From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 3A46A6B0047 for ; Sun, 10 May 2009 05:04:59 -0400 (EDT) Received: by yx-out-1718.google.com with SMTP id 36so1188641yxh.26 for ; Sun, 10 May 2009 02:05:02 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20090508230045.5346bd32@lxorguk.ukuu.org.uk> References: <20090430181340.6f07421d.akpm@linux-foundation.org> <20090501123541.7983a8ae.akpm@linux-foundation.org> <20090503031539.GC5702@localhost> <1241432635.7620.4732.camel@twins> <20090507121101.GB20934@localhost> <20090507151039.GA2413@cmpxchg.org> <20090507134410.0618b308.akpm@linux-foundation.org> <20090508081608.GA25117@localhost> <20090508125859.210a2a25.akpm@linux-foundation.org> <20090508230045.5346bd32@lxorguk.ukuu.org.uk> Date: Sun, 10 May 2009 17:59:17 +0900 Message-ID: <2f11576a0905100159m32c36a9ep9fb7cc5604c60b2@mail.gmail.com> Subject: Re: [PATCH -mm] vmscan: make mapped executable pages the first class citizen From: KOSAKI Motohiro Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Alan Cox Cc: Andrew Morton , Wu Fengguang , hannes@cmpxchg.org, peterz@infradead.org, riel@redhat.com, linux-kernel@vger.kernel.org, tytso@mit.edu, linux-mm@kvack.org, elladan@eskimo.com, npiggin@suse.de, cl@linux-foundation.org, minchan.kim@gmail.com List-ID: 2009/5/9 Alan Cox : >> The patch seems reasonable but the changelog and the (non-existent) >> design documentation could do with a touch-up. > > Is it right that I as a user can do things like mmap my database > PROT_EXEC to get better database numbers by making other > stuff swap first ? > > You seem to be giving everyone a "nice my process up" hack. How about this? if priority < DEF_PRIORITY-2, aggressive lumpy reclaim in shrink_inactive_list() already reclaim the active page forcely. then, this patch don't change kernel reclaim policy. anyway, user process non-changable preventing "nice my process up hack" seems makes sense to me. test result: echo 100 > /proc/sys/vm/dirty_ratio echo 100 > /proc/sys/vm/dirty_background_ratio run modified qsbench (use mmap(PROT_EXEC) instead malloc) active2active vs active2inactive ratio before 5:5 after 1:9 please don't ask performance number. I haven't reproduce Wu's patch improvemnt ;) Wu, What do you think? --- mm/vmscan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Index: b/mm/vmscan.c =================================================================== --- a/mm/vmscan.c 2009-05-10 02:40:01.000000000 +0900 +++ b/mm/vmscan.c 2009-05-10 03:33:30.000000000 +0900 @@ -1275,7 +1275,8 @@ static void shrink_active_list(unsigned struct address_space *mapping = page_mapping(page); pgmoved++; - if (mapping && test_bit(AS_EXEC, &mapping->flags)) { + if (mapping && (priority >= DEF_PRIORITY - 2) && + test_bit(AS_EXEC, &mapping->flags)) { pga2a++; list_add(&page->lru, &l_active); continue; -- 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