From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752496AbcGAIie (ORCPT ); Fri, 1 Jul 2016 04:38:34 -0400 Received: from out4433.biz.mail.alibaba.com ([47.88.44.33]:40268 "EHLO out4433.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752160AbcGAIia (ORCPT ); Fri, 1 Jul 2016 04:38:30 -0400 X-Greylist: delayed 320 seconds by postgrey-1.27 at vger.kernel.org; Fri, 01 Jul 2016 04:38:30 EDT X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R821e4;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e02c03291;MF=hillf.zj@alibaba-inc.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_----4zXE6bK_1467361823; Reply-To: "Hillf Danton" From: "Hillf Danton" To: "'Dave Hansen'" , "Dave Hansen" Cc: "Minchan Kim" , "linux-kernel" , References: <016001d1d36e$ef1db5a0$cd5920e0$@alibaba-inc.com> In-Reply-To: <016001d1d36e$ef1db5a0$cd5920e0$@alibaba-inc.com> Subject: Re: [PATCH 4/6] mm: move flush in madvise_free_pte_range() Date: Fri, 01 Jul 2016 16:30:23 +0800 Message-ID: <016101d1d372$d0317650$709462f0$@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQE9cn9jR61EemHudZJSaVsLqW/XdKEr+Omg Content-Language: zh-cn Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > From: Dave Hansen > > I think this code is OK and does not *need* to be patched. We > are just rewriting the PTE without the Accessed and Dirty bits. > The hardware could come along and set them at any time with or > without the erratum that this series addresses > > But this does make the ptep_get_and_clear_full() and > tlb_remove_tlb_entry() calls here more consistent with the other > places they are used together and look *obviously* the same > between call-sites. > > Signed-off-by: Dave Hansen > Cc: Minchan Kim > --- > > b/mm/madvise.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff -puN mm/madvise.c~knl-leak-40-madvise_free_pte_range-move-flush mm/madvise.c > --- a/mm/madvise.c~knl-leak-40-madvise_free_pte_range-move-flush 2016-06-30 17:10:42.557246755 -0700 > +++ b/mm/madvise.c 2016-06-30 17:10:42.561246936 -0700 > @@ -369,13 +369,13 @@ static int madvise_free_pte_range(pmd_t > */ > ptent = ptep_get_and_clear_full(mm, addr, pte, > tlb->fullmm); > + tlb_remove_tlb_entry(tlb, pte, addr); > Then the current comment has to be updated, no?-/ thanks Hillf > ptent = pte_mkold(ptent); > ptent = pte_mkclean(ptent); > set_pte_at(mm, addr, pte, ptent); > if (PageActive(page)) > deactivate_page(page); > - tlb_remove_tlb_entry(tlb, pte, addr); > } > } > out: > _ >