From nobody Tue Feb 10 02:43:43 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32F36C7EE2A for ; Fri, 19 May 2023 17:22:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231971AbjESRWD (ORCPT ); Fri, 19 May 2023 13:22:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231840AbjESRVe (ORCPT ); Fri, 19 May 2023 13:21:34 -0400 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64BD8198A for ; Fri, 19 May 2023 10:21:12 -0700 (PDT) Received: by mail-pl1-x631.google.com with SMTP id d9443c01a7336-1ae58e4b295so22081895ad.2 for ; Fri, 19 May 2023 10:21:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1684516871; x=1687108871; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=IuTIR6+6K+hxxUnbYOqT244lVUkQITd3O6ucqubZZl4=; b=CX33eL4GdlRvEhb7MRrK0HcpGqL14uaialqiwAf8d9nqYwj101HteFwTQXh3a2ruOf lhf5cbylszXdV2cL38Sy9TAJNoiBIz9POYMeDG2sKqgFReGRdJWhtFAIAZWTFwMsot5m qhaAjIgBIvHfv42zEE37qt4WUUod5wAV5uRIY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684516871; x=1687108871; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=IuTIR6+6K+hxxUnbYOqT244lVUkQITd3O6ucqubZZl4=; b=RvIX0X6MzUF131+6rkHvIL75rqHl7Z8houAQXoM5RBVu61y/V1OGVPH73iAYAacURk FiqR9E3cizFKO+zwIVwj0Jtcn5VGt6Kqiq+yvZJh3P28KF/fn7v7wrxPHbc8bK7Wt6lP jgni+wYQLQInxHaXX3cx8vq6GHzIXaSZLPFuPfNcOTPqJ45FXCVTbtsUnzCqjA4Wl+7F w0BXhrmdpk24xLDEH26itsS7Tef7gNrGlixFdrERcH17TBSo+lVd1XdbKDPQEtjcPcrd 45UzEsZutCnBKq6GLLrADRj3swySSnBHh0i5ORuFWM6rdV50BZ3I9VH5RUhgcPYVjkkI T+nw== X-Gm-Message-State: AC+VfDwGd4DUPnot0+KqBu8FUDAvJYYe4ION5JFoZykvQbRN/BnKiAwe BId7jtF0qJyU0nDxqg0hA12axw== X-Google-Smtp-Source: ACHHUZ6ZU/Zv+5uWQsHIPpE4gUjVmcZg9+Jv3yXZssM4t7jGD7GgABZwIzSWfBu1QwcX6vPL39vSYQ== X-Received: by 2002:a17:902:c945:b0:1a9:546c:1593 with SMTP id i5-20020a170902c94500b001a9546c1593mr4356324pla.14.1684516871096; Fri, 19 May 2023 10:21:11 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:9d:2:9b89:2dd0:d160:429d]) by smtp.gmail.com with ESMTPSA id gj19-20020a17090b109300b0024e4f169931sm1763835pjb.2.2023.05.19.10.21.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 May 2023 10:21:10 -0700 (PDT) From: Douglas Anderson To: Petr Mladek , Andrew Morton Cc: Matthias Kaehlcke , kgdb-bugreport@lists.sourceforge.net, Stephane Eranian , mpe@ellerman.id.au, Tzung-Bi Shih , Daniel Thompson , Mark Rutland , linuxppc-dev@lists.ozlabs.org, Sumit Garg , npiggin@gmail.com, davem@davemloft.net, Marc Zyngier , Stephen Boyd , sparclinux@vger.kernel.org, christophe.leroy@csgroup.eu, Catalin Marinas , ravi.v.shankar@intel.com, Randy Dunlap , Pingfan Liu , Guenter Roeck , Lecopzer Chen , Ian Rogers , ito-yuichi@fujitsu.com, ricardo.neri@intel.com, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, Will Deacon , Chen-Yu Tsai , linux-kernel@vger.kernel.org, Masayoshi Mizuma , Andi Kleen , Douglas Anderson Subject: [PATCH v5 11/18] watchdog/hardlockup: Move perf hardlockup watchdog petting to watchdog.c Date: Fri, 19 May 2023 10:18:35 -0700 Message-ID: <20230519101840.v5.11.I00dfd6386ee00da25bf26d140559a41339b53e57@changeid> X-Mailer: git-send-email 2.40.1.698.g37aff9b760-goog In-Reply-To: <20230519101840.v5.18.Ia44852044cdcb074f387e80df6b45e892965d4a1@changeid> References: <20230519101840.v5.18.Ia44852044cdcb074f387e80df6b45e892965d4a1@changeid> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In preparation for the buddy hardlockup detector, which wants the same petting logic as the current perf hardlockup detector, move the code to watchdog.c. While doing this, rename the global variable to match others nearby. As part of this change we have to change the code to account for the fact that the CPU we're running on might be different than the one we're checking. Currently the code in watchdog.c is guarded by CONFIG_HARDLOCKUP_DETECTOR_PERF, which makes this change seem silly. However, a future patch will change this. Signed-off-by: Douglas Anderson Reviewed-by: Petr Mladek --- Changes in v5: - Fixed wrong __this_cpu to per_cpu (oops). - Move side effect (timestamp check ordering) to its own patch. - watchdog_hardlockup_touch =3D> watchdog_hardlockup_touched. Changes in v4: - ("Move perf hardlockup watchdog petting to watchdog.c") new