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=ham 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 91830C433DF for ; Tue, 7 Jul 2020 22:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E13C2075B for ; Tue, 7 Jul 2020 22:51:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iTHnZcLA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729579AbgGGWui (ORCPT ); Tue, 7 Jul 2020 18:50:38 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:49135 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729535AbgGGWuf (ORCPT ); Tue, 7 Jul 2020 18:50:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594162233; 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=D8OdeaID5or5gsgcWoj3vmPJjBIrXv0E7kOuYlamE1o=; b=iTHnZcLAXbSFJJvtASJ9bLC/f0KBB4I88Enw1PSHF4wVyEB//evWo5EQLCcKhDxHXUvEoY +Il7MRLBL1i9/nFDNWnm6tO9+syLN9pbcU2DGKN7jkL6u5eMqrIP60sXFWGN432sZuiv4n nl2l4bFeWaYCOVuNI79JXUjKShjCTpc= Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-38-niBE3u_7ObG-EVBnj2YPgQ-1; Tue, 07 Jul 2020 18:50:32 -0400 X-MC-Unique: niBE3u_7ObG-EVBnj2YPgQ-1 Received: by mail-qt1-f198.google.com with SMTP id t36so13852461qtc.16 for ; Tue, 07 Jul 2020 15:50:31 -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=D8OdeaID5or5gsgcWoj3vmPJjBIrXv0E7kOuYlamE1o=; b=QcgzmL0eYWfTr1YPvZru0XfEh2c1GW/0aPwqmynivChkeKatOiTcokGoQGmgseHbJy CBsDw9kQ0OEvqkz+AN4+a/G8ptroJF7ltwnPbbggMQcrgvvc9lQPteqQhby2Dnk5zOOe nxC4mqaBG1vqM7tk2O2NYoRghKkCXwycdvXLpR5OlUYrkQGY6k8JOQmwQ6sBLNKuPg78 tpl6hbQWL2c72Lq8GXeif589oMPOZl4sTxjG+8Oltb1LcqIPIndwIcfK6KfcCna3lfX2 5RMFIf6DS6VKEsTe18xUQgL2xsUAp8guvp+oqWq5VNcEScvUitw93OkolImyCpYxm+gC WDhw== X-Gm-Message-State: AOAM5316s+smhEFwrLDFyuwhuzIR9XTUYxud2Zph0w/ZJkrsRhhXrEnW uT01+vnTFHh54+V1FIlj/Mj0IfTz5KVlJz+oShahX4qernmwls5406pgRUSmK4bR639bWKzIIET PTUg/r5s84otk3M61ljCjOhrg X-Received: by 2002:ac8:4419:: with SMTP id j25mr59295048qtn.0.1594162231218; Tue, 07 Jul 2020 15:50:31 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwz8DXKkHPxoOFEcQD6pHkWkgMOJfaMYF0tKBmTSmaZQNpqDRHsJem4bnZngb+YYMsixKQJtw== X-Received: by 2002:ac8:4419:: with SMTP id j25mr59295024qtn.0.1594162230982; Tue, 07 Jul 2020 15:50:30 -0700 (PDT) Received: from xz-x1.redhat.com ([2607:9880:19c0:32::2]) by smtp.gmail.com with ESMTPSA id j16sm26267642qtp.92.2020.07.07.15.50.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 15:50:30 -0700 (PDT) From: Peter Xu To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Gerald Schaefer , Linus Torvalds , peterx@redhat.com, Andrew Morton , Will Deacon , Andrea Arcangeli , David Rientjes , John Hubbard , Michael Ellerman , Russell King , linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 04/25] mm/arm: Use general page fault accounting Date: Tue, 7 Jul 2020 18:50:00 -0400 Message-Id: <20200707225021.200906-5-peterx@redhat.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200707225021.200906-1-peterx@redhat.com> References: <20200707225021.200906-1-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 01a8e0f8fef7..efa402025031 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -202,7 +202,8 @@ 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; @@ -224,7 +225,7 @@ __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 */ @@ -266,6 +267,8 @@ 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, @@ -290,7 +293,7 @@ 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_lock because @@ -302,23 +305,7 @@ 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