From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753189Ab3LMREx (ORCPT ); Fri, 13 Dec 2013 12:04:53 -0500 Received: from zene.cmpxchg.org ([85.214.230.12]:46618 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753122Ab3LMREw (ORCPT ); Fri, 13 Dec 2013 12:04:52 -0500 Date: Fri, 13 Dec 2013 12:04:43 -0500 From: Johannes Weiner To: Mel Gorman Cc: Andrew Morton , Dave Hansen , Rik van Riel , Linux-MM , LKML Subject: Re: [PATCH 7/7] mm: page_alloc: Default allow file pages to use remote nodes for fair allocation policy Message-ID: <20131213170443.GO22729@cmpxchg.org> References: <1386943807-29601-1-git-send-email-mgorman@suse.de> <1386943807-29601-8-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1386943807-29601-8-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 13, 2013 at 02:10:07PM +0000, Mel Gorman wrote: > Indications from Johannes that he wanted this. Needs some data and/or justification why > thrash protection needs it plus docs describing how MPOL_LOCAL is now different before > it should be considered finished. I do not necessarily agree this patch is necessary > but it's worth punting it out there for discussion and testing. I demonstrated enormous gains in the original submission of the fair allocation patch and your tests haven't really shown downsides to the cache-over-nodes portion of it. So I don't see why we should revert the cache-over-nodes fairness without any supporting data. Reverting cross-node fairness for anon and slab is a good idea. It was always about cache and the original patch was too broad stroked, but it doesn't invalidate everything it was about. I can see, however, that we might want to make this configurable, but I'm not eager on exporting user interfaces unless we have to. As the node-local fairness was never questioned by anybody, is it necessary to make it configurable? Shouldn't we be okay with just a single vm.pagecache_interleave (name by Rik) sysctl that defaults to 1 but allows users to go back to pagecache obeying mempolicy? > Not signed off > --- > mm/page_alloc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index bf49918..bce40c0 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1885,7 +1885,8 @@ unsigned __bitwise__ zone_distribute_mode __read_mostly; > #define DISTRIBUTE_STUPID_ANON (DISTRIBUTE_LOCAL_ANON|DISTRIBUTE_REMOTE_ANON) > #define DISTRIBUTE_STUPID_FILE (DISTRIBUTE_LOCAL_FILE|DISTRIBUTE_REMOTE_FILE) > #define DISTRIBUTE_STUPID_SLAB (DISTRIBUTE_LOCAL_SLAB|DISTRIBUTE_REMOTE_SLAB) > -#define DISTRIBUTE_DEFAULT (DISTRIBUTE_LOCAL_ANON|DISTRIBUTE_LOCAL_FILE|DISTRIBUTE_LOCAL_SLAB) > +#define DISTRIBUTE_DEFAULT (DISTRIBUTE_LOCAL_ANON|DISTRIBUTE_LOCAL_FILE|DISTRIBUTE_LOCAL_SLAB| \ > + DISTRIBUTE_REMOTE_FILE) > > /* Only these GFP flags are affected by the fair zone allocation policy */ > #define DISTRIBUTE_GFP_MASK ((GFP_MOVABLE_MASK|__GFP_PAGECACHE)) > -- > 1.8.4 > > -- > 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-bk0-f53.google.com (mail-bk0-f53.google.com [209.85.214.53]) by kanga.kvack.org (Postfix) with ESMTP id 845D86B0031 for ; Fri, 13 Dec 2013 12:04:52 -0500 (EST) Received: by mail-bk0-f53.google.com with SMTP id na10so1463032bkb.40 for ; Fri, 13 Dec 2013 09:04:51 -0800 (PST) Received: from zene.cmpxchg.org (zene.cmpxchg.org. [2a01:238:4224:fa00:ca1f:9ef3:caee:a2bd]) by mx.google.com with ESMTPS id tn6si591404bkb.156.2013.12.13.09.04.50 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Fri, 13 Dec 2013 09:04:51 -0800 (PST) Date: Fri, 13 Dec 2013 12:04:43 -0500 From: Johannes Weiner Subject: Re: [PATCH 7/7] mm: page_alloc: Default allow file pages to use remote nodes for fair allocation policy Message-ID: <20131213170443.GO22729@cmpxchg.org> References: <1386943807-29601-1-git-send-email-mgorman@suse.de> <1386943807-29601-8-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1386943807-29601-8-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , Dave Hansen , Rik van Riel , Linux-MM , LKML On Fri, Dec 13, 2013 at 02:10:07PM +0000, Mel Gorman wrote: > Indications from Johannes that he wanted this. Needs some data and/or justification why > thrash protection needs it plus docs describing how MPOL_LOCAL is now different before > it should be considered finished. I do not necessarily agree this patch is necessary > but it's worth punting it out there for discussion and testing. I demonstrated enormous gains in the original submission of the fair allocation patch and your tests haven't really shown downsides to the cache-over-nodes portion of it. So I don't see why we should revert the cache-over-nodes fairness without any supporting data. Reverting cross-node fairness for anon and slab is a good idea. It was always about cache and the original patch was too broad stroked, but it doesn't invalidate everything it was about. I can see, however, that we might want to make this configurable, but I'm not eager on exporting user interfaces unless we have to. As the node-local fairness was never questioned by anybody, is it necessary to make it configurable? Shouldn't we be okay with just a single vm.pagecache_interleave (name by Rik) sysctl that defaults to 1 but allows users to go back to pagecache obeying mempolicy? > Not signed off > --- > mm/page_alloc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index bf49918..bce40c0 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1885,7 +1885,8 @@ unsigned __bitwise__ zone_distribute_mode __read_mostly; > #define DISTRIBUTE_STUPID_ANON (DISTRIBUTE_LOCAL_ANON|DISTRIBUTE_REMOTE_ANON) > #define DISTRIBUTE_STUPID_FILE (DISTRIBUTE_LOCAL_FILE|DISTRIBUTE_REMOTE_FILE) > #define DISTRIBUTE_STUPID_SLAB (DISTRIBUTE_LOCAL_SLAB|DISTRIBUTE_REMOTE_SLAB) > -#define DISTRIBUTE_DEFAULT (DISTRIBUTE_LOCAL_ANON|DISTRIBUTE_LOCAL_FILE|DISTRIBUTE_LOCAL_SLAB) > +#define DISTRIBUTE_DEFAULT (DISTRIBUTE_LOCAL_ANON|DISTRIBUTE_LOCAL_FILE|DISTRIBUTE_LOCAL_SLAB| \ > + DISTRIBUTE_REMOTE_FILE) > > /* Only these GFP flags are affected by the fair zone allocation policy */ > #define DISTRIBUTE_GFP_MASK ((GFP_MOVABLE_MASK|__GFP_PAGECACHE)) > -- > 1.8.4 > > -- > 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 -- 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