Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754579Ab1EANTu (ORCPT ); Sun, 1 May 2011 09:19:50 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:34180 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751293Ab1EANTr (ORCPT ); Sun, 1 May 2011 09:19:47 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Minchan Kim Subject: Re: [RFC 5/8] compaction: remove active list counting Cc: kosaki.motohiro@jp.fujitsu.com, Mel Gorman , Andrew Morton , linux-mm , LKML , Christoph Lameter , Johannes Weiner , KAMEZAWA Hiroyuki , Rik van Riel , Andrea Arcangeli In-Reply-To: References: <20110428105027.GT4658@suse.de> Message-Id: <20110501222117.75E8.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Mailer: Becky! ver. 2.56.05 [ja] Date: Sun, 1 May 2011 22:19:45 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1873 Lines: 47 > On Thu, Apr 28, 2011 at 7:50 PM, Mel Gorman wrote: > > On Wed, Apr 27, 2011 at 01:25:22AM +0900, Minchan Kim wrote: > >> acct_isolated of compaction uses page_lru_base_type which returns only > >> base type of LRU list so it never returns LRU_ACTIVE_ANON or LRU_ACTIVE_FILE. > >> So it's pointless to add lru[LRU_ACTIVE_[ANON|FILE]] to get sum. > >> > >> Cc: KOSAKI Motohiro > >> Cc: Mel Gorman > >> Cc: Rik van Riel > >> Cc: Andrea Arcangeli > >> Signed-off-by: Minchan Kim > > > > hmm, isolate_migratepages() is doing a linear scan of PFNs and is > > calling __isolate_lru_page(..ISOLATE_BOTH..). Using page_lru_base_type > > happens to work because we're only interested in the number of isolated > > pages and your patch still covers that. Using page_lru might be more > > accurate in terms of accountancy but does not seem necessary. > > True. > > > > > Adding a comment explaining why we account for it as inactive and why > > that's ok would be nice although I admit this is something I should have > > done when acct_isolated() was introduced. > > When Kame pointed out comment, I wanted to avoid unnecessary comment > so decided changing it with page_lru although it adds overhead a > little bit. But Hannes, you and maybe Kame don't want it. I don't mind > adding comment. > Okay. fix it in next version. Or unsigned int count[2]; list_for_each_entry(page, &cc->migratepages, lru) { count[page_is_file_cache(page)]++; } is also clear to me. -- 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/