From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f41.google.com (mail-pb0-f41.google.com [209.85.160.41]) by kanga.kvack.org (Postfix) with ESMTP id 264216B0031 for ; Mon, 16 Jun 2014 21:00:30 -0400 (EDT) Received: by mail-pb0-f41.google.com with SMTP id ma3so5075021pbc.28 for ; Mon, 16 Jun 2014 18:00:29 -0700 (PDT) Received: from mail-pa0-x229.google.com (mail-pa0-x229.google.com [2607:f8b0:400e:c03::229]) by mx.google.com with ESMTPS id zn10si15426615pac.99.2014.06.16.18.00.28 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 16 Jun 2014 18:00:29 -0700 (PDT) Received: by mail-pa0-f41.google.com with SMTP id fb1so2614469pad.14 for ; Mon, 16 Jun 2014 18:00:28 -0700 (PDT) Date: Mon, 16 Jun 2014 17:59:07 -0700 (PDT) From: Hugh Dickins Subject: Re: [PATCH] hugetlb: fix copy_hugetlb_page_range() to handle migration/hwpoisoned entry In-Reply-To: <20140616195950.GA21801@nhori.bos.redhat.com> Message-ID: References: <1402081620-1247-1-git-send-email-n-horiguchi@ah.jp.nec.com> <20140616195950.GA21801@nhori.bos.redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Hugh Dickins , Andrew Morton , Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Mon, 16 Jun 2014, Naoya Horiguchi wrote: > On Sun, Jun 15, 2014 at 05:19:29PM -0700, Hugh Dickins wrote: > > > > Hold on, that restriction of hugepage migration was marked for stable > > 3.12+, whereas this is marked for stable 2.6.36+ (a glance at my old > > trees suggests 2.6.37+, but you may know better - perhaps hugepage > > migration got backported to 2.6.36-stable, though hardly seems > > stable material). > > Sorry, I misinterpreted one thing. > I thought hugepage migration was merged at 2.6.36 because git-describe > shows v2.6.36-rc7-73-g290408d4a2 for commit 290408d4a2 "hugetlb: hugepage > migration core." But actually that's merged at commit f1ebdd60cc, or > v2.6.36-5792-gf1ebdd60cc73. So this is 2.6.37 stuff. > > Originally hugepage migration was used only for soft offlining in > mm/memory-failure.c which is available only in x86_64, so we implicitly > assumed that hugepage migration was restricted to x86_64. > At 3.12, hugepage migration became available for numa APIs like mbind(), > which are used for other architectures, so the restriction with > hugepage_migration_supported() became necessary since then. > This is the reason why the disablement was marked for 3.12+. > This patch are helpful before extension in 3.12, so it should be marked 2.6.37+. That all makes sense to me now: thanks a lot for explaining the history. Hugh -- 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