Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752517AbcD1TMl (ORCPT ); Thu, 28 Apr 2016 15:12:41 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45892 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750809AbcD1TMj (ORCPT ); Thu, 28 Apr 2016 15:12:39 -0400 Date: Thu, 28 Apr 2016 12:12:38 -0700 From: Andrew Morton To: Jonathan Corbet Cc: Eric Engestrom , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Rik van Riel , Vlastimil Babka , Ebru Akagunduz , Mel Gorman , linux-doc@vger.kernel.org Subject: Re: [PATCH 39/41] Documentation: vm: fix spelling mistakes Message-Id: <20160428121238.15472b6fdd30758c79d4d2b0@linux-foundation.org> In-Reply-To: <20160428074607.5ae199e5@lwn.net> References: <1461543878-3639-1-git-send-email-eric@engestrom.ch> <1461566229-4717-1-git-send-email-eric@engestrom.ch> <1461566229-4717-13-git-send-email-eric@engestrom.ch> <20160428073143.64f8a2ae@lwn.net> <20160428074607.5ae199e5@lwn.net> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2990 Lines: 71 On Thu, 28 Apr 2016 07:46:07 -0600 Jonathan Corbet wrote: > On Thu, 28 Apr 2016 07:31:43 -0600 > Jonathan Corbet wrote: > > > On Mon, 25 Apr 2016 07:37:05 +0100 > > Eric Engestrom wrote: > > > > > Documentation/vm/transhuge.txt | 6 +++--- > > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > Applied to the docs tree, thanks. > > Actually, I've just unapplied this one; it conflicts against changes in > Andrew's tree and, thus, linux-next. Andrew, maybe you'd like to take it > on top of what you have now? Sure. That Documentation/vm/transhuge.txt paragraph isn't in great shape so I gave it some extra help. From: Eric Engestrom Subject: Documentation: vm: fix spelling mistakes Signed-off-by: Eric Engestrom Cc: Jonathan Corbet Signed-off-by: Andrew Morton --- Documentation/vm/transhuge.txt | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff -puN Documentation/vm/transhuge.txt~documentation-vm-fix-spelling-mistakes Documentation/vm/transhuge.txt --- a/Documentation/vm/transhuge.txt~documentation-vm-fix-spelling-mistakes +++ a/Documentation/vm/transhuge.txt @@ -340,7 +340,7 @@ unaffected. libhugetlbfs will also work == Graceful fallback == -Code walking pagetables but unware about huge pmds can simply call +Code walking pagetables but unaware about huge pmds can simply call split_huge_pmd(vma, pmd, addr) where the pmd is the one returned by pmd_offset. It's trivial to make the code transparent hugepage aware by just grepping for "pmd_offset" and adding split_huge_pmd where @@ -414,7 +414,7 @@ tracking. The alternative is alter ->_ma map/unmap of the whole compound page. We set PG_double_map when a PMD of the page got split for the first time, -but still have PMD mapping. The addtional references go away with last +but still have PMD mapping. The additional references go away with last compound_mapcount. split_huge_page internally has to distribute the refcounts in the head @@ -432,10 +432,10 @@ page->_mapcount. We safe against physical memory scanners too: the only legitimate way scanner can get reference to a page is get_page_unless_zero(). -All tail pages has zero ->_refcount until atomic_add(). It prevent scanner -from geting reference to tail page up to the point. After the atomic_add() -we don't care about ->_refcount value. We already known how many references -with should uncharge from head page. +All tail pages have zero ->_refcount until atomic_add(). This prevents the +scanner from getting a reference to the tail page up to that point. After the +atomic_add() we don't care about the ->_refcount value. We already known how +many references should be uncharged from the head page. For head page get_page_unless_zero() will succeed and we don't mind. It's clear where reference should go after split: it will stay on head page. _