From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f72.google.com (mail-lf0-f72.google.com [209.85.215.72]) by kanga.kvack.org (Postfix) with ESMTP id ED1D2828E1 for ; Wed, 22 Jun 2016 18:21:21 -0400 (EDT) Received: by mail-lf0-f72.google.com with SMTP id l184so43470353lfl.3 for ; Wed, 22 Jun 2016 15:21:21 -0700 (PDT) Received: from radon.swed.at (b.ns.miles-group.at. [95.130.255.144]) by mx.google.com with ESMTPS id x80si1393931wme.118.2016.06.22.15.21.20 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 22 Jun 2016 15:21:20 -0700 (PDT) Subject: Re: [PATCH 1/3] mm: Don't blindly assign fallback_migrate_page() References: <1466112375-1717-1-git-send-email-richard@nod.at> <1466112375-1717-2-git-send-email-richard@nod.at> <20160616161121.35ee5183b9ef9f7b7dcbc815@linux-foundation.org> From: Richard Weinberger Message-ID: <576B0F57.3030700@nod.at> Date: Thu, 23 Jun 2016 00:21:11 +0200 MIME-Version: 1.0 In-Reply-To: <20160616161121.35ee5183b9ef9f7b7dcbc815@linux-foundation.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, hannes@cmpxchg.org, mgorman@techsingularity.net, n-horiguchi@ah.jp.nec.com, mhocko@suse.com, kirill.shutemov@linux.intel.com, hughd@google.com, vbabka@suse.cz, adrian.hunter@intel.com, dedekind1@gmail.com, hch@infradead.org, linux-fsdevel@vger.kernel.org, boris.brezillon@free-electrons.com, maxime.ripard@free-electrons.com, david@sigma-star.at, david@fromorbit.com, alex@nextthing.co, sasha.levin@oracle.com, iamjoonsoo.kim@lge.com, rvaswani@codeaurora.org, tony.luck@intel.com, shailendra.capricorn@gmail.com Am 17.06.2016 um 01:11 schrieb Andrew Morton: > On Thu, 16 Jun 2016 23:26:13 +0200 Richard Weinberger wrote: > >> While block oriented filesystems use buffer_migrate_page() >> as page migration function other filesystems which don't >> implement ->migratepage() will automatically get fallback_migrate_page() >> assigned. fallback_migrate_page() is not as generic as is should >> be. Page migration is filesystem specific and a one-fits-all function >> is hard to achieve. UBIFS leaned this lection the hard way. >> It uses various page flags and fallback_migrate_page() does not >> handle these flags as UBIFS expected. >> >> To make sure that no further filesystem will get confused by >> fallback_migrate_page() disable the automatic assignment and >> allow filesystems to use this function explicitly if it is >> really suitable. > > hm, is there really much point in doing this? I assume it doesn't > actually affect any current filesystems? > > [2/3] is of course OK - please add it to the UBIFS tree. Pushed 2/3 and 3/3 into UBIFS next tree. Thanks, //richard -- 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