From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f170.google.com (mail-pd0-f170.google.com [209.85.192.170]) by kanga.kvack.org (Postfix) with ESMTP id 875926B0087 for ; Wed, 25 Sep 2013 19:24:10 -0400 (EDT) Received: by mail-pd0-f170.google.com with SMTP id x10so327508pdj.1 for ; Wed, 25 Sep 2013 16:24:10 -0700 (PDT) Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 26 Sep 2013 04:53:52 +0530 Received: from d28relay01.in.ibm.com (d28relay01.in.ibm.com [9.184.220.58]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id AA657125803F for ; Thu, 26 Sep 2013 04:54:01 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r8PNQ5e729622396 for ; Thu, 26 Sep 2013 04:56:05 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r8PNNlwa028866 for ; Thu, 26 Sep 2013 04:53:48 +0530 From: "Srivatsa S. Bhat" Subject: [RFC PATCH v4 26/40] mm: Connect Page Allocator(PA) to Region Allocator(RA); add PA <= RA flow Date: Thu, 26 Sep 2013 04:49:41 +0530 Message-ID: <20130925231939.26184.88534.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> References: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, mgorman@suse.de, dave@sr71.net, hannes@cmpxchg.org, tony.luck@intel.com, matthew.garrett@nebula.com, riel@redhat.com, arjan@linux.intel.com, srinivas.pandruvada@linux.intel.com, willy@linux.intel.com, kamezawa.hiroyu@jp.fujitsu.com, lenb@kernel.org, rjw@sisk.pl Cc: gargankita@gmail.com, paulmck@linux.vnet.ibm.com, svaidy@linux.vnet.ibm.com, andi@firstfloor.org, isimatu.yasuaki@jp.fujitsu.com, santosh.shilimkar@ti.com, kosaki.motohiro@gmail.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Now that we have built up an infrastructure that forms a "Memory Region Allocator", connect it with the page allocator. To entities requesting memory, the page allocator will function as a front-end, whereas the region allocator will act as a back-end to the page allocator. (Analogy: page allocator is like free cash, whereas region allocator is like a bank). Implement the flow of freepages from the region allocator to the page allocator. When __rmqueue_smallest() comes out empty handed, try to get freepages from the region allocator. If that fails, only then fallback to an allocation from a different migratetype. This helps significantly in avoiding mixing of allocations of different migratetypes in a single region. Thus it helps in keeping entire memory regions homogeneous with respect to the type of allocations. Simplification: We assume that the freepages of a memory region can be completely represented by a set of MAX_ORDER-1 pages. That is, we only need to consider the buddy freelists corresponding to MAX_ORDER-1, while interacting with the region allocator. Furthermore, we assume that pageblock_order == MAX_ORDER-1. (These assumptions are used to ease the implementation, so that one can quickly evaluate the benefits of the overall design without getting bogged down by too many corner cases and constraints. Of course future implementations will handle more scenarios and will have reduced dependence on such simplifying assumptions.) Signed-off-by: Srivatsa S. Bhat --- mm/page_alloc.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d08bc91..0d73134 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1703,10 +1703,18 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order, { struct page *page; -retry_reserve: +retry: page = __rmqueue_smallest(zone, order, migratetype); if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { + + /* + * Try to get a region from the region allocator before falling + * back to an allocation from a different migratetype. + */ + if (!del_from_region_allocator(zone, MAX_ORDER-1, migratetype)) + goto retry; + page = __rmqueue_fallback(zone, order, migratetype); /* @@ -1716,7 +1724,7 @@ retry_reserve: */ if (!page) { migratetype = MIGRATE_RESERVE; - goto retry_reserve; + goto retry; } } -- 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