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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Borislav Petkov <bp@alien8.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Sebastian Siewior <bigeasy@linutronix.de>,
	Nicholas Piggin <npiggin@gmail.com>,
	Don Zickus <dzickus@redhat.com>,
	Chris Metcalf <cmetcalf@mellanox.com>,
	Ulrich Obergfell <uobergfe@redhat.com>
Subject: [patch V2 18/29] lockup_detector: Further simplify sysctl handling
Date: Tue, 12 Sep 2017 21:37:12 +0200
Message-ID: <20170912194147.549114957@linutronix.de> (raw)
In-Reply-To: <20170912193654.321505854@linutronix.de>


[-- Attachment #0: lockup_detector_Further_simplify_sysctl_handling.patch --]
[-- Type: text/plain, Size: 3063 bytes --]

Use a single function to update sysctl changes. This is not a high
frequency user space interface and it's root only.

Preparatory patch to cleanup the sysctl variable handling.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20170831073054.426780446@linutronix.de

---
 kernel/watchdog.c |   27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -507,11 +507,8 @@ static void softlockup_park_all_threads(
 	softlockup_update_smpboot_threads();
 }
 
-/*
- * Park threads which are not longer enabled and unpark threads which have
- * been newly enabled.
- */
-static void softlockup_update_threads(void)
+/* Unpark enabled threads */
+static void softlockup_unpark_threads(void)
 {
 	cpumask_copy(&watchdog_allowed_mask, &watchdog_cpumask);
 	softlockup_update_smpboot_threads();
@@ -522,7 +519,7 @@ static void softlockup_reconfigure_threa
 	softlockup_park_all_threads();
 	set_sample_period();
 	if (enabled)
-		softlockup_update_threads();
+		softlockup_unpark_threads();
 }
 
 /*
@@ -563,7 +560,6 @@ static inline void watchdog_unpark_threa
 static inline int watchdog_enable_all_cpus(void) { return 0; }
 static inline void watchdog_disable_all_cpus(void) { }
 static inline void softlockup_init_threads(void) { }
-static inline void softlockup_update_threads(void) { }
 static inline void softlockup_reconfigure_threads(bool enabled) { }
 #endif /* !CONFIG_SOFTLOCKUP_DETECTOR */
 
@@ -598,11 +594,11 @@ void lockup_detector_soft_poweroff(void)
 
 #ifdef CONFIG_SYSCTL
 
-/*
- * Update the run state of the lockup detectors.
- */
+/* Propagate any changes to the watchdog threads */
 static void proc_watchdog_update(void)
 {
+	/* Remove impossible cpus to keep sysctl output clean. */
+	cpumask_and(&watchdog_cpumask, &watchdog_cpumask, cpu_possible_mask);
 	softlockup_reconfigure_threads(watchdog_enabled && watchdog_thresh);
 	watchdog_nmi_reconfigure();
 }
@@ -721,15 +717,6 @@ int proc_watchdog_thresh(struct ctl_tabl
 	return err;
 }
 
-static void proc_watchdog_cpumask_update(void)
-{
-	/* Remove impossible cpus to keep sysctl output clean. */
-	cpumask_and(&watchdog_cpumask, &watchdog_cpumask, cpu_possible_mask);
-
-	softlockup_update_threads();
-	watchdog_nmi_reconfigure();
-}
-
 /*
  * The cpumask is the mask of possible cpus that the watchdog can run
  * on, not the mask of cpus it is actually running on.  This allows the
@@ -746,7 +733,7 @@ int proc_watchdog_cpumask(struct ctl_tab
 
 	err = proc_do_large_bitmap(table, write, buffer, lenp, ppos);
 	if (!err && write)
-		proc_watchdog_cpumask_update();
+		proc_watchdog_update();
 
 	mutex_unlock(&watchdog_mutex);
 	cpu_hotplug_enable();

  parent reply index

Thread overview: 77+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-12 19:36 [patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Thomas Gleixner
2017-09-12 19:36 ` [patch V2 01/29] hardlockup_detector: Provide interface to stop/restart perf events Thomas Gleixner
2017-09-14 10:40   ` [tip:core/urgent] watchdog/hardlockup: " tip-bot for Peter Zijlstra
2017-09-12 19:36 ` [patch V2 02/29] perf/x86/intel: Sanitize PMU HT bug workaround Thomas Gleixner
2017-09-14 10:40   ` [tip:core/urgent] perf/x86/intel, watchdog/core: " tip-bot for Peter Zijlstra
2017-09-12 19:36 ` [patch V2 03/29] lockup_detector: Provide interface to stop from poweroff() Thomas Gleixner
2017-09-14 10:40   ` [tip:core/urgent] watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:36 ` [patch V2 04/29] parisc: Use lockup_detector_stop() Thomas Gleixner
2017-09-14  8:59   ` Helge Deller
2017-09-14 13:46     ` Don Zickus
2017-09-14 10:41   ` [tip:core/urgent] parisc, watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:36 ` [patch V2 05/29] lockup_detector: Remove broken suspend/resume interfaces Thomas Gleixner
2017-09-14 10:41   ` [tip:core/urgent] watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 06/29] lockup_detector: Rework cpu hotplug locking Thomas Gleixner
2017-09-14 10:41   ` [tip:core/urgent] watchdog/core: Rework CPU " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 07/29] lockup_detector: Rename watchdog_proc_mutex Thomas Gleixner
2017-09-14 10:42   ` [tip:core/urgent] watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 08/29] lockup_detector: Mark hardlockup_detector_disable() __init Thomas Gleixner
2017-09-14 10:42   ` [tip:core/urgent] watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 09/29] lockup_detector/perf: Remove broken self disable on failure Thomas Gleixner
2017-09-14 10:43   ` [tip:core/urgent] watchdog/hardlockup/perf: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 10/29] lockup_detector/perf: Prevent cpu hotplug deadlock Thomas Gleixner
2017-09-14 10:43   ` [tip:core/urgent] watchdog/hardlockup/perf: Prevent CPU " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 11/29] lockup_detector: Remove park_in_progress obfuscation Thomas Gleixner
2017-09-12 19:37 ` [patch V2 12/29] lockup_detector: Cleanup stub functions Thomas Gleixner
2017-09-14 10:44   ` [tip:core/urgent] watchdog/core: Clean up " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 13/29] lockup_detector: Cleanup the ifdef maze Thomas Gleixner
2017-09-14 10:44   ` [tip:core/urgent] watchdog/core: Clean up the #ifdef maze tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 14/29] lockup_detector: Split out cpumask write function Thomas Gleixner
2017-09-14 10:45   ` [tip:core/urgent] watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 15/29] smpboot/threads: Avoid runtime allocation Thomas Gleixner
2017-09-14 10:45   ` [tip:core/urgent] smpboot/threads, watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 16/29] lockup_detector: Create new thread handling infrastructure Thomas Gleixner
2017-09-14 10:45   ` [tip:core/urgent] watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 17/29] lockup_detector: Get rid of the thread teardown/setup dance Thomas Gleixner
2017-09-14 10:46   ` [tip:core/urgent] watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` Thomas Gleixner [this message]
2017-09-14 10:46   ` [tip:core/urgent] watchdog/core: Further simplify sysctl handling tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 19/29] lockup_detector: Cleanup header mess Thomas Gleixner
2017-09-14 10:47   ` [tip:core/urgent] watchdog/core: Clean up " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 20/29] lockup_detector/sysctl: Get rid of the ifdeffery Thomas Gleixner
2017-09-14 10:47   ` [tip:core/urgent] watchdog/sysctl: Get rid of the #ifdeffery tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 21/29] lockup_detector: Cleanup sysctl variable name space Thomas Gleixner
2017-09-14 10:47   ` [tip:core/urgent] watchdog/sysctl: Clean up " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 22/29] lockup_detector: Make watchdog_nmi_reconfigure() two stage Thomas Gleixner
2017-09-14 10:48   ` [tip:core/urgent] watchdog/core, powerpc: " tip-bot for Thomas Gleixner
2017-10-03  0:29   ` [patch V2 22/29] lockup_detector: " Michael Ellerman
2017-10-03  6:50     ` Thomas Gleixner
2017-10-03  7:04       ` Thomas Gleixner
2017-10-03 10:01         ` Nicholas Piggin
2017-10-03 10:56           ` Thomas Gleixner
2017-10-03 11:36       ` Michael Ellerman
2017-10-03 12:13         ` Thomas Gleixner
2017-10-03 13:20           ` Thomas Gleixner
2017-10-03 19:27             ` Thomas Gleixner
2017-10-04  5:53               ` Michael Ellerman
2017-10-05 16:17               ` Don Zickus
2017-09-12 19:37 ` [patch V2 23/29] lockup_detector: Get rid of the racy update loop Thomas Gleixner
2017-09-14 10:48   ` [tip:core/urgent] watchdog/core: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 24/29] lockup_detector/perf: Implement init time perf validation Thomas Gleixner
2017-09-14 10:48   ` [tip:core/urgent] watchdog/hardlockup/perf: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 25/29] lockup_detector: Implement init time detection of perf Thomas Gleixner
2017-09-13 18:02   ` Don Zickus
2017-09-13 18:05     ` Thomas Gleixner
2017-09-14  5:27       ` Ingo Molnar
2017-09-14 10:49   ` [tip:core/urgent] watchdog/hardlockup/perf: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 26/29] lockup_detector/perf: Implement CPU enable replacement Thomas Gleixner
2017-09-14 10:49   ` [tip:core/urgent] watchdog/hardlockup/perf: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 27/29] lockup_detector: Use new perf CPU enable mechanism Thomas Gleixner
2017-09-14 10:50   ` [tip:core/urgent] watchdog/hardlockup/perf: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 28/29] lockup_detector/perf: Simplify deferred event destroy Thomas Gleixner
2017-09-14 10:50   ` [tip:core/urgent] watchdog/hardlockup/perf: " tip-bot for Thomas Gleixner
2017-09-12 19:37 ` [patch V2 29/29] lockup_detector: Cleanup hotplug locking mess Thomas Gleixner
2017-09-14 10:50   ` [tip:core/urgent] watchdog/hardlockup: Clean up " tip-bot for Thomas Gleixner
2017-09-13 18:06 ` [patch V2 00/29] lockup_detector: Cure hotplug deadlocks and replace duct tape Don Zickus
2017-09-14  5:27   ` Ingo Molnar
2017-09-14  8:11   ` Thomas Gleixner

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