From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756546Ab3H3N1r (ORCPT ); Fri, 30 Aug 2013 09:27:47 -0400 Received: from e35.co.us.ibm.com ([32.97.110.153]:34291 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752733Ab3H3N1o (ORCPT ); Fri, 30 Aug 2013 09:27:44 -0400 From: "Srivatsa S. Bhat" Subject: [RFC PATCH v3 30/35] mm: Provide a mechanism to check if a given page is in the region allocator To: akpm@linux-foundation.org, mgorman@suse.de, hannes@cmpxchg.org, tony.luck@intel.com, matthew.garrett@nebula.com, dave@sr71.net, 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 Date: Fri, 30 Aug 2013 18:53:31 +0530 Message-ID: <20130830132329.4947.99949.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130830131221.4947.99764.stgit@srivatsabhat.in.ibm.com> References: <20130830131221.4947.99764.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13083013-4834-0000-0000-00000A99548D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the introduction of the region allocator, a freepage can be either in one of the buddy freelists or in the region allocator. In cases where we want to move freepages to a given migratetype's freelists, we will need to know where they were originally located. So provide a helper to distinguish whether the freepage resides in the region allocator or the buddy freelists. Signed-off-by: Srivatsa S. Bhat --- mm/page_alloc.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a62730b..3f49ca8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1047,6 +1047,37 @@ static int del_from_region_allocator(struct zone *zone, unsigned int order, } /* + * Return 1 if the page is in the region allocator, else return 0 + * (which usually means that the page is in the buddy freelists). + */ +static int page_in_region_allocator(struct page *page) +{ + struct region_allocator *reg_alloc; + struct free_area_region *reg_area; + int order, region_id; + + /* We keep only MAX_ORDER-1 pages in the region allocator */ + order = page_order(page); + if (order != MAX_ORDER-1) + return 0; + + /* + * It is sufficient to check if (any of) the pages belonging to + * that region are in the region allocator, because a page resides + * in the region allocator if and only if all the pages of that + * region are also in the region allocator. + */ + region_id = page_zone_region_id(page); + reg_alloc = &page_zone(page)->region_allocator; + reg_area = ®_alloc->region[region_id].region_area[order]; + + if (reg_area->nr_free) + return 1; + + return 0; +} + +/* * Freeing function for a buddy system allocator. * * The concept of a buddy system is to maintain direct-mapped table From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx142.postini.com [74.125.245.142]) by kanga.kvack.org (Postfix) with SMTP id 3AF1F6B009A for ; Fri, 30 Aug 2013 09:28:32 -0400 (EDT) Received: from /spool/local by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 30 Aug 2013 07:28:31 -0600 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id A7AD53E40026 for ; Fri, 30 Aug 2013 07:27:29 -0600 (MDT) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r7UDRTo6210556 for ; Fri, 30 Aug 2013 07:27:29 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r7UDRS39014114 for ; Fri, 30 Aug 2013 07:27:29 -0600 From: "Srivatsa S. Bhat" Subject: [RFC PATCH v3 30/35] mm: Provide a mechanism to check if a given page is in the region allocator Date: Fri, 30 Aug 2013 18:53:31 +0530 Message-ID: <20130830132329.4947.99949.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130830131221.4947.99764.stgit@srivatsabhat.in.ibm.com> References: <20130830131221.4947.99764.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, hannes@cmpxchg.org, tony.luck@intel.com, matthew.garrett@nebula.com, dave@sr71.net, 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 With the introduction of the region allocator, a freepage can be either in one of the buddy freelists or in the region allocator. In cases where we want to move freepages to a given migratetype's freelists, we will need to know where they were originally located. So provide a helper to distinguish whether the freepage resides in the region allocator or the buddy freelists. Signed-off-by: Srivatsa S. Bhat --- mm/page_alloc.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a62730b..3f49ca8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1047,6 +1047,37 @@ static int del_from_region_allocator(struct zone *zone, unsigned int order, } /* + * Return 1 if the page is in the region allocator, else return 0 + * (which usually means that the page is in the buddy freelists). + */ +static int page_in_region_allocator(struct page *page) +{ + struct region_allocator *reg_alloc; + struct free_area_region *reg_area; + int order, region_id; + + /* We keep only MAX_ORDER-1 pages in the region allocator */ + order = page_order(page); + if (order != MAX_ORDER-1) + return 0; + + /* + * It is sufficient to check if (any of) the pages belonging to + * that region are in the region allocator, because a page resides + * in the region allocator if and only if all the pages of that + * region are also in the region allocator. + */ + region_id = page_zone_region_id(page); + reg_alloc = &page_zone(page)->region_allocator; + reg_area = ®_alloc->region[region_id].region_area[order]; + + if (reg_area->nr_free) + return 1; + + return 0; +} + +/* * Freeing function for a buddy system allocator. * * The concept of a buddy system is to maintain direct-mapped table -- 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