for v4. include/linux/nmi.h | 5 +++-- kernel/watchdog.c | 19 +++++++++++++++++++ kernel/watchdog_perf.c | 19 ------------------- 3 files changed, 22 insertions(+), 21 deletions(-) diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 92aa568c0c42..e286a2a1902d 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -88,7 +88,10 @@ static inline void hardlockup_detector_disable(void) {} #endif =20 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) +void arch_touch_nmi_watchdog(void); void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs); +#elif !defined(CONFIG_HAVE_NMI_WATCHDOG) +static inline void arch_touch_nmi_watchdog(void) { } #endif =20 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTO= R) @@ -98,7 +101,6 @@ void watchdog_hardlockup_check(unsigned int cpu, struct = pt_regs *regs); #endif =20 #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) -extern void arch_touch_nmi_watchdog(void); extern void hardlockup_detector_perf_stop(void); extern void hardlockup_detector_perf_restart(void); extern void hardlockup_detector_perf_disable(void); @@ -113,7 +115,6 @@ static inline void hardlockup_detector_perf_enable(void= ) { } static inline void hardlockup_detector_perf_cleanup(void) { } # if !defined(CONFIG_HAVE_NMI_WATCHDOG) static inline int hardlockup_detector_perf_init(void) { return -ENODEV; } -static inline void arch_touch_nmi_watchdog(void) {} # else static inline int hardlockup_detector_perf_init(void) { return 0; } # endif diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 2552e224f76a..64d7d2a0a7df 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -90,8 +90,22 @@ __setup("nmi_watchdog=3D", hardlockup_panic_setup); static DEFINE_PER_CPU(atomic_t, hrtimer_interrupts); static DEFINE_PER_CPU(int, hrtimer_interrupts_saved); static DEFINE_PER_CPU(bool, watchdog_hardlockup_warned); +static DEFINE_PER_CPU(bool, watchdog_hardlockup_touched); static unsigned long watchdog_hardlockup_all_cpu_dumped; =20 +notrace void arch_touch_nmi_watchdog(void) +{ + /* + * Using __raw here because some code paths have + * preemption enabled. If preemption is enabled + * then interrupts should be enabled too, in which + * case we shouldn't have to worry about the watchdog + * going off. + */ + raw_cpu_write(watchdog_hardlockup_touched, true); +} +EXPORT_SYMBOL(arch_touch_nmi_watchdog); + static bool is_hardlockup(unsigned int cpu) { int hrint =3D atomic_read(&per_cpu(hrtimer_interrupts, cpu)); @@ -116,6 +130,11 @@ static void watchdog_hardlockup_kick(void) =20 void watchdog_hardlockup_check(unsigned int cpu, struct pt_regs *regs) { + if (per_cpu(watchdog_hardlockup_touched, cpu)) { + per_cpu(watchdog_hardlockup_touched, cpu) =3D false; + return; + } + /* * Check for a hardlockup by making sure the CPU's timer * interrupt is incrementing. The timer interrupt should have diff --git a/kernel/watchdog_perf.c b/kernel/watchdog_perf.c index 4e60e8023515..547917ebd5d3 100644 --- a/kernel/watchdog_perf.c +++ b/kernel/watchdog_perf.c @@ -20,26 +20,12 @@ #include #include =20 -static DEFINE_PER_CPU(bool, watchdog_nmi_touch); static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); static DEFINE_PER_CPU(struct perf_event *, dead_event); static struct cpumask dead_events_mask; =20 static atomic_t watchdog_cpus =3D ATOMIC_INIT(0); =20 -notrace void arch_touch_nmi_watchdog(void) -{ - /* - * Using __raw here because some code paths have - * preemption enabled. If preemption is enabled - * then interrupts should be enabled too, in which - * case we shouldn't have to worry about the watchdog - * going off. - */ - raw_cpu_write(watchdog_nmi_touch, true); -} -EXPORT_SYMBOL(arch_touch_nmi_watchdog); - #ifdef CONFIG_HARDLOCKUP_CHECK_TIMESTAMP static DEFINE_PER_CPU(ktime_t, last_timestamp); static DEFINE_PER_CPU(unsigned int, nmi_rearmed); @@ -115,11 +101,6 @@ static void watchdog_overflow_callback(struct perf_eve= nt *event, if (!watchdog_check_timestamp()) return; =20 - if (__this_cpu_read(watchdog_nmi_touch) =3D=3D true) { - __this_cpu_write(watchdog_nmi_touch, false); - return; - } - watchdog_hardlockup_check(smp_processor_id(), regs); } =20 --=20 2.40.1.698.g37aff9b760-goog