From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752870AbcERJEH (ORCPT ); Wed, 18 May 2016 05:04:07 -0400 Received: from a.ns.miles-group.at ([95.130.255.143]:11949 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752791AbcERJED (ORCPT ); Wed, 18 May 2016 05:04:03 -0400 Subject: Re: UBIFS and page migration (take 3) To: Vlastimil Babka , Christoph Hellwig References: <1462974823-3168-1-git-send-email-richard@nod.at> <20160512114948.GA25113@infradead.org> <5739C0C1.1090907@nod.at> <5739C53B.1010700@suse.cz> <573B0009.3070004@nod.at> Cc: linux-fsdevel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, boris.brezillon@free-electrons.com, maxime.ripard@free-electrons.com, david@sigma-star.at, david@fromorbit.com, dedekind1@gmail.com, alex@nextthing.co, akpm@linux-foundation.org, sasha.levin@oracle.com, iamjoonsoo.kim@lge.com, rvaswani@codeaurora.org, tony.luck@intel.com, shailendra.capricorn@gmail.com, kirill.shutemov@linux.intel.com, hughd@google.com, mgorman@techsingularity.net From: Richard Weinberger Message-ID: <573C2FEF.6050500@nod.at> Date: Wed, 18 May 2016 11:03:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.1 MIME-Version: 1.0 In-Reply-To: <573B0009.3070004@nod.at> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 17.05.2016 um 13:27 schrieb Richard Weinberger: > Vlastimil, > > Am 16.05.2016 um 15:03 schrieb Vlastimil Babka: >> On 05/16/2016 02:44 PM, Richard Weinberger wrote: >>> MM folks, do we have a way to force page migration? >> >> On NUMA we have migrate_pages(2). > > Doesn't this only migrate process (user) pages? > AFAIK we need a way to force migration of pages which > are in the page cache. While migrate_pages(2) does not seem to hit the ->migratepage() function, echo 1 > /proc/sys/vm/compact_memory does. Thanks Vlastimil for pointing me in the right direction! Just reproduce the issue on UBIFS in a KVM guest and a simulated NAND. :-) Let's see whether I can come up with a generic test. Thanks, //richard