From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sat, 12 Dec 2020 12:58:41 -0000 From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org Subject: [tip: irq/core] genirq: Annotate irq stats data races In-Reply-To: <20201210194043.067097663@linutronix.de> References: <20201210194043.067097663@linutronix.de> MIME-Version: 1.0 Message-ID: <160777792105.3364.9820233761878732243.tip-bot2@tip-bot2> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit List-ID: To: linux-tip-commits@vger.kernel.org Cc: Thomas Gleixner , x86@kernel.org, linux-kernel@vger.kernel.org, maz@kernel.org The following commit has been merged into the irq/core branch of tip: Commit-ID: fb4f676fc901cb547226efb3e69ffeaeefa124be Gitweb: https://git.kernel.org/tip/fb4f676fc901cb547226efb3e69ffeaeefa124be Author: Thomas Gleixner AuthorDate: Thu, 10 Dec 2020 20:25:41 +01:00 Committer: Thomas Gleixner CommitterDate: Sat, 12 Dec 2020 12:59:03 +01:00 genirq: Annotate irq stats data races 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 Link: https://lore.kernel.org/r/20201210194043.067097663@linutronix.de --- kernel/irq/irqdesc.c | 4 ++-- kernel/irq/proc.c | 5 +++-- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index f309869..d28f69e 100644 --- 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; } diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 72513ed..9813878 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -488,9 +488,10 @@ int show_interrupts(struct seq_file *p, void *v) 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;