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Groups > linux.kernel > #1732197
| From | tip-bot for Thomas Gleixner <tipbot@zytor.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [tip:core/urgent] watchdog/hardlockup: Clean up hotplug locking mess |
| Date | 2017-09-14 13:00 +0200 |
| Message-ID | <upA2e-3WF-11@gated-at.bofh.it> (permalink) |
| References | <uoZvI-5zK-23@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Commit-ID: ab5fe3ff38ff9653490910cc71dbbedc95a86e41
Gitweb: http://git.kernel.org/tip/ab5fe3ff38ff9653490910cc71dbbedc95a86e41
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 12 Sep 2017 21:37:23 +0200
Committer: Ingo Molnar <mingo@kernel.org>
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 <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170912194148.418497420@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
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 */
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[patch V2 14/29] lockup_detector: Split out cpumask write function Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[tip:core/urgent] watchdog/core: Split out cpumask write function tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 05/29] lockup_detector: Remove broken suspend/resume interfaces Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[tip:core/urgent] watchdog/core: Remove broken suspend/resume interfaces tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 16/29] lockup_detector: Create new thread handling infrastructure Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[tip:core/urgent] watchdog/core: Create new thread handling infrastructure tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 01/29] hardlockup_detector: Provide interface to stop/restart perf events Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 21:50 +0200
[tip:core/urgent] watchdog/hardlockup: Provide interface to stop/restart perf events tip-bot for Peter Zijlstra <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 26/29] lockup_detector/perf: Implement CPU enable replacement Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Implement CPU enable replacement tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 06/29] lockup_detector: Rework cpu hotplug locking Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Rework CPU hotplug locking tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 28/29] lockup_detector/perf: Simplify deferred event destroy Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Simplify deferred event destroy tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 04/29] parisc: Use lockup_detector_stop() Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
Re: [patch V2 04/29] parisc: Use lockup_detector_stop() Helge Deller <deller@gmx.de> - 2017-09-14 11:10 +0200
Re: [patch V2 04/29] parisc: Use lockup_detector_stop() Don Zickus <dzickus@redhat.com> - 2017-09-14 15:50 +0200
[tip:core/urgent] parisc, watchdog/core: Use lockup_detector_stop() tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 17/29] lockup_detector: Get rid of the thread teardown/setup dance Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Get rid of the thread teardown/setup dance tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 03/29] lockup_detector: Provide interface to stop from poweroff() Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Provide interface to stop from poweroff() tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 10/29] lockup_detector/perf: Prevent cpu hotplug deadlock Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Prevent CPU hotplug deadlock tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 13/29] lockup_detector: Cleanup the ifdef maze Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Clean up the #ifdef maze tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 29/29] lockup_detector: Cleanup hotplug locking mess Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup: Clean up hotplug locking mess tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 09/29] lockup_detector/perf: Remove broken self disable on failure Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Remove broken self disable on failure tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 08/29] lockup_detector: Mark hardlockup_detector_disable() __init Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Mark hardlockup_detector_disable() __init tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 12:50 +0200
[patch V2 18/29] lockup_detector: Further simplify sysctl handling Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Further simplify sysctl handling tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 12/29] lockup_detector: Cleanup stub functions Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Clean up stub functions tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 15/29] smpboot/threads: Avoid runtime allocation Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] smpboot/threads, watchdog/core: Avoid runtime allocation tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 20/29] lockup_detector/sysctl: Get rid of the ifdeffery Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/sysctl: Get rid of the #ifdeffery tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 27/29] lockup_detector: Use new perf CPU enable mechanism Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Use new perf CPU enable mechanism tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 24/29] lockup_detector/perf: Implement init time perf validation Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Implement init time perf validation tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 19/29] lockup_detector: Cleanup header mess Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Clean up header mess tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 22/29] lockup_detector: Make watchdog_nmi_reconfigure() two stage Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 25/29] lockup_detector: Implement init time detection of perf Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
Re: [patch V2 25/29] lockup_detector: Implement init time detection of perf Don Zickus <dzickus@redhat.com> - 2017-09-13 20:10 +0200
Re: [patch V2 25/29] lockup_detector: Implement init time detection of perf Thomas Gleixner <tglx@linutronix.de> - 2017-09-13 20:10 +0200
Re: [patch V2 25/29] lockup_detector: Implement init time detection of perf Ingo Molnar <mingo@kernel.org> - 2017-09-14 07:30 +0200
[tip:core/urgent] watchdog/hardlockup/perf: Implement init time detection of perf tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
[patch V2 23/29] lockup_detector: Get rid of the racy update loop Thomas Gleixner <tglx@linutronix.de> - 2017-09-12 22:00 +0200
[tip:core/urgent] watchdog/core: Get rid of the racy update loop tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-09-14 13:00 +0200
Re: [patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Don Zickus <dzickus@redhat.com> - 2017-09-13 20:10 +0200
Re: [patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Ingo Molnar <mingo@kernel.org> - 2017-09-14 07:30 +0200
Re: [patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Thomas Gleixner <tglx@linutronix.de> - 2017-09-14 10:20 +0200
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