From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH 1/2] MIPS: set page access bit with pgprot on some MIPS platform Date: Fri, 5 Jun 2020 18:08:03 -0700 Message-ID: <20200605180803.9ba58249ed681f4da9822f43@linux-foundation.org> References: <1591348266-28392-1-git-send-email-maobibo@loongson.cn> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1591348266-28392-1-git-send-email-maobibo@loongson.cn> Sender: linux-mips-owner@vger.kernel.org To: Bibo Mao Cc: Thomas Bogendoerfer , Paul Burton , Jiaxun Yang , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org List-Id: linux-arch.vger.kernel.org On Fri, 5 Jun 2020 17:11:05 +0800 Bibo Mao wrote: > On MIPS system which has rixi hardware bit, page access bit is not > set in pgrot. For memory reading, there will be one page fault to > allocate physical page; however valid bit is not set, there will > be the second fast tlb-miss fault handling to set valid/access bit. > > This patch set page access/valid bit with pgrot if there is reading > access privilege. It will reduce one tlb-miss handling for memory > reading access. > > The valid/access bit will be cleared in order to track memory > accessing activity. If the page is accessed, tlb-miss fast handling > will set valid/access bit, pte_sw_mkyoung is not necessary in slow > page fault path. This patch removes pte_sw_mkyoung function which > is defined as empty function except MIPS system. > > ... > > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2704,7 +2704,6 @@ 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 > @@ -3379,7 +3378,6 @@ 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)); > > @@ -3662,7 +3660,6 @@ 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 */ Only affects mips, so cheerily Acked-by: Andrew Morton From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:58894 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726803AbgFFBIG (ORCPT ); Fri, 5 Jun 2020 21:08:06 -0400 Date: Fri, 5 Jun 2020 18:08:03 -0700 From: Andrew Morton Subject: Re: [PATCH 1/2] MIPS: set page access bit with pgprot on some MIPS platform Message-ID: <20200605180803.9ba58249ed681f4da9822f43@linux-foundation.org> In-Reply-To: <1591348266-28392-1-git-send-email-maobibo@loongson.cn> References: <1591348266-28392-1-git-send-email-maobibo@loongson.cn> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Bibo Mao Cc: Thomas Bogendoerfer , Paul Burton , Jiaxun Yang , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org Message-ID: <20200606010803.AzIpA_FnymIdSbbWURDNNdZv7sMmX_TE_U-45NvBIyo@z> On Fri, 5 Jun 2020 17:11:05 +0800 Bibo Mao wrote: > On MIPS system which has rixi hardware bit, page access bit is not > set in pgrot. For memory reading, there will be one page fault to > allocate physical page; however valid bit is not set, there will > be the second fast tlb-miss fault handling to set valid/access bit. > > This patch set page access/valid bit with pgrot if there is reading > access privilege. It will reduce one tlb-miss handling for memory > reading access. > > The valid/access bit will be cleared in order to track memory > accessing activity. If the page is accessed, tlb-miss fast handling > will set valid/access bit, pte_sw_mkyoung is not necessary in slow > page fault path. This patch removes pte_sw_mkyoung function which > is defined as empty function except MIPS system. > > ... > > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2704,7 +2704,6 @@ 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 > @@ -3379,7 +3378,6 @@ 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)); > > @@ -3662,7 +3660,6 @@ 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 */ Only affects mips, so cheerily Acked-by: Andrew Morton