From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932284AbcEFRdw (ORCPT ); Fri, 6 May 2016 13:33:52 -0400 Received: from mail-lf0-f42.google.com ([209.85.215.42]:35531 "EHLO mail-lf0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932215AbcEFRdu (ORCPT ); Fri, 6 May 2016 13:33:50 -0400 Date: Fri, 6 May 2016 20:33:47 +0300 From: "Kirill A. Shutemov" To: Andrea Arcangeli Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alex Williamson Subject: Re: [PATCH 3/3] mm: thp: split_huge_pmd_address() comment improvement Message-ID: <20160506173347.GB9879@node.shutemov.name> References: <1462547040-1737-1-git-send-email-aarcange@redhat.com> <1462547040-1737-4-git-send-email-aarcange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1462547040-1737-4-git-send-email-aarcange@redhat.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 06, 2016 at 05:04:00PM +0200, Andrea Arcangeli wrote: > Comment is partly wrong, this improves it by including the case of > split_huge_pmd_address() called by try_to_unmap_one if > TTU_SPLIT_HUGE_PMD is set. > > Signed-off-by: Andrea Arcangeli Acked-by: Kirill A. Shutemov > --- > mm/huge_memory.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 9086793..1fbe13d 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -3031,8 +3031,10 @@ void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address, > return; > > /* > - * Caller holds the mmap_sem write mode, so a huge pmd cannot > - * materialize from under us. > + * Caller holds the mmap_sem write mode or the anon_vma lock, > + * so a huge pmd cannot materialize from under us (khugepaged > + * holds both the mmap_sem write mode and the anon_vma lock > + * write mode). > */ > __split_huge_pmd(vma, pmd, address, freeze); > } -- Kirill A. Shutemov