From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id D5B5082F64 for ; Thu, 5 Nov 2015 03:09:03 -0500 (EST) Received: by pasz6 with SMTP id z6so83410862pas.2 for ; Thu, 05 Nov 2015 00:09:03 -0800 (PST) Received: from lgeamrelo12.lge.com (LGEAMRELO12.lge.com. [156.147.23.52]) by mx.google.com with ESMTPS id b7si6420893pat.207.2015.11.05.00.09.01 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 05 Nov 2015 00:09:02 -0800 (PST) Date: Thu, 5 Nov 2015 17:09:10 +0900 From: Joonsoo Kim 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> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Minchan Kim , Sasha Levin , "Kirill A. Shutemov" , Mel Gorman 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, 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