From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) by kanga.kvack.org (Postfix) with ESMTP id 447176B006E for ; Fri, 8 May 2015 18:24:31 -0400 (EDT) Received: by pabtp1 with SMTP id tp1so60469251pab.2 for ; Fri, 08 May 2015 15:24:31 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id fx4si8695339pbb.205.2015.05.08.15.24.29 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 08 May 2015 15:24:29 -0700 (PDT) Date: Fri, 8 May 2015 15:24:28 -0700 From: Andrew Morton Subject: Re: [PATCH V2 1/2] mm/thp: Split out pmd collpase flush into a seperate functions Message-Id: <20150508152428.4326eaaae99b74fa53c96f23@linux-foundation.org> In-Reply-To: <1430983408-24924-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1430983408-24924-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: mpe@ellerman.id.au, paulus@samba.org, benh@kernel.crashing.org, kirill.shutemov@linux.intel.com, aarcange@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org On Thu, 7 May 2015 12:53:27 +0530 "Aneesh Kumar K.V" wrote: > After this patch pmdp_* functions operate only on hugepage pte, > and not on regular pmd_t values pointing to page table. > The patch looks like a pretty safe no-op for non-powerpc? > --- a/arch/powerpc/include/asm/pgtable-ppc64.h > +++ b/arch/powerpc/include/asm/pgtable-ppc64.h > @@ -576,6 +576,10 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr, > extern void pmdp_splitting_flush(struct vm_area_struct *vma, > unsigned long address, pmd_t *pmdp); > > +#define __HAVE_ARCH_PMDP_COLLAPSE_FLUSH > +extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, > + unsigned long address, pmd_t *pmdp); > + The fashionable way of doing this is extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp); #define pmdp_collapse_flush pmdp_collapse_flush then, elsewhere, #ifndef pmdp_collapse_flush static inline pmd_t pmdp_collapse_flush(...) {} #define pmdp_collapse_flush pmdp_collapse_flush #endif It avoids introducing a second (ugly) symbol into the kernel. -- 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