From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-fsdevel-owner@vger.kernel.org>
Date: Fri, 10 Feb 2017 09:58:52 -0800
From: Matthew Wilcox <willy@infradead.org>
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
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>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
In-Reply-To: <20170126115819.58875-18-kirill.shutemov@linux.intel.com>
Sender: linux-fsdevel-owner@vger.kernel.org
List-ID: <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>