From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [PATCHv4 31/39] thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page() Date: Tue, 21 May 2013 16:38:27 -0700 Message-ID: <519C0573.4030808@sr71.net> References: <1368321816-17719-1-git-send-email-kirill.shutemov@linux.intel.com> <1368321816-17719-32-git-send-email-kirill.shutemov@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Andrea Arcangeli , Andrew Morton , Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: "Kirill A. Shutemov" Return-path: In-Reply-To: <1368321816-17719-32-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On 05/11/2013 06:23 PM, Kirill A. Shutemov wrote: > From: "Kirill A. Shutemov" > > do_huge_pmd_anonymous_page() has copy-pasted piece of handle_mm_fault() > to handle fallback path. > > Let's consolidate code back by introducing VM_FAULT_FALLBACK return > code. > > Signed-off-by: Kirill A. Shutemov > --- > include/linux/huge_mm.h | 3 --- > include/linux/mm.h | 3 ++- > mm/huge_memory.c | 31 +++++-------------------------- > mm/memory.c | 9 ++++++--- > 4 files changed, 13 insertions(+), 33 deletions Wow, nice diffstat! This and the previous patch can go in the cleanups pile, no? > @@ -3788,9 +3788,12 @@ retry: > if (!pmd) > return VM_FAULT_OOM; > if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) { > + int ret = 0; > if (!vma->vm_ops) > - return do_huge_pmd_anonymous_page(mm, vma, address, > - pmd, flags); > + ret = do_huge_pmd_anonymous_page(mm, vma, address, > + pmd, flags); > + if ((ret & VM_FAULT_FALLBACK) == 0) > + return ret; This could use a small comment about where the code flow is going, when and why. FWIW, I vastly prefer the '!' form in these: if (!(ret & VM_FAULT_FALLBACK)) -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754404Ab3EUXie (ORCPT ); Tue, 21 May 2013 19:38:34 -0400 Received: from www.sr71.net ([198.145.64.142]:46382 "EHLO blackbird.sr71.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754244Ab3EUXia (ORCPT ); Tue, 21 May 2013 19:38:30 -0400 Message-ID: <519C0573.4030808@sr71.net> Date: Tue, 21 May 2013 16:38:27 -0700 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: "Kirill A. Shutemov" CC: Andrea Arcangeli , Andrew Morton , Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv4 31/39] thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page() References: <1368321816-17719-1-git-send-email-kirill.shutemov@linux.intel.com> <1368321816-17719-32-git-send-email-kirill.shutemov@linux.intel.com> In-Reply-To: <1368321816-17719-32-git-send-email-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/11/2013 06:23 PM, Kirill A. Shutemov wrote: > From: "Kirill A. Shutemov" > > do_huge_pmd_anonymous_page() has copy-pasted piece of handle_mm_fault() > to handle fallback path. > > Let's consolidate code back by introducing VM_FAULT_FALLBACK return > code. > > Signed-off-by: Kirill A. Shutemov > --- > include/linux/huge_mm.h | 3 --- > include/linux/mm.h | 3 ++- > mm/huge_memory.c | 31 +++++-------------------------- > mm/memory.c | 9 ++++++--- > 4 files changed, 13 insertions(+), 33 deletions Wow, nice diffstat! This and the previous patch can go in the cleanups pile, no? > @@ -3788,9 +3788,12 @@ retry: > if (!pmd) > return VM_FAULT_OOM; > if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) { > + int ret = 0; > if (!vma->vm_ops) > - return do_huge_pmd_anonymous_page(mm, vma, address, > - pmd, flags); > + ret = do_huge_pmd_anonymous_page(mm, vma, address, > + pmd, flags); > + if ((ret & VM_FAULT_FALLBACK) == 0) > + return ret; This could use a small comment about where the code flow is going, when and why. FWIW, I vastly prefer the '!' form in these: if (!(ret & VM_FAULT_FALLBACK))