular bio.
> > For discard/write_same bio, how about just don't do late splitting?
> 
> I'd hate having to special case them even more.  Especially as the
> discard splitting is nasty and we really don't want to send giant
> discards by default anyway (see Jens' patches to limit discard size
> by default).

Why is it that we don't want to send giant discards? Is it a latency issue?
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