From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 363B86B00B9 for ; Mon, 23 Mar 2009 03:42:59 -0400 (EDT) Date: Mon, 23 Mar 2009 09:42:54 +0100 From: Johannes Weiner 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: owner-linux-mm@kvack.org 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 List-ID: 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, 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