From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDB00C433E0 for ; Thu, 23 Jul 2020 05:06:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A591520714 for ; Thu, 23 Jul 2020 05:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726068AbgGWFGq (ORCPT ); Thu, 23 Jul 2020 01:06:46 -0400 Received: from foss.arm.com ([217.140.110.172]:39054 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725773AbgGWFGq (ORCPT ); Thu, 23 Jul 2020 01:06:46 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4256931B; Wed, 22 Jul 2020 22:06:45 -0700 (PDT) Received: from [10.163.85.73] (unknown [10.163.85.73]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EB1A13F718; Wed, 22 Jul 2020 22:06:42 -0700 (PDT) Subject: Re: [PATCH v2 2/4] mm/hugetlb.c: Remove the unnecessary non_swap_entry() To: Baoquan He , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, mike.kravetz@oracle.com, david@redhat.com, akpm@linux-foundation.org References: <20200723032248.24772-1-bhe@redhat.com> <20200723032248.24772-3-bhe@redhat.com> From: Anshuman Khandual Message-ID: Date: Thu, 23 Jul 2020 10:36:14 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200723032248.24772-3-bhe@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/23/2020 08:52 AM, Baoquan He wrote: > The checking is_migration_entry() and is_hwpoison_entry() are stricter > than non_swap_entry(), means they have covered the conditional check > which non_swap_entry() is doing. They are no stricter as such but implicitly contains non_swap_entry() in itself. If a swap entry tests positive for either is_[migration|hwpoison]_entry(), then its swap_type() is among SWP_MIGRATION_READ, SWP_MIGRATION_WRITE and SWP_HWPOISON. All these types >= MAX_SWAPFILES, exactly what is asserted with non_swap_entry(). > > Hence remove the unnecessary non_swap_entry() in is_hugetlb_entry_migration() > and is_hugetlb_entry_hwpoisoned() to simplify code. > > Signed-off-by: Baoquan He > Reviewed-by: Mike Kravetz > Reviewed-by: David Hildenbrand > --- > mm/hugetlb.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 3569e731e66b..c14837854392 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -3748,7 +3748,7 @@ bool is_hugetlb_entry_migration(pte_t pte) > if (huge_pte_none(pte) || pte_present(pte)) > return false; > swp = pte_to_swp_entry(pte); > - if (non_swap_entry(swp) && is_migration_entry(swp)) > + if (is_migration_entry(swp)) > return true; > else > return false; > @@ -3761,7 +3761,7 @@ static bool is_hugetlb_entry_hwpoisoned(pte_t pte) > if (huge_pte_none(pte) || pte_present(pte)) > return false; > swp = pte_to_swp_entry(pte); > - if (non_swap_entry(swp) && is_hwpoison_entry(swp)) > + if (is_hwpoison_entry(swp)) > return true; > else > return false; > It would be better if the commit message contains details about the existing redundant check. But either way. Reviewed-by: Anshuman Khandual