path: root/arch
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-10-06 08:36:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-10-06 08:36:41 -0700
commit27efed3e8384e4d87fe3c07e7a046c1f43eb0993 (patch)
tree96d45ac3bfd2c0009dad5b23387da801ce7203e1 /arch
parentMerge tag 'pm-4.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm (diff)
parentwatchdog/core: Put softlockup_threads_initialized under ifdef guard (diff)
Merge branch 'core-watchdog-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull watchddog clean-up and fixes from Thomas Gleixner: "The watchdog (hard/softlockup detector) code is pretty much broken in its current state. The patch series addresses this by removing all duct tape and refactoring it into a workable state. The reasons why I ask for inclusion that late in the cycle are: 1) The code causes lockdep splats vs. hotplug locking which get reported over and over. Unfortunately there is no easy fix. 2) The risk of breakage is minimal because it's already broken 3) As 4.14 is a long term stable kernel, I prefer to have working watchdog code in that and the lockdep issues resolved. I wouldn't ask you to pull if 4.14 wouldn't be a LTS kernel or if the solution would be easy to backport. 4) The series was around before the merge window opened, but then got delayed due to the UP failure caused by the for_each_cpu() surprise which we discussed recently. Changes vs. V1: - Addressed your review points - Addressed the warning in the powerpc code which was discovered late - Changed two function names which made sense up to a certain point in the series. Now they match what they do in the end. - Fixed a 'unused variable' warning, which got not detected by the intel robot. I triggered it when trying all possible related config combinations manually. Randconfig testing seems not random enough. The changes have been tested by and reviewed by Don Zickus and tested and acked by Micheal Ellerman for powerpc" * 'core-watchdog-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) