From patchwork Tue May 19 10:03:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibo Mao X-Patchwork-Id: 11557397 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 77F1614C0 for ; Tue, 19 May 2020 10:04:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A145207E8 for ; Tue, 19 May 2020 10:04:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728612AbgESKEH (ORCPT ); Tue, 19 May 2020 06:04:07 -0400 Received: from mail.loongson.cn ([114.242.206.163]:42526 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728286AbgESKEE (ORCPT ); Tue, 19 May 2020 06:04:04 -0400 Received: from kvm-dev1.localdomain (unknown [10.2.5.134]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxz97yrsNeDoM2AA--.42S2; Tue, 19 May 2020 18:03:31 +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 v4 1/4] MIPS: Do not flush tlb page when updating PTE entry Date: Tue, 19 May 2020 18:03:27 +0800 Message-Id: <1589882610-7291-1-git-send-email-maobibo@loongson.cn> X-Mailer: git-send-email 1.8.3.1 X-CM-TRANSID: AQAAf9Dxz97yrsNeDoM2AA--.42S2 X-Coremail-Antispam: 1UD129KBjvJXoW7uFW3ZryxtF1UJrWUGr1xZrb_yoW8JFW5pF srAryvg3ykG3y0yFy8ArnY9r43J3ykGrZ8KryDCrZ0v3ZrXF18Krs3Ka42yry8ZFWak3W8 Kr4YqF4DZa12y37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkCb7Iv0xC_KF4lb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rw A2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xII jxv20xvEc7CjxVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_Cr1j6rxdM28EF7xvwV C2z280aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC 0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr 1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY 04v7MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI 0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y 0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxV W8JVWxJwCI42IY6xAIw20EY4v20xvaj40_WFyUJVCq3wCI42IY6I8E87Iv67AKxVWUJVW8 JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxU2vPfDU UUU X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org It is not necessary to flush tlb page on all CPUs if suitable PTE entry exists already during page fault handling, just updating TLB is fine. Here redefine flush_tlb_fix_spurious_fault as empty on MIPS system. V4: - add pte_sw_mkyoung function to implement readable privilege, and this function is only in effect on MIPS system. - add page valid bit judgement in function pte_modify V3: - add detailed changelog, modify typo issue in patch V2 v2: - split flush_tlb_fix_spurious_fault and tlb update into two patches - comments typo modification - separate tlb update and add pte readable privilege into two patches Signed-off-by: Bibo Mao --- arch/mips/include/asm/pgtable.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h index 9b01d2d..0d625c2 100644 --- a/arch/mips/include/asm/pgtable.h +++ b/arch/mips/include/asm/pgtable.h @@ -478,6 +478,8 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot) return __pgprot(prot); } +#define flush_tlb_fix_spurious_fault(vma, address) do { } while (0) + /* * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. From patchwork Tue May 19 10:03:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibo Mao X-Patchwork-Id: 11557399 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 A4E7F14C0 for ; Tue, 19 May 2020 10:04:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 906F320829 for ; Tue, 19 May 2020 10:04:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728483AbgESKED (ORCPT ); Tue, 19 May 2020 06:04:03 -0400 Received: from mail.loongson.cn ([114.242.206.163]:42500 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726121AbgESKED (ORCPT ); Tue, 19 May 2020 06:04:03 -0400 Received: from kvm-dev1.localdomain (unknown [10.2.5.134]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxz97yrsNeDoM2AA--.42S3; Tue, 19 May 2020 18:03:31 +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 v4 2/4] mm/memory.c: Update local TLB if PTE entry exists Date: Tue, 19 May 2020 18:03:28 +0800 Message-Id: <1589882610-7291-2-git-send-email-maobibo@loongson.cn> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1589882610-7291-1-git-send-email-maobibo@loongson.cn> References: <1589882610-7291-1-git-send-email-maobibo@loongson.cn> X-CM-TRANSID: AQAAf9Dxz97yrsNeDoM2AA--.42S3 X-Coremail-Antispam: 1UD129KBjvJXoWxuFW5Cr43Cr1rWr4ruF1rWFg_yoWxGw43pr yfCa1DXF4xXr18Zr4xXw4qvF15Za4rJa4kJry3Kw1Fv39xXr4fuay5G3yFvFZ5Gr95Xwsr Jr4jgF4UZay7uw7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBlb7Iv0xC_Kw4lb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI 