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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 A9BD0C07E95 for ; Tue, 20 Jul 2021 06:11:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81027610FB for ; Tue, 20 Jul 2021 06:11:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234306AbhGTFbE (ORCPT ); Tue, 20 Jul 2021 01:31:04 -0400 Received: from mx425.baidu.com ([119.249.100.233]:52617 "EHLO mx423.baidu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S230414AbhGTFa1 (ORCPT ); Tue, 20 Jul 2021 01:30:27 -0400 X-Greylist: delayed 382 seconds by postgrey-1.27 at vger.kernel.org; Tue, 20 Jul 2021 01:30:27 EDT Received: from unknown.domain.tld (bjhw-sys-rpm015653cc5.bjhw.baidu.com [10.227.53.39]) by mx423.baidu.com (Postfix) with ESMTP id 5B2C716E01287; Tue, 20 Jul 2021 14:04:41 +0800 (CST) From: Li RongQing To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.co, linux-kernel@vger.kernel.org, songmuchun@bytedance.com Subject: [PATCH][RFC] sched/cpuacct: Fix cpuacct charge Date: Tue, 20 Jul 2021 14:04:41 +0800 Message-Id: <20210720060441.22550-1-lirongqing@baidu.com> X-Mailer: git-send-email 2.9.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org get_irq_regs only work for current running cpu, but the task, whose cpuacct will be charged, maybe run different cpu, like Cpu 2 wake up a kernel thread to CPU 3, cause CPU 3 task are charged with the following stack cpuacct_charge+0xd8/0x100 update_curr+0xe1/0x1e0 enqueue_entity+0x144/0x6e0 enqueue_task_fair+0x93/0x900 ttwu_do_activate+0x4b/0x90 try_to_wake_up+0x20b/0x530 ? update_dl_rq_load_avg+0x10f/0x210 swake_up_locked.part.1+0x13/0x40 swake_up_one+0x27/0x40 rcu_process_callbacks+0x484/0x4f0 ? run_rebalance_domains_bt+0x5a/0x180 __do_softirq+0xe3/0x308 irq_exit+0xf0/0x100 smp_apic_timer_interrupt+0x74/0x160 apic_timer_interrupt+0xf/0x20 RIP: 0033:0x456947 so define a get_irq_regs_cpu which returns the required cpu irq registers BUT it should be not safe, and do not know what it should be like in MIPS? Fixes: dbe9337109c2 "(sched/cpuacct: Fix charge cpuacct.usage_sys)" Co-developed-by: Zhao Jie Signed-off-by: Zhao Jie Signed-off-by: Li RongQing --- include/asm-generic/irq_regs.h | 5 +++++ kernel/sched/cpuacct.c | 3 ++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/include/asm-generic/irq_regs.h b/include/asm-generic/irq_regs.h index 2e7c6e8..93e2579 100644 --- a/include/asm-generic/irq_regs.h +++ b/include/asm-generic/irq_regs.h @@ -21,6 +21,11 @@ static inline struct pt_regs *get_irq_regs(void) return __this_cpu_read(__irq_regs); } +static inline struct pt_regs *get_irq_regs_cpu(int cpu) +{ + return per_cpu(__irq_regs, cpu); +} + static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs) { struct pt_regs *old_regs; diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 893eece..8b96058 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -340,7 +340,8 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime) { struct cpuacct *ca; int index = CPUACCT_STAT_SYSTEM; - struct pt_regs *regs = get_irq_regs() ? : task_pt_regs(tsk); + int cpu = task_cpu(tsk); + struct pt_regs *regs = get_irq_regs_cpu(cpu) ? : task_pt_regs(tsk); if (regs && user_mode(regs)) index = CPUACCT_STAT_USER; -- 2.9.4