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=-10.1 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 36F65C433DF for ; Fri, 26 Jun 2020 22:32:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F4342088E for ; Fri, 26 Jun 2020 22:32:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EXif4RYx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726409AbgFZWcX (ORCPT ); Fri, 26 Jun 2020 18:32:23 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:46306 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725909AbgFZWbm (ORCPT ); Fri, 26 Jun 2020 18:31:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593210700; 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=EXif4RYxvKQNTLe3gg5/EU/LAccXzI2ZAleGfEKf8nWFuJ7zDU/RCDg2DZvzYsSZqlly31 Ovc+LRAsk55wBmVTAbAJi5s/9drQFpp851dJyVY/o5Nrmvlko+kZvQ2aUTu6g3GiThm1Nx mabTcs7zRGpEICi3DGJgDWaoZwVzD2c= Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-224-Y_JiP7BsOLy_kpcul6x5cg-1; Fri, 26 Jun 2020 18:31:39 -0400 X-MC-Unique: Y_JiP7BsOLy_kpcul6x5cg-1 Received: by mail-qk1-f198.google.com with SMTP id p206so1645530qke.10 for ; Fri, 26 Jun 2020 15:31:39 -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=BMRjPzkAC8bXfKgaC3EalSzpjBU8WjmKOY+3TCIIH7Fnus/o8HUTrSt2aZKjZs5cHB Iyu5IFEMwSGmZf/NVZ5W9dn8fTWg9oGIe7tsUQ0fIP3qRF/8Ql1uDWOgyMEOQiWsElGW el7rZ7GjjzODF/XoqnE6JAd5qLILZkAwiDcv5G+7MD+mshdqgK9HPtLDifPjDvwMSkd6 8kVMjZXdrhvICkda1UlU3A0RjMrAxjXTZ51SS7xA39SnZAFPGrgCfze+75OXDeVhzdXd jon1dSi2YD4lpVLrcxGvunZt4q/Z+BqXcSzSocMHBWC+tKX6vPZyI0wjPQC5M62UbWUh KitQ== X-Gm-Message-State: AOAM531C+oQOqlP0k3QolT5V87INKj34XviqZP3K7k1cOLYD+bKhDD65 53HFem9reXIgFg5pKCPV/Oba7qt4soIsWCelUHdfltzacKnqEYYkoj5+VtLfv0o+0XElikm4uNs XOvulbDfq545Wf+1mkppctSID X-Received: by 2002:ac8:674c:: with SMTP id n12mr1720499qtp.312.1593210698648; Fri, 26 Jun 2020 15:31:38 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwO0yRN7CMv/OFP4YUTmRxOmwQIc3TG0C2j9mstmrYAwNOCl8Vo8qeqsTy1tVWlG77fWkMn/A== X-Received: by 2002:ac8:674c:: with SMTP id n12mr1720484qtp.312.1593210698435; Fri, 26 Jun 2020 15:31:38 -0700 (PDT) Received: from xz-x1.redhat.com ([2607:9880:19c0:32::2]) by smtp.gmail.com with ESMTPSA id f203sm9903311qke.135.2020.06.26.15.31.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Jun 2020 15:31:37 -0700 (PDT) From: Peter Xu To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Linus Torvalds , Gerald Schaefer , Andrea Arcangeli , Will Deacon , peterx@redhat.com, Michael Ellerman , Russell King , linux-arm-kernel@lists.infradead.org Subject: [PATCH 04/26] mm/arm: Use general page fault accounting Date: Fri, 26 Jun 2020 18:31:08 -0400 Message-Id: <20200626223130.199227-5-peterx@redhat.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200626223130.199227-1-peterx@redhat.com> References: <20200626223130.199227-1-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