Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033005AbbKEIJD (ORCPT ); Thu, 5 Nov 2015 03:09:03 -0500 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:39466 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030947AbbKEIJB (ORCPT ); Thu, 5 Nov 2015 03:09:01 -0500 X-Original-SENDERIP: 156.147.1.151 X-Original-MAILFROM: iamjoonsoo.kim@lge.com X-Original-SENDERIP: 10.177.222.138 X-Original-MAILFROM: iamjoonsoo.kim@lge.com Date: Thu, 5 Nov 2015 17:09:10 +0900 From: Joonsoo Kim To: Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Minchan Kim , Sasha Levin , "Kirill A. Shutemov" , Mel Gorman Subject: Re: [PATCH 1/5] mm, page_owner: print migratetype of a page, not pageblock Message-ID: <20151105080910.GA25938@js1304-P5Q-DELUXE> References: <1446649261-27122-1-git-send-email-vbabka@suse.cz> <1446649261-27122-2-git-send-email-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1446649261-27122-2-git-send-email-vbabka@suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1966 Lines: 49 On Wed, Nov 04, 2015 at 04:00:57PM +0100, Vlastimil Babka wrote: > The information in /sys/kernel/debug/page_owner includes the migratetype > declared during the page allocation via gfp_flags. This is also checked against > the pageblock's migratetype, and reported as Fallback allocation if these two > differ (although in fact fallback allocation is not the only reason why they > can differ). > > However, the migratetype actually printed is the one of the pageblock, not of > the page itself, so it's the same for all pages in the pageblock. This is > apparently a bug, noticed when working on other page_owner improvements. Fixed. We can guess page migratetype through gfp_mask output although it isn't easy task for now. But, there is no way to know pageblock migratetype. I used this to know how memory is fragmented. Thanks. > > Signed-off-by: Vlastimil Babka > --- > mm/page_owner.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_owner.c b/mm/page_owner.c > index 983c3a1..a9f16b8 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -113,7 +113,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, > "PFN %lu Block %lu type %d %s Flags %s%s%s%s%s%s%s%s%s%s%s%s\n", > pfn, > pfn >> pageblock_order, > - pageblock_mt, > + page_mt, > pageblock_mt != page_mt ? "Fallback" : " ", > PageLocked(page) ? "K" : " ", > PageError(page) ? "E" : " ", > -- > 2.6.2 > > -- > 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 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/