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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 EB5FAC64EB0 for ; Tue, 9 Oct 2018 22:08:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0A0720C0A for ; Tue, 9 Oct 2018 22:08:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A0A0720C0A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728004AbeJJF1t (ORCPT ); Wed, 10 Oct 2018 01:27:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57636 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726781AbeJJF1t (ORCPT ); Wed, 10 Oct 2018 01:27:49 -0400 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id B3E75A85; Tue, 9 Oct 2018 22:08:46 +0000 (UTC) Date: Tue, 9 Oct 2018 15:08:45 -0700 From: Andrew Morton To: Johannes Weiner Cc: Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 3/4] mm: workingset: add vmstat counter for shadow nodes Message-Id: <20181009150845.8656eb8ede045ca5f4cc4b21@linux-foundation.org> In-Reply-To: <20181009184732.762-4-hannes@cmpxchg.org> References: <20181009184732.762-1-hannes@cmpxchg.org> <20181009184732.762-4-hannes@cmpxchg.org> X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 9 Oct 2018 14:47:32 -0400 Johannes Weiner wrote: > --- a/mm/workingset.c > +++ b/mm/workingset.c > @@ -378,11 +378,17 @@ void workingset_update_node(struct xa_node *node) > * as node->private_list is protected by the i_pages lock. > */ > if (node->count && node->count == node->nr_values) { > - if (list_empty(&node->private_list)) > + if (list_empty(&node->private_list)) { > list_lru_add(&shadow_nodes, &node->private_list); > + __inc_lruvec_page_state(virt_to_page(node), > + WORKINGSET_NODES); > + } > } else { > - if (!list_empty(&node->private_list)) > + if (!list_empty(&node->private_list)) { > list_lru_del(&shadow_nodes, &node->private_list); > + __dec_lruvec_page_state(virt_to_page(node), > + WORKINGSET_NODES); > + } > } > } A bit worried that we're depending on the caller's caller to have disabled interrupts to avoid subtle and rare errors. Can we do this? --- a/mm/workingset.c~mm-workingset-add-vmstat-counter-for-shadow-nodes-fix +++ a/mm/workingset.c @@ -377,6 +377,8 @@ void workingset_update_node(struct radix * already where they should be. The list_empty() test is safe * as node->private_list is protected by the i_pages lock. */ + WARN_ON_ONCE(!irqs_disabled()); /* For __inc_lruvec_page_state */ + if (node->count && node->count == node->exceptional) { if (list_empty(&node->private_list)) { list_lru_add(&shadow_nodes, &node->private_list); _