8067AKxVWUGwA2048vs2IY020Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK0II2c7xJM28CjxkF 64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcV CY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_Cr1j6rxdM28EF7xvwVC2z280 aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzV Aqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S 6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7Mx AIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_ Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y0x0EwI xGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWx JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcV C2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU5tgA7UUUUU== X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org If two threads concurrently fault at the same address, the thread that won the race updates the PTE and its local TLB. For now, the other thread gives up, simply does nothing, and continues. It could happen that this second thread triggers another fault, whereby it only updates its local TLB while handling the fault. Instead of triggering another fault, let's directly update the local TLB of the second thread. It is only useful to architectures where software can update TLB, it may bring out some negative effect if update_mmu_cache is used for other purpose also. It seldom happens where multiple threads access the same page at the same time, so the negative effect is limited on other arches. Signed-off-by: Bibo Mao --- mm/memory.c | 44 +++++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 17 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index f703fe8..2eb59a9 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1770,8 +1770,8 @@ static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr, } entry = pte_mkyoung(*pte); entry = maybe_mkwrite(pte_mkdirty(entry), vma); - if (ptep_set_access_flags(vma, addr, pte, entry, 1)) - update_mmu_cache(vma, addr, pte); + ptep_set_access_flags(vma, addr, pte, entry, 1); + update_mmu_cache(vma, addr, pte); } goto out_unlock; } @@ -2436,17 +2436,16 @@ static inline bool cow_user_page(struct page *dst, struct page *src, if (!likely(pte_same(*vmf->pte, vmf->orig_pte))) { /* * Other thread has already handled the fault - * and we don't need to do anything. If it's - * not the case, the fault will be triggered - * again on the same address. + * and update local tlb only */ + update_mmu_cache(vma, addr, vmf->pte); ret = false; goto pte_unlock; } entry = pte_mkyoung(vmf->orig_pte); - if (ptep_set_access_flags(vma, addr, vmf->pte, entry, 0)) - update_mmu_cache(vma, addr, vmf->pte); + ptep_set_access_flags(vma, addr, vmf->pte, entry, 0); + update_mmu_cache(vma, addr, vmf->pte); } /* @@ -2463,7 +2462,8 @@ static inline bool cow_user_page(struct page *dst, struct page *src, vmf->pte = pte_offset_map_lock(mm, vmf->pmd, addr, &vmf->ptl); locked = true; if (!likely(pte_same(*vmf->pte, vmf->orig_pte))) { - /* The PTE changed under us. Retry page fault. */ + /* The PTE changed under us, update local tlb */ + update_mmu_cache(vma, addr, vmf->pte); ret = false; goto pte_unlock; } @@ -2618,8 +2618,8 @@ static inline void wp_page_reuse(struct vm_fault *vmf) flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); entry = pte_mkyoung(vmf->orig_pte); entry = maybe_mkwrite(pte_mkdirty(entry), vma); - if (ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1)) - update_mmu_cache(vma, vmf->address, vmf->pte); + ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1); + update_mmu_cache(vma, vmf->address, vmf->pte); pte_unmap_unlock(vmf->pte, vmf->ptl); } @@ -2752,6 +2752,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) new_page = old_page; page_copied = 1; } else { + update_mmu_cache(vma, vmf->address, vmf->pte); mem_cgroup_cancel_charge(new_page, memcg, false); } @@ -2812,6 +2813,7 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf) * pte_offset_map_lock. */ if (!pte_same(*vmf->pte, vmf->orig_pte)) { + update_mmu_cache(vmf->vma, vmf->address, vmf->pte); pte_unmap_unlock(vmf->pte, vmf->ptl); return VM_FAULT_NOPAGE; } @@ -2936,6 +2938,7 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); if (!pte_same(*vmf->pte, vmf->orig_pte)) { + update_mmu_cache(vma, vmf->address, vmf->pte); unlock_page(vmf->page); pte_unmap_unlock(vmf->pte, vmf->ptl); put_page(vmf->page); @@ -3341,8 +3344,10 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) vma->vm_page_prot)); vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); - if (!pte_none(*vmf->pte)) + if (!pte_none(*vmf->pte)) { + update_mmu_cache(vma, vmf->address, vmf->pte); goto unlock; + } ret = check_stable_address_space(vma->vm_mm); if (ret) goto unlock; @@ -3378,8 +3383,10 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); - if (!pte_none(*vmf->pte)) + if (!pte_none(*vmf->pte)) { + update_mmu_cache(vma, vmf->address, vmf->pte); goto release; + } ret = check_stable_address_space(vma->vm_mm); if (ret) @@ -3646,8 +3653,10 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg, } /* Re-check under ptl */ - if (unlikely(!pte_none(*vmf->pte))) + if (unlikely(!pte_none(*vmf->pte))) { + update_mmu_cache(vma, vmf->address, vmf->pte); return VM_FAULT_NOPAGE; + } flush_icache_page(vma, page); entry = mk_pte(page, vma->vm_page_prot); @@ -4224,18 +4233,18 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); spin_lock(vmf->ptl); entry = vmf->orig_pte; - if (unlikely(!pte_same(*vmf->pte, entry))) + if (unlikely(!pte_same(*vmf->pte, entry))) { + update_mmu_cache(vmf->vma, vmf->address, vmf->pte); goto unlock; + } if (vmf->flags & FAULT_FLAG_WRITE) { if (!pte_write(entry)) return do_wp_page(vmf); entry = pte_mkdirty(entry); } entry = pte_mkyoung(entry); - if (ptep_set_access_flags(vmf->vma, vmf->address, vmf->pte, entry, + if (!ptep_set_access_flags(vmf->vma, vmf->address, vmf->pte, entry, vmf->flags & FAULT_FLAG_WRITE)) { - update_mmu_cache(vmf->vma, vmf->address, vmf->pte); - } else { /* * This is needed only for protection faults but the arch code * is not yet telling us if this is a protection fault or not. @@ -4245,6 +4254,7 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) if (vmf->flags & FAULT_FLAG_WRITE) flush_tlb_fix_spurious_fault(vmf->vma, vmf->address); } + update_mmu_cache(vmf->vma, vmf->address, vmf->pte); unlock: pte_unmap_unlock(vmf->pte, vmf->ptl); return 0; From patchwork Tue May 19 10:03:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibo Mao X-Patchwork-Id: 11557393 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 D2D6314C0 for ; Tue, 19 May 2020 10:04:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C50BE206D4 for ; Tue, 19 May 2020 10:04:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726938AbgESKEC (ORCPT ); Tue, 19 May 2020 06:04:02 -0400 Received: from mail.loongson.cn ([114.242.206.163]:42506 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726508AbgESKEC (ORCPT ); Tue, 19 May 2020 06:04:02 -0400 Received: from kvm-dev1.localdomain (unknown [10.2.5.134]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxz97yrsNeDoM2AA--.42S4; Tue, 19 May 2020 18:03:32 +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 v4 3/4] mm/memory.c: Add memory read privilege on page fault handling Date: Tue, 19 May 2020 18:03:29 +0800 Message-Id: <1589882610-7291-3-git-send-email-maobibo@loongson.cn> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1589882610-7291-1-git-send-email-maobibo@loongson.cn> References: <1589882610-7291-1-git-send-email-maobibo@loongson.cn> X-CM-TRANSID: AQAAf9Dxz97yrsNeDoM2AA--.42S4 X-Coremail-Antispam: 1UD129KBjvJXoWxZFy5KF13KFyfJrykZry8uFg_yoW5AryfpF Z7Cw1F9rsxXw18AFWfGFn2kr15ua1rKFWrurySkw1ku3ZxJrs8Wrs7GayFv34kJFWkK3Wr Gr4jqr4UZayIvaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBGb7Iv0xC_Kw4lb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI 8067AKxVWUXwA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF 64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcV CY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_Cr1j6rxdM28EF7xvwVC2z280 aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzV Aqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S 6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7Mx AIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_ Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y0x0EwI xGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWxJVW8 Jr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0x vEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07b5wZcUUUUU= X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Here add pte_sw_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. It is noop function on other arches, there is no negative influence on those architectures. Signed-off-by: Bibo Mao --- arch/mips/include/asm/pgtable.h | 2 ++ include/asm-generic/pgtable.h | 15 +++++++++++++++ mm/memory.c | 3 +++ 3 files changed, 20 insertions(+) diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h