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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 DC91CC433E0 for ; Fri, 19 Jun 2020 16:07:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4C5821532 for ; Fri, 19 Jun 2020 16:07:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Gbon2Nge" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394257AbgFSQHD (ORCPT ); Fri, 19 Jun 2020 12:07:03 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:25773 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2405534AbgFSQFx (ORCPT ); Fri, 19 Jun 2020 12:05:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592582751; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oYNDwtlfjBw7SDjKSzeBn7nLzHhEdZ/Papn4VLBZIoQ=; b=Gbon2NgeJHFxisp58KQlO29Oek+1Pj3M50c4T/dg4awaeXrwle+TI0q4BvSQxd+gSTSXTj pFOjJREZmFFDp7JZYag1RPKdWkUc8LM+AD/dS0NmDubKnhQPClqXzGy7066Y4YXq4hyKCG Wose3JcplJnc5Trk+G7lVvhB1Pw5T3A= Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-503-cjcit86PMOOAkAXe43enqg-1; Fri, 19 Jun 2020 12:05:48 -0400 X-MC-Unique: cjcit86PMOOAkAXe43enqg-1 Received: by mail-qk1-f199.google.com with SMTP id o63so1036156qkc.8 for ; Fri, 19 Jun 2020 09:05:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=oYNDwtlfjBw7SDjKSzeBn7nLzHhEdZ/Papn4VLBZIoQ=; b=nLc/sNwUuhuEiKYYBJ3gntBMFuVtPpfPCVV4L2xiJqlMsuhNkzvwwKMLX+pAaOte8/ nI9mhTFVDUVcKgUI9FkcOhiE6Q1SgYHi5ZoGXOqL0tYMIgZuPqRUkgbZi2z64fDKqd6F 7Dg76aMN3UlLKJ9Cs8jOvNBXSG+d4StphZ8Gn3zXaTb+rysShnGFjcr0xdCe1Qs/sI6V sjhBAWMfl6Km8DkKfxMFu0mf4hMB0svFpDfq7xCweTQBoF/4ddI2/ApGvKCzTEheJyj2 /uPB6c+C2+86HzXPdvgzDHTszOWo92MT98ulF/a81JEW75BDuBLVw25sLYkGWBKKVVQg JJNg== X-Gm-Message-State: AOAM5336kA+3+kWtm+/KjnPSenk5zYjgQdZItM+oDkPNt8YCHyzdwbvh QdP8BNZ1C3JsmaiRoXfNqtXg+aQ3lYoPUJGM1rV4VbuNx8kmV+BtRwZ76NCdG31mE5NLy0koc5j LFeSUNgCJDMnlaRfN66J5PSAb X-Received: by 2002:aed:21c8:: with SMTP id m8mr4187958qtc.224.1592582747571; Fri, 19 Jun 2020 09:05:47 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxzQfwrOgEHeZ4fmlf+FrgeIhkxqk3pvz1Rd9/fj39BAorh/CRlZ+KkHZPVWnZcxaKSEJpm8Q== X-Received: by 2002:aed:21c8:: with SMTP id m8mr4187936qtc.224.1592582747304; Fri, 19 Jun 2020 09:05:47 -0700 (PDT) Received: from xz-x1.redhat.com ([2607:9880:19c0:32::2]) by smtp.gmail.com with ESMTPSA id g11sm6412604qkk.123.2020.06.19.09.05.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jun 2020 09:05:46 -0700 (PDT) From: Peter Xu To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Gerald Schaefer , peterx@redhat.com, Andrew Morton , Andrea Arcangeli , Will Deacon , Michael Ellerman , Linus Torvalds , Russell King , linux-arm-kernel@lists.infradead.org Subject: [PATCH 04/26] mm/arm: Use general page fault accounting Date: Fri, 19 Jun 2020 12:05:16 -0400 Message-Id: <20200619160538.8641-5-peterx@redhat.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200619160538.8641-1-peterx@redhat.com> References: <20200619160538.8641-1-peterx@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use the general page fault accounting by passing regs into handle_mm_fault(). It naturally solve the issue of multiple page fault accounting when page fault retry happened. To do this, we need to pass the pt_regs pointer into __do_page_fault(). Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries, by moving it before taking mmap_sem. CC: Russell King CC: Will Deacon CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Peter Xu --- arch/arm/mm/fault.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 0d6be0f4f27c..8530befee012 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -201,7 +201,8 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) static vm_fault_t __kprobes __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, - unsigned int flags, struct task_struct *tsk) + unsigned int flags, struct task_struct *tsk, + struct pt_regs *regs) { struct vm_area_struct *vma; vm_fault_t fault; @@ -223,7 +224,7 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, goto out; } - return handle_mm_fault(vma, addr & PAGE_MASK, flags, NULL); + return handle_mm_fault(vma, addr & PAGE_MASK, flags, regs); check_stack: /* Don't allow expansion below FIRST_USER_ADDRESS */ @@ -265,6 +266,8 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) flags |= FAULT_FLAG_WRITE; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); + /* * As per x86, we may deadlock here. However, since the kernel only * validly references user space from well defined areas of the code, @@ -289,7 +292,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) #endif } - fault = __do_page_fault(mm, addr, fsr, flags, tsk); + fault = __do_page_fault(mm, addr, fsr, flags, tsk, regs); /* If we need to retry but a fatal signal is pending, handle the * signal first. We do not need to release the mmap_sem because @@ -301,23 +304,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) return 0; } - /* - * Major/minor page fault accounting is only done on the - * initial attempt. If we go through a retry, it is extremely - * likely that the page will be found in page cache at that point. - */ - - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); if (!(fault & VM_FAULT_ERROR) && flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_MAJOR) { - tsk->maj_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, - regs, addr); - } else { - tsk->min_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, - regs, addr); - } if (fault & VM_FAULT_RETRY) { flags |= FAULT_FLAG_TRIED; goto retry; -- 2.26.2