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Date: Fri, 10 Feb 2017 09:58:52 -0800
From: Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCHv6 17/37] fs: make block_read_full_page() be able to read
 huge page
Message-ID: <20170210175852.GE2267@bombadil.infradead.org>
References: <20170126115819.58875-1-kirill.shutemov@linux.intel.com>
 <20170126115819.58875-18-kirill.shutemov@linux.intel.com>
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In-Reply-To: <20170126115819.58875-18-kirill.shutemov@linux.intel.com>
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To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>, Andreas Dilger <adilger.kernel@dilger.ca>, Jan Kara <jack@suse.com>, Andrew Morton <akpm@linux-foundation.org>, Alexander Viro <viro@zeniv.linux.org.uk>, Hugh Dickins <hughd@google.com>, Andrea Arcangeli <aarcange@redhat.com>, Dave Hansen <dave.hansen@intel.com>, Vlastimil Babka <vbabka@suse.cz>, Ross Zwisler <ross.zwisler@linux.intel.com>, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org

On Thu, Jan 26, 2017 at 02:57:59PM +0300, Kirill A. Shutemov wrote:
> The approach is straight-forward: for compound pages we read out whole
> huge page.

Ouch.  bufferheads must die ;-)

> For huge page we cannot have array of buffer head pointers on stack --
> it's 4096 pointers on x86-64 -- 'arr' is allocated with kmalloc() for
> huge pages.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>

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