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To: Ming Lei <ming.lei@canonical.com>, Jens Axboe <axboe@fb.com>,
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From: Jens Axboe <axboe@kernel.dk>
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Date: Thu, 14 Apr 2016 08:11:03 -0600
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Cc: Christoph Hellwig <hch@infradead.org>, Jan Kara <jack@suse.cz>,
	Mike Snitzer <snitzer@redhat.com>,
	"open list:XFS FILESYSTEM" <xfs@oss.sgi.com>,
	linux-block@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
	Shaohua Li <shli@fb.com>, Tejun Heo <tj@kernel.org>,
	Keith Busch <keith.busch@intel.com>,
	Kent Overstreet <kent.overstreet@gmail.com>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	"open list:DRBD DRIVER" <drbd-dev@lists.linbit.com>
Subject: Re: [Drbd-dev] [PATCH v4 0/8] block: prepare for multipage bvecs
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On 04/14/2016 05:46 AM, Ming Lei wrote:
> Hi,
>
> Interests[1] have been shown in multipage bvecs, so this patchset
> try to prepare for the support and do two things:
>
> 1) the 1st 4 patches use bvec iterator to implement iterate_bvec(),
> then we can drop the non-standard way for iterating bvec, which
> can be thought as a good cleanup for lib/iov_iter.c
>
> 2) remove BIO_MAX_SECTORS & BIO_MAX_SIZE, and now there is only
> one user for each. Once multipage bvecs is introduced, one bio
> may hold lots of sectors, and we should always use sort of BIO_MAX_VECS
> which should be introduced in future and is similiar with current
> BIO_MAX_PAGES.
>
> xfstests(-a auto) have been run over ext4/xfs and no regression found
> by this patchset.

We've had too many disasters in the block layer the last few series, I'm 
making the 4.7 round a nice and small one. I don't mind taking prep 
patches for the multipage bvecs, if they are simple and clean, but 
that's about the extent of it.

Just a heads up.

-- 
Jens Axboe