Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759273AbYLLRhn (ORCPT ); Fri, 12 Dec 2008 12:37:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757237AbYLLRhd (ORCPT ); Fri, 12 Dec 2008 12:37:33 -0500 Received: from extu-mxob-2.symantec.com ([216.10.194.135]:57524 "EHLO extu-mxob-2.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756799AbYLLRhc (ORCPT ); Fri, 12 Dec 2008 12:37:32 -0500 Date: Fri, 12 Dec 2008 17:37:48 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@blonde.anvils To: Rik van Riel cc: KOSAKI Motohiro , Jens Axboe , Jean Delvare , Trond Myklebust , LKML Subject: Re: [PATCH] block: Fix LSF default inconsistency In-Reply-To: <494292D4.6090302@redhat.com> Message-ID: References: <20081211202923.330F.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20081211113646.GI23742@kernel.dk> <20081211204006.3312.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20081212075844.GH23742@kernel.dk> <49426C16.6040108@redhat.com> <2f11576a0812120711l130e07c3x94ff3b1e64959edf@mail.gmail.com> <494292D4.6090302@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1352 Lines: 33 On Fri, 12 Dec 2008, Rik van Riel wrote: > Hugh Dickins wrote: > > On Sat, 13 Dec 2008, KOSAKI Motohiro wrote: > > > > > To move mlocked file cache page to unevictable list is useful although > > > swapless embedded device. > > > > Yes, I don't understand why Rik suggested CONFIG_SWAP for it either. > On swapless systems (with CONFIG_SWAP=n), we never scan > the anon lists, so we do not need to split out the mlocked pages from > the anon pages. > > On a system with swap, we want to split out the mlocked pages > so that scan balancing always works right. So whenever > CONFIG_SWAP is on, we want CONFIG_UNEVICTABLE_LRU > to be on as well. > > That means we can replace CONFIG_UNEVICTABLE_LRU > with CONFIG_SWAP throughout the code, and get a kernel > with the desired behaviour either way. Sorry, I'm still puzzled: I thought the unevictable lru was for shared file pages as well as for anon pages? Of course I agree with you over the anons (and shm and tmpfs get counted along with the anons in this context), but wouldn't we still need an unevictable lru for mlocked shared file pages? Hugh -- 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/