From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCHv4 18/43] block: define BIO_MAX_PAGES to HPAGE_PMD_NR if
 huge page cache enabled
Date: Wed, 26 Oct 2016 00:36:48 -0700
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Cc: Andreas Dilger <adilger@dilger.ca>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        Christoph Hellwig <hch@infradead.org>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Theodore Ts'o <tytso@mit.edu>,
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        Andrew Morton <akpm@linux-foundation.org>,
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        Andrea Arcangeli <aarcange@redhat.com>,
        Dave Hansen <dave.hansen@intel.com>,
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        Matthew Wilcox <willy@infradead.org>,
        Ross Zwisler <ross.zwisler@linux.intel.com>,
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        Linux FS Devel <linux-fsdevel@vger.kernel.org>,
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To: Ming Lei <tom.leiming@gmail.com>
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On Wed, Oct 26, 2016 at 03:30:05PM +0800, Ming Lei wrote:
> I am preparing for the multipage bvec support[1], and once it is ready the
> default 256 bvecs should be enough for normal cases.

Yes, multipage bvecs are defintively the way to got to efficiently
support I/O on huge pages.