From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx206.postini.com [74.125.245.206]) by kanga.kvack.org (Postfix) with SMTP id 1CAD86B0033 for ; Mon, 10 Jun 2013 13:39:09 -0400 (EDT) From: "Kirill A. Shutemov" In-Reply-To: <51B2029A.8050504@sr71.net> References: <1368321816-17719-1-git-send-email-kirill.shutemov@linux.intel.com> <1368321816-17719-15-git-send-email-kirill.shutemov@linux.intel.com> <519BD595.5040405@sr71.net> <20130528122812.0D624E0090@blue.fi.intel.com> <20130607151025.241EFE0090@blue.fi.intel.com> <51B2029A.8050504@sr71.net> Subject: Re: [PATCHv4 14/39] thp, mm: rewrite delete_from_page_cache() to support huge pages Content-Transfer-Encoding: 7bit Message-Id: <20130610174146.8C1CFE0090@blue.fi.intel.com> Date: Mon, 10 Jun 2013 20:41:46 +0300 (EEST) Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: "Kirill A. Shutemov" , Andrea Arcangeli , Andrew Morton , Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Dave Hansen wrote: > On 06/07/2013 08:10 AM, Kirill A. Shutemov wrote: > > + /* > > + * When we add a huge page to page cache we take only reference to head > > + * page, but on split we need to take addition reference to all tail > > + * pages since they are still in page cache after splitting. > > + */ > > + init_tail_refcount = PageAnon(page) ? 0 : 1; > > What's the "init" for in the name? initial_tail_refcount? > In add_to_page_cache_locked() in patch 12/39, you do > > + spin_lock_irq(&mapping->tree_lock); > > + for (i = 0; i < nr; i++) { > > + page_cache_get(page + i); > > That looks to me to be taking references to the tail pages. What gives? :) The point is to drop this from add_to_page_cache_locked() and make distribution on split. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org