Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755514Ab3IYXTt (ORCPT ); Wed, 25 Sep 2013 19:19:49 -0400 Received: from e23smtp09.au.ibm.com ([202.81.31.142]:42780 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755475Ab3IYXTr (ORCPT ); Wed, 25 Sep 2013 19:19:47 -0400 From: "Srivatsa S. Bhat" Subject: [RFC PATCH v4 08/40] mm: Use the correct migratetype during buddy merging 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 Date: Thu, 26 Sep 2013 04:45:28 +0530 Message-ID: <20130925231526.26184.60112.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> 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: 13092523-3568-0000-0000-0000044C5359 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1488 Lines: 42 While merging buddy free pages of a given order to make a higher order page, the buddy allocator might coalesce pages belonging to *two* *different* migratetypes of that order! So, don't assume that both the buddies come from the same freelist; instead, explicitly find out the migratetype info of the buddy page and use it while merging the buddies. Also, set the freepage migratetype of the buddy to the new one. Signed-off-by: Srivatsa S. Bhat --- mm/page_alloc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e31daf4..c40715c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -685,10 +685,14 @@ static inline void __free_one_page(struct page *page, __mod_zone_freepage_state(zone, 1 << order, migratetype); } else { + int mt; + area = &zone->free_area[order]; - del_from_freelist(buddy, &area->free_list[migratetype]); + mt = get_freepage_migratetype(buddy); + del_from_freelist(buddy, &area->free_list[mt]); area->nr_free--; rmv_page_order(buddy); + set_freepage_migratetype(buddy, migratetype); } combined_idx = buddy_idx & page_idx; page = page + (combined_idx - page_idx); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/