Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758162AbZCWIoZ (ORCPT ); Mon, 23 Mar 2009 04:44:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757048AbZCWIoN (ORCPT ); Mon, 23 Mar 2009 04:44:13 -0400 Received: from cmpxchg.org ([85.214.51.133]:54634 "EHLO cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756102AbZCWIoM (ORCPT ); Mon, 23 Mar 2009 04:44:12 -0400 Date: Mon, 23 Mar 2009 09:42:54 +0100 From: Johannes Weiner To: KOSAKI Motohiro Cc: Minchan Kim , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Howells , Nick Piggin , Rik van Riel , Peter Zijlstra , Lee Schermerhorn Subject: Re: [patch 3/3] mm: keep pages from unevictable mappings off the LRU lists Message-ID: <20090323084254.GA1685@cmpxchg.org> References: <1237752784-1989-3-git-send-email-hannes@cmpxchg.org> <28c262360903221744r6d275294gdc8ad3a12b8c5361@mail.gmail.com> <20090323111615.69F3.A69D9226@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090323111615.69F3.A69D9226@jp.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1218 Lines: 29 On Mon, Mar 23, 2009 at 11:21:36AM +0900, KOSAKI Motohiro wrote: > > Hmm,, > > > > This patch is another thing unlike previous series patches. > > Firstly, It looked good to me. > > > > I think add_to_page_cache_lru have to become a fast path. > > But, how often would ramfs and shmem function be called ? > > > > I have a concern for this patch to add another burden. > > so, we need any numbers for getting pros and cons. > > > > Any thoughts ? > > this is the just reason why current code don't call add_page_to_unevictable_list(). > add_page_to_unevictable_list() don't use pagevec. it is needed for avoiding race. > > then, if readahead path (i.e. add_to_page_cache_lru()) use add_page_to_unevictable_list(), > it can cause zone->lru_lock contention storm. How is it different then shrink_page_list()? If readahead put a contiguous chunk of unevictable pages to the file lru, then shrink_page_list() will as well call add_page_to_unevictable_list() in a loop. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/