From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f42.google.com (mail-pa0-f42.google.com [209.85.220.42]) by kanga.kvack.org (Postfix) with ESMTP id D9D9A6B0035 for ; Mon, 3 Feb 2014 20:20:49 -0500 (EST) Received: by mail-pa0-f42.google.com with SMTP id kl14so7815299pab.15 for ; Mon, 03 Feb 2014 17:20:49 -0800 (PST) Received: from mail-pb0-x22d.google.com (mail-pb0-x22d.google.com [2607:f8b0:400e:c01::22d]) by mx.google.com with ESMTPS id ek3si22520650pbd.55.2014.02.03.17.20.48 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 03 Feb 2014 17:20:48 -0800 (PST) Received: by mail-pb0-f45.google.com with SMTP id un15so7784139pbc.32 for ; Mon, 03 Feb 2014 17:20:48 -0800 (PST) Date: Mon, 3 Feb 2014 17:20:46 -0800 (PST) From: David Rientjes Subject: [patch] mm, compaction: avoid isolating pinned pages fix In-Reply-To: <20140204000237.GA17331@lge.com> Message-ID: References: <20140203095329.GH6732@suse.de> <20140204000237.GA17331@lge.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Mel Gorman , Andrew Morton , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Tue, 4 Feb 2014, Joonsoo Kim wrote: > I think that you need more code to skip this type of page correctly. > Without page_mapped() check, this code makes migratable pages be skipped, > since if page_mapped() case, page_count() may be more than zero. > > So I think that you need following change. > > (!page_mapping(page) && !page_mapped(page) && page_count(page)) > These pages returned by get_user_pages() will have a mapcount of 1 so this wouldn't actually fix the massive lock contention. page_mapping() is only going to be NULL for pages off the lru like these are for PAGE_MAPPING_ANON. -- 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