From patchwork Mon May 18 05:08:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibo Mao X-Patchwork-Id: 11554699 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 977C690 for ; Mon, 18 May 2020 05:09:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89E362084C for ; Mon, 18 May 2020 05:09:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726355AbgERFJs (ORCPT ); Mon, 18 May 2020 01:09:48 -0400 Received: from mail.loongson.cn ([114.242.206.163]:58152 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726358AbgERFJr (ORCPT ); Mon, 18 May 2020 01:09:47 -0400 Received: from kvm-dev1.localdomain (unknown [10.2.5.134]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxb99lGMJeaPY1AA--.27S4; Mon, 18 May 2020 13:08:54 +0800 (CST) From: Bibo Mao To: Thomas Bogendoerfer , Jiaxun Yang , Huacai Chen , Andrew Morton , Paul Burton , Dmitry Korotin , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Stafford Horne , Steven Price , Anshuman Khandual Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Mike Rapoport , Sergei Shtylyov , "Maciej W. Rozycki" , linux-mm@kvack.org, David Hildenbrand Subject: [PATCH v3 3/3] mm/memory.c: Add memory read privilege before filling PTE entry Date: Mon, 18 May 2020 13:08:49 +0800 Message-Id: <1589778529-25627-3-git-send-email-maobibo@loongson.cn> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1589778529-25627-1-git-send-email-maobibo@loongson.cn> References: <1589778529-25627-1-git-send-email-maobibo@loongson.cn> X-CM-TRANSID: AQAAf9Dxb99lGMJeaPY1AA--.27S4 X-Coremail-Antispam: 1UD129KBjvJXoW7KFW3Ar1DAF15Jr4UWw1rWFg_yoW8ZryrpF Z3Gw1q9rs7Xw1DAF4xG3Z5Ar15ua1FgayFvr95Cw1rZwnxtrs0grWxJFWFvFykAFy8Kw1r AF4jyr4UZa18uaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPSb7Iv0xC_tr1lb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI 8067AKxVWUXwA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF 64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWUCVW8JwA2z4x0Y4vE2Ix0cI8IcV CY1x0267AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280 aVCY1x0267AKxVWxJr0_GcWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4 CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvj eVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxw CY02Avz4vE-syl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAq x4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6r W5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF 7I0E14v26F4j6r4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI 0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7I U8sID7UUUUU== X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On mips platform, hw PTE entry valid bit is set in pte_mkyoung function, it is used to set physical page with readable privilege. Here add pte_mkyoung function to make page readable on MIPS platform during page fault handling. This patch improves page fault latency about 10% on my MIPS machine with lmbench lat_pagefault case. Signed-off-by: Bibo Mao --- mm/memory.c | 3 +++ mm/mprotect.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index 2eb59a9..2399dcb 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2704,6 +2704,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) } flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); entry = mk_pte(new_page, vma->vm_page_prot); + entry = pte_mkyoung(entry); entry = maybe_mkwrite(pte_mkdirty(entry), vma); /* * Clear the pte entry and flush it first, before updating the @@ -3378,6 +3379,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) __SetPageUptodate(page); entry = mk_pte(page, vma->vm_page_prot); + entry = pte_mkyoung(entry); if (vma->vm_flags & VM_WRITE) entry = pte_mkwrite(pte_mkdirty(entry)); @@ -3660,6 +3662,7 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg, flush_icache_page(vma, page); entry = mk_pte(page, vma->vm_page_prot); + entry = pte_mkyoung(entry); if (write) entry = maybe_mkwrite(pte_mkdirty(entry), vma); /* copy-on-write page */ diff --git a/mm/mprotect.c b/mm/mprotect.c index 494192ca..673f1cd 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -131,6 +131,8 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, ptent = pte_clear_uffd_wp(ptent); } + if (vma->vm_flags & VM_READ) + ptent = pte_mkyoung(ptent); /* Avoid taking write faults for known dirty pages */ if (dirty_accountable && pte_dirty(ptent) && (pte_soft_dirty(ptent) ||