From patchwork Mon Jul 13 15:02:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 6780181 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E5E89C05AC for ; Mon, 13 Jul 2015 15:03:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 18EB32047C for ; Mon, 13 Jul 2015 15:03:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 329F120502 for ; Mon, 13 Jul 2015 15:03:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752216AbbGMPCl (ORCPT ); Mon, 13 Jul 2015 11:02:41 -0400 Received: from mga02.intel.com ([134.134.136.20]:7210 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751760AbbGMPCh (ORCPT ); Mon, 13 Jul 2015 11:02:37 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 13 Jul 2015 08:02:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,463,1432623600"; d="scan'208";a="763511707" Received: from bguvendi-mobl.amr.corp.intel.com (HELO thog.int.wil.cx) ([10.252.135.174]) by orsmga002.jf.intel.com with SMTP; 13 Jul 2015 08:02:36 -0700 Received: by thog.int.wil.cx (Postfix, from userid 1000) id 6A14A5FBAB; Mon, 13 Jul 2015 11:02:35 -0400 (EDT) Date: Mon, 13 Jul 2015 11:02:35 -0400 From: Matthew Wilcox To: Jeff Moyer Cc: Matthew Wilcox , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 06/10] mm: Add vmf_insert_pfn_pmd() Message-ID: <20150713150235.GG13681@linux.intel.com> References: <1436560165-8943-1-git-send-email-matthew.r.wilcox@intel.com> <1436560165-8943-7-git-send-email-matthew.r.wilcox@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-8.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Mon, Jul 13, 2015 at 09:23:41AM -0400, Jeff Moyer wrote: > Matthew Wilcox writes: > > > +static int insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > > + pmd_t *pmd, unsigned long pfn, pgprot_t prot, bool write) > > +{ > > + return VM_FAULT_NOPAGE; > > +} > > What's the point of the return value? Good point. Originally, it paralleled insert_pfn() in mm/memory.c, but it became apparent that the return code of 0 or -Exxx was useless, and in converting insert_pfn_pmd over to VM_FAULT_ codes, all possible return codes were going to be VM_FAULT_NOPAGE. It didn't occur to me to take it one step further and make the function return void. It doesn't make much difference either way: I suppose it's slightly cleaner. I'll integrate this for the next release. --- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 26d0fc1..5ffdcaa 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -837,7 +837,7 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, return 0; } -static int insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, +static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, unsigned long pfn, pgprot_t prot, bool write) { struct mm_struct *mm = vma->vm_mm; @@ -855,7 +855,6 @@ static int insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, update_mmu_cache_pmd(vma, addr, pmd); } spin_unlock(ptl); - return VM_FAULT_NOPAGE; } int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, @@ -877,7 +876,8 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, return VM_FAULT_SIGBUS; if (track_pfn_insert(vma, &pgprot, pfn)) return VM_FAULT_SIGBUS; - return insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write); + insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write); + return VM_FAULT_NOPAGE; } int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,