Commit-ID: ab5fe3ff38ff9653490910cc71dbbedc95a86e41 Gitweb: http://git.kernel.org/tip/ab5fe3ff38ff9653490910cc71dbbedc95a86e41 Author: Thomas Gleixner <[email protected]> AuthorDate: Tue, 12 Sep 2017 21:37:23 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 14 Sep 2017 11:41:09 +0200
watchdog/hardlockup: Clean up hotplug locking mess All watchdog thread related functions are delegated to the smpboot thread infrastructure, which handles serialization against CPU hotplug correctly. The sysctl interface is completely decoupled from anything which requires CPU hotplug protection. No need to protect the sysctl writes against cpu hotplug anymore. Remove it and add the now required protection to the powerpc arch_nmi_watchdog implementation. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Don Zickus <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Sebastian Siewior <[email protected]> Cc: Ulrich Obergfell <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/powerpc/kernel/watchdog.c | 2 ++ kernel/watchdog.c | 6 ------ 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c index 291af79..dfb0677 100644 --- a/arch/powerpc/kernel/watchdog.c +++ b/arch/powerpc/kernel/watchdog.c @@ -359,6 +359,7 @@ void watchdog_nmi_reconfigure(bool run) { int cpu; + cpus_read_lock(); if (!run) { for_each_cpu(cpu, &wd_cpus_enabled) stop_wd_on_cpu(cpu); @@ -367,6 +368,7 @@ void watchdog_nmi_reconfigure(bool run) for_each_cpu_and(cpu, cpu_online_mask, &watchdog_cpumask) start_wd_on_cpu(cpu); } + cpus_read_unlock(); } /* diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 5eb1196..f6ef163 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -664,7 +664,6 @@ static int proc_watchdog_common(int which, struct ctl_table *table, int write, { int err, old, *param = table->data; - cpu_hotplug_disable(); mutex_lock(&watchdog_mutex); if (!write) { @@ -681,7 +680,6 @@ static int proc_watchdog_common(int which, struct ctl_table *table, int write, proc_watchdog_update(); } mutex_unlock(&watchdog_mutex); - cpu_hotplug_enable(); return err; } @@ -725,7 +723,6 @@ int proc_watchdog_thresh(struct ctl_table *table, int write, { int err, old; - cpu_hotplug_disable(); mutex_lock(&watchdog_mutex); old = READ_ONCE(watchdog_thresh); @@ -735,7 +732,6 @@ int proc_watchdog_thresh(struct ctl_table *table, int write, proc_watchdog_update(); mutex_unlock(&watchdog_mutex); - cpu_hotplug_enable(); return err; } @@ -750,7 +746,6 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write, { int err; - cpu_hotplug_disable(); mutex_lock(&watchdog_mutex); err = proc_do_large_bitmap(table, write, buffer, lenp, ppos); @@ -758,7 +753,6 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write, proc_watchdog_update(); mutex_unlock(&watchdog_mutex); - cpu_hotplug_enable(); return err; } #endif /* CONFIG_SYSCTL */
