From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com [IPv6:2607:f8b0:400e:c00::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40dL5z5TNgzDrLk for ; Sat, 5 May 2018 17:26:15 +1000 (AEST) Received: by mail-pf0-x244.google.com with SMTP id a14so19124369pfi.1 for ; Sat, 05 May 2018 00:26:15 -0700 (PDT) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Cc: Nicholas Piggin , Balbir Singh Subject: [PATCH v2 1/2] powerpc/watchdog: don't update the watchdog timestamp if a lockup is detected Date: Sat, 5 May 2018 17:25:59 +1000 Message-Id: <20180505072600.13270-2-npiggin@gmail.com> In-Reply-To: <20180505072600.13270-1-npiggin@gmail.com> References: <20180505072600.13270-1-npiggin@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The watchdog heartbeat timestamp is updated when the local heartbeat timer fires (or touch_nmi_watchdog() is called). This is an interesting data point, so don't overwrite it when the soft-NMI interrupt detects a hard lockup. That code came from a pre- merge version to prevent hard lockup messages flood, but that's taken care of with the stuck CPU logic now, so there is no reason to update the heartbeat timestamp here. Signed-off-by: Nicholas Piggin --- arch/powerpc/kernel/watchdog.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c index 6256dc3b0087..0bc701f9ab35 100644 --- a/arch/powerpc/kernel/watchdog.c +++ b/arch/powerpc/kernel/watchdog.c @@ -245,8 +245,6 @@ void soft_nmi_interrupt(struct pt_regs *regs) tb = get_tb(); if (tb - per_cpu(wd_timer_tb, cpu) >= wd_panic_timeout_tb) { - per_cpu(wd_timer_tb, cpu) = tb; - wd_smp_lock(&flags); if (cpumask_test_cpu(cpu, &wd_smp_cpus_stuck)) { wd_smp_unlock(&flags); -- 2.17.0