From patchwork Thu Dec 10 19:25:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 11966375 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 8100BC4167B for ; Thu, 10 Dec 2020 20:12:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F41D2332A for ; Thu, 10 Dec 2020 20:12:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393520AbgLJTnD (ORCPT ); Thu, 10 Dec 2020 14:43:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393512AbgLJTnC (ORCPT ); Thu, 10 Dec 2020 14:43:02 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8125FC06179C; Thu, 10 Dec 2020 11:42:22 -0800 (PST) Message-Id: <20201210194043.067097663@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1607629341; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=an/0SlT10gC/rfGB9cofMBAbBc2y8gDRMVN0GHlSQuQ=; b=4P4kE5RTAFQxk4E9p2NZ5tVZaT/fVdqT6FUBVR+n0VlRr8uKLCY6ouByJWK/y9MigmPqnb tesyONzFlkjZdJe1WWdFvx3h+r+GXjLB7sIlmHBZwN8ZTN8764SDWmNv/29J0LI/juCzrG 5AR2DIz8iI4y5+WrS2Gk+rZPh543USYMAHoeudVHDJ9Wges2zOPIJ3rC2brtEkqswFGEBV qoEKpCAHt2vMMptUuKRYjL5+zlSE91zw5P4yyaAjNJTKm8BCJhUlMmWxn/QqILbbs/4fJM zRFVwll3IxpXJvkmkahKFPnuLZWACJTleFizSON231iYySZCGseiBRgkWQqHew== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1607629341; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=an/0SlT10gC/rfGB9cofMBAbBc2y8gDRMVN0GHlSQuQ=; b=0D9iZlJLFfBnhtOaF8MIaZu0T6LGBg7Mhm2UH/Vr6qq568TJA8295HDu2RHkjE+w+f0eVZ +xYpdmSgjdKynXCQ== Date: Thu, 10 Dec 2020 20:25:41 +0100 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Marc Zyngier , "James E.J. Bottomley" , Helge Deller , afzal mohammed , linux-parisc@vger.kernel.org, Russell King , linux-arm-kernel@lists.infradead.org, Mark Rutland , Catalin Marinas , Will Deacon , Christian Borntraeger , Heiko Carstens , linux-s390@vger.kernel.org, Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , Pankaj Bharadiya , Chris Wilson , Wambui Karuga , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Tvrtko Ursulin , Linus Walleij , linux-gpio@vger.kernel.org, Lee Jones , Jon Mason , Dave Jiang , Allen Hubbe , linux-ntb@googlegroups.com, Lorenzo Pieralisi , Rob Herring , Bjorn Helgaas , Michal Simek , linux-pci@vger.kernel.org, Karthikeyan Mitran , Hou Zhiqiang , Tariq Toukan , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-rdma@vger.kernel.org, Saeed Mahameed , Leon Romanovsky , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , xen-devel@lists.xenproject.org Subject: [patch 05/30] genirq: Annotate irq stats data races References: <20201210192536.118432146@linutronix.de> MIME-Version: 1.0 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Both the per cpu stats and the accumulated count are accessed lockless and can be concurrently modified. That's intentional and the stats are a rough estimate anyway. Annotate them with data_race(). Signed-off-by: Thomas Gleixner --- kernel/irq/irqdesc.c | 4 ++-- kernel/irq/proc.c | 5 +++-- 2 files changed, 5 insertions(+), 4 deletions(-) --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -943,10 +943,10 @@ unsigned int kstat_irqs(unsigned int irq if (!irq_settings_is_per_cpu_devid(desc) && !irq_settings_is_per_cpu(desc) && !irq_is_nmi(desc)) - return desc->tot_count; + return data_race(desc->tot_count); for_each_possible_cpu(cpu) - sum += *per_cpu_ptr(desc->kstat_irqs, cpu); + sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu)); return sum; } --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -488,9 +488,10 @@ int show_interrupts(struct seq_file *p, if (!desc || irq_settings_is_hidden(desc)) goto outsparse; - if (desc->kstat_irqs) + if (desc->kstat_irqs) { for_each_online_cpu(j) - any_count |= *per_cpu_ptr(desc->kstat_irqs, j); + any_count |= data_race(*per_cpu_ptr(desc->kstat_irqs, j)); + } if ((!desc->action || irq_desc_is_chained(desc)) && !any_count) goto outsparse;