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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 75605C5B57D for ; Fri, 5 Jul 2019 06:13:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5812C2082E for ; Fri, 5 Jul 2019 06:13:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727972AbfGEGNA (ORCPT ); Fri, 5 Jul 2019 02:13:00 -0400 Received: from foss.arm.com ([217.140.110.172]:58598 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727753AbfGEGM7 (ORCPT ); Fri, 5 Jul 2019 02:12:59 -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 AE148360; Thu, 4 Jul 2019 23:12:58 -0700 (PDT) Received: from p8cg001049571a15.blr.arm.com (p8cg001049571a15.blr.arm.com [10.162.41.127]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7B6353F246; Thu, 4 Jul 2019 23:14:50 -0700 (PDT) From: Anshuman Khandual To: linux-mm@kvack.org Cc: Anshuman Khandual , Oscar Salvador , Michal Hocko , Qian Cai , Andrew Morton , linux-kernel@vger.kernel.org Subject: [PATCH] mm/isolate: Drop pre-validating migrate type in undo_isolate_page_range() Date: Fri, 5 Jul 2019 11:42:41 +0530 Message-Id: <1562307161-30554-1-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org unset_migratetype_isolate() already validates under zone lock that a given page has already been isolated as MIGRATE_ISOLATE. There is no need for another check before. Hence just drop this redundant validation. Cc: Oscar Salvador Cc: Michal Hocko Cc: Qian Cai Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- Is there any particular reason to do this migratetype pre-check without zone lock before calling unsert_migrate_isolate() ? If not this should be removed. mm/page_isolation.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/page_isolation.c b/mm/page_isolation.c index e3638a5bafff..f529d250c8a5 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -243,7 +243,7 @@ int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, pfn < end_pfn; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); - if (!page || !is_migrate_isolate_page(page)) + if (!page) continue; unset_migratetype_isolate(page, migratetype); } -- 2.20.1