From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx129.postini.com [74.125.245.129]) by kanga.kvack.org (Postfix) with SMTP id 571BD6B004D for ; Thu, 8 Mar 2012 21:07:26 -0500 (EST) Received: by iajr24 with SMTP id r24so2080509iaj.14 for ; Thu, 08 Mar 2012 18:07:25 -0800 (PST) Date: Thu, 8 Mar 2012 18:06:50 -0800 (PST) From: Hugh Dickins Subject: Re: [PATCH 3/7 v2] mm: rework __isolate_lru_page() file/anon filter In-Reply-To: <20120308143034.f3521b1e.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <20120229091547.29236.28230.stgit@zurg> <20120303091327.17599.80336.stgit@zurg> <20120308143034.f3521b1e.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Konstantin Khlebnikov , Andrew Morton , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, 8 Mar 2012, KAMEZAWA Hiroyuki wrote: > On Tue, 6 Mar 2012 19:22:21 -0800 (PST) > Hugh Dickins wrote: > > > > What does the compiler say (4.5.1 here, OPTIMIZE_FOR_SIZE off)? > > text data bss dec hex filename > > 17723 113 17 17853 45bd vmscan.o.0 > > 17671 113 17 17801 4589 vmscan.o.1 > > 17803 113 17 17933 460d vmscan.o.2 > > > > That suggests that your v2 is the worst and your v1 the best. > > Kame, can I persuade you to let the compiler decide on this? > > > > Hmm. How about Costa' proposal ? as > > int tmp_var = PageActive(page) ? ISOLATE_ACTIVE : ISOLATE_INACTIVE > if (!(mode & tmp_var)) > ret; Yes, that would have been a good compromise (given a better name than "tmp_var"!), I didn't realize that one was acceptable to you. But I see that Konstantin has been inspired by our disagreement to a more creative solution. I like very much the look of what he's come up with, but I'm still puzzling over why it barely makes any improvement to __isolate_lru_page(): seems significantly inferior (in code size terms) to his original (which I imagine Glauber's compromise would be equivalent to). At some point I ought to give up on niggling about this, but I haven't quite got there yet. Hugh -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org