From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by ozlabs.org (Postfix) with ESMTP id 4E4122C00F9 for ; Thu, 25 Apr 2013 01:15:26 +1000 (EST) Date: Wed, 24 Apr 2013 17:14:57 +0200 From: Andrea Arcangeli To: "Aneesh Kumar K.V" Subject: Re: [PATCH -V6 18/27] mm/THP: withdraw the pgtable after pmdp related operations Message-ID: <20130424151457.GA20440@redhat.com> References: <1366624861-24948-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1366624861-24948-19-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20130422154901.GC13442@redhat.com> <87a9oo2t5a.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <87a9oo2t5a.fsf@linux.vnet.ibm.com> Cc: paulus@samba.org, linuxppc-dev@lists.ozlabs.org, David Gibson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, On Wed, Apr 24, 2013 at 02:38:01PM +0530, Aneesh Kumar K.V wrote: > From 7444a5eda33c00eea465b51c405cb830c57513b7 Mon Sep 17 00:00:00 2001 > From: "Aneesh Kumar K.V" > Date: Wed, 6 Mar 2013 12:50:37 +0530 > Subject: [PATCH] mm/THP: withdraw the pgtable after pmdp related operations > > For architectures like ppc64 we look at deposited pgtable when > calling pmdp_get_and_clear. So do the pgtable_trans_huge_withdraw > after finishing pmdp related operations. > > Cc: Andrea Arcangeli > Signed-off-by: Aneesh Kumar K.V > --- > mm/huge_memory.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) Reviewed-by: Andrea Arcangeli > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 84f3180..21c5ebd 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1363,9 +1363,15 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, > struct page *page; > pgtable_t pgtable; > pmd_t orig_pmd; > - pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd); > + /* > + * For architectures like ppc64 we look at deposited pgtable > + * when calling pmdp_get_and_clear. So do the > + * pgtable_trans_huge_withdraw after finishing pmdp related > + * operations. > + */ > orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd); > tlb_remove_pmd_tlb_entry(tlb, pmd, addr); > + pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd); So I assume you're going to check the pmdp pointer address in _withdraw, as the *pmd content is already clear. And that you're checking the deposited pmd earlier in pmdp_get_and_clear. A bit strange overall not seeing how exactly you're using the new parameter and the deposited pmds, but safe. Thanks, Andrea