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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 9F97DC2BA1A for ; Tue, 7 Apr 2020 03:04:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 620D2208FE for ; Tue, 7 Apr 2020 03:04:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="cWbsnPsN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 620D2208FE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 156468E0005; Mon, 6 Apr 2020 23:04:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 107238E0001; Mon, 6 Apr 2020 23:04:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F36E28E0005; Mon, 6 Apr 2020 23:04:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0172.hostedemail.com [216.40.44.172]) by kanga.kvack.org (Postfix) with ESMTP id DA7D88E0001 for ; Mon, 6 Apr 2020 23:04:01 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 9796EA8C0 for ; Tue, 7 Apr 2020 03:04:01 +0000 (UTC) X-FDA: 76679564682.02.leg74_5d53c3d441e2f X-HE-Tag: leg74_5d53c3d441e2f X-Filterd-Recvd-Size: 3427 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:04:01 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2932421473; Tue, 7 Apr 2020 03:04:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586228640; bh=9Duap7x4fqhOZWrLjM7un6wlPUfYoZorQh/buerEPtk=; h=Date:From:To:Subject:In-Reply-To:From; b=cWbsnPsNgS+/FEjillqMf/CXWBch7peaTf86tTpl11Zjf3tMV+QRVbI6mkeuRmaru QZbB//u6PytvnpVT1bOKMcyo0sjI/yhvDf76OlEobGM45TaYHCxHLqfFni4ZGOtAGm hYfdrvuUS26CKLnjiKfGvzGNvL88AXd1sU2Zo0Bo= Date: Mon, 06 Apr 2020 20:03:59 -0700 From: Andrew Morton To: akpm@linux-foundation.org, anshuman.khandual@arm.com, geert@linux-m68k.org, guoren@kernel.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, paulburton@kernel.org, ralf@linux-mips.org, rppt@linux.ibm.com, torvalds@linux-foundation.org Subject: [patch 009/166] mm/vma: append unlikely() while testing VMA access permissions Message-ID: <20200407030359.fjEzaTEK_%akpm@linux-foundation.org> In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Anshuman Khandual Subject: mm/vma: append unlikely() while testing VMA access permissions It is unlikely that an inaccessible VMA without required permission flags will get a page fault. Hence lets just append unlikely() directive to such checks in order to improve performance while also standardizing it across various platforms. Link: http://lkml.kernel.org/r/1582525304-32113-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Reviewed-by: Andrew Morton Cc: Guo Ren Cc: Geert Uytterhoeven Cc: Ralf Baechle Cc: Paul Burton Cc: Mike Rapoport Signed-off-by: Andrew Morton --- arch/csky/mm/fault.c | 2 +- arch/m68k/mm/fault.c | 2 +- arch/mips/mm/fault.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) --- a/arch/csky/mm/fault.c~mm-vma-append-unlikely-while-testing-vma-access-permissions +++ a/arch/csky/mm/fault.c @@ -141,7 +141,7 @@ good_area: if (!(vma->vm_flags & VM_WRITE)) goto bad_area; } else { - if (!vma_is_accessible(vma)) + if (unlikely(!vma_is_accessible(vma))) goto bad_area; } --- a/arch/m68k/mm/fault.c~mm-vma-append-unlikely-while-testing-vma-access-permissions +++ a/arch/m68k/mm/fault.c @@ -125,7 +125,7 @@ good_area: case 1: /* read, present */ goto acc_err; case 0: /* read, not present */ - if (!vma_is_accessible(vma)) + if (unlikely(!vma_is_accessible(vma))) goto acc_err; } --- a/arch/mips/mm/fault.c~mm-vma-append-unlikely-while-testing-vma-access-permissions +++ a/arch/mips/mm/fault.c @@ -142,7 +142,7 @@ good_area: goto bad_area; } } else { - if (!vma_is_accessible(vma)) + if (unlikely(!vma_is_accessible(vma))) goto bad_area; } } _