index 0d625c2..755d534 100644 --- a/arch/mips/include/asm/pgtable.h +++ b/arch/mips/include/asm/pgtable.h @@ -414,6 +414,8 @@ static inline pte_t pte_mkyoung(pte_t pte) return pte; } +#define pte_sw_mkyoung pte_mkyoung + #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE; } diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 329b8c8..2542ef1 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -227,6 +227,21 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres } #endif +/* + * On some architectures hardware does not set page access bit when accessing + * memory page, it is responsibilty of software setting this bit. It brings + * out extra page fault penalty to track page access bit. For optimization page + * access bit can be set during all page fault flow on these arches. + * To be differentiate with macro pte_mkyoung, this macro is used on platforms + * where software maintains page access bit. + */ +#ifndef pte_sw_mkyoung +static inline pte_t pte_sw_mkyoung(pte_t pte) +{ + return pte; +} +#endif + #ifndef pte_savedwrite #define pte_savedwrite pte_write #endif diff --git a/mm/memory.c b/mm/memory.c index 2eb59a9..d9700b1 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_sw_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_sw_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_sw_mkyoung(entry); if (write) entry = maybe_mkwrite(pte_mkdirty(entry), vma); /* copy-on-write page */ From patchwork Tue May 19 10:03:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibo Mao X-Patchwork-Id: 11557401 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 BF76A60D for ; Tue, 19 May 2020 10:04:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEA76206BE for ; Tue, 19 May 2020 10:04:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728183AbgESKEC (ORCPT ); Tue, 19 May 2020 06:04:02 -0400 Received: from mail.loongson.cn ([114.242.206.163]:42508 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726595AbgESKEC (ORCPT ); Tue, 19 May 2020 06:04:02 -0400 Received: from kvm-dev1.localdomain (unknown [10.2.5.134]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxz97yrsNeDoM2AA--.42S5; Tue, 19 May 2020 18:03:32 +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 v4 4/4] MIPS: mm: add page valid judgement in function pte_modify Date: Tue, 19 May 2020 18:03:30 +0800 Message-Id: <1589882610-7291-4-git-send-email-maobibo@loongson.cn> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1589882610-7291-1-git-send-email-maobibo@loongson.cn> References: <1589882610-7291-1-git-send-email-maobibo@loongson.cn> X-CM-TRANSID: AQAAf9Dxz97yrsNeDoM2AA--.42S5 X-Coremail-Antispam: 1UD129KBjvdXoWrtFW8AryxtFWfuw43ur4DJwb_yoWDWwbEka 17Zw4fCr95JF17uFW7A3WrJry7Ka48u3Wqyas7J3WavFn0gr45Cay8WryUArZ8uFsFyr40 qa95G343CFsxKjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb68YjsxI4VW3JwAYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7 IE14v26r1rM28IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC64kIII0Yj41l84x0c7CE w4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6x kF7I0E14v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I8E87Iv 6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c 02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE 4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42 xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWU GwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI4 8JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4U JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcV C2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU8SfO7UUUUU== X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org If original PTE has _PAGE_ACCESSED bit set, and new pte has no _PAGE_NO_READ bit set, we can add _PAGE_SILENT_READ bit to enable page valid bit. Signed-off-by: Bibo Mao --- arch/mips/include/asm/pgtable.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h index 755d534..4f6eb56 100644 --- a/arch/mips/include/asm/pgtable.h +++ b/arch/mips/include/asm/pgtable.h @@ -509,8 +509,11 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) #else static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { - return __pte((pte_val(pte) & _PAGE_CHG_MASK) | - (pgprot_val(newprot) & ~_PAGE_CHG_MASK)); + pte_val(pte) &= _PAGE_CHG_MASK; + pte_val(pte) |= pgprot_val(newprot) & ~_PAGE_CHG_MASK; + if ((pte_val(pte) & _PAGE_ACCESSED) && !(pte_val(pte) & _PAGE_NO_READ)) + pte_val(pte) |= _PAGE_SILENT_READ; + return pte; } #endif