From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753324Ab2CCJUM (ORCPT ); Sat, 3 Mar 2012 04:20:12 -0500 Received: from mail-bk0-f46.google.com ([209.85.214.46]:62183 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752725Ab2CCJUI (ORCPT ); Sat, 3 Mar 2012 04:20:08 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of koct9i@gmail.com designates 10.204.133.219 as permitted sender) smtp.mail=koct9i@gmail.com; dkim=pass header.i=koct9i@gmail.com Message-ID: <4F51E243.5050804@openvz.org> Date: Sat, 03 Mar 2012 13:20:03 +0400 From: Konstantin Khlebnikov User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.19) Gecko/20120201 Iceape/2.0.14 MIME-Version: 1.0 To: Hugh Dickins CC: Andrew Morton , Johannes Weiner , KAMEZAWA Hiroyuki , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 3/7] mm: rework __isolate_lru_page() file/anon filter References: <20120229090748.29236.35489.stgit@zurg> <20120229091547.29236.28230.stgit@zurg> <4F51D5FB.4050106@openvz.org> In-Reply-To: <4F51D5FB.4050106@openvz.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Konstantin Khlebnikov wrote: > Hugh Dickins wrote: >> On Wed, 29 Feb 2012, Konstantin Khlebnikov wrote: >> >>> This patch adds file/anon filter bits into isolate_mode_t, >>> this allows to simplify checks in __isolate_lru_page(). >>> >>> Signed-off-by: Konstantin Khlebnikov >> >> Almost-Acked-by: Hugh Dickins >> >> with one whitespace nit, and one functional addition requested. >> >> I'm perfectly happy with your :?s myself, but some people do dislike >> them. I'm happy with the switch alternative if it's as efficient: >> something that surprised me very much when trying to get convincing >> performance numbers for per-memcg per-zone lru_lock at home... >> >> ... __isolate_lru_page() featured astonishly high on the perf report >> of streaming from files on ext4 on /dev/ram0 to /dev/null, coming >> immediately below the obvious zeroing and copying: okay, the zeroing >> and copying were around 30% each, and __isolate_lru_page() down around >> 2% or below, but even so it seemed very odd that it should feature so >> high, and any optimizations to it very welcome - unless it was purely >> some bogus result. > > Actually ANON/FILE ACTIVE/INACTIVE checks does not required at non-lumpy reclaim > (all pages are picked from right lru list) and compaction (it does not care). > But seems like removing these two bit-checks cannot give noticeable performance gain. > > This patch can be postponed. It does not so important and > it does not share context with other patches in this set. Oops, no it cannot be dropped. Next patch "mm: push lru index into shrink_[in]active_list()" kills "file" variable in isolate_lru_pages(). I sent v2 for this patch only. > >> >>> --- >>> include/linux/mmzone.h | 4 ++++ >>> include/linux/swap.h | 2 +- >>> mm/compaction.c | 5 +++-- >>> mm/vmscan.c | 27 +++++++++++++-------------- >>> 4 files changed, 21 insertions(+), 17 deletions(-) >>> >>> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h >>> index eff4918..2fed935 100644 >>> --- a/include/linux/mmzone.h >>> +++ b/include/linux/mmzone.h >>> @@ -193,6 +193,10 @@ struct lruvec { >>> #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x8) >>> /* Isolate for asynchronous migration */ >>> #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x10) >>> +/* Isolate swap-backed pages */ >>> +#define ISOLATE_ANON ((__force isolate_mode_t)0x20) >>> +/* Isolate file-backed pages */ >>> +#define ISOLATE_FILE ((__force isolate_mode_t)0x40) >> >> From the patch you can see that the #defines above yours used a >> space where you have used a tab: better to use a space as above. >> >>> @@ -375,7 +376,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, >>> mode |= ISOLATE_ASYNC_MIGRATE; >>> >>> /* Try isolate the page */ >>> - if (__isolate_lru_page(page, mode, 0) != 0) >>> + if (__isolate_lru_page(page, mode) != 0) >>> continue; >> >> I thought you were missing something there, but no, that's rather >> the case you are simplifying. However... >> >>> diff --git a/mm/vmscan.c b/mm/vmscan.c >>> index af6cfe7..1b70338 100644 >>> --- a/mm/vmscan.c >>> +++ b/mm/vmscan.c >>> @@ -1520,6 +1511,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, >>> isolate_mode |= ISOLATE_UNMAPPED; >>> if (!sc->may_writepage) >>> isolate_mode |= ISOLATE_CLEAN; >>> + if (file) >>> + isolate_mode |= ISOLATE_FILE; >>> + else >>> + isolate_mode |= ISOLATE_ANON; >> >> Above here, under "if (sc->reclaim_mode& RECLAIM_MODE_LUMPYRECLAIM)", >> don't you need >> >> isolate_mode |= ISOLATE_ACTIVE | ISOLATE_FILE | ISOLATE_ANON; >> >> now to reproduce the same "all_lru_mode" behaviour as before? > > Yes, I missed this. Thanks. > >> >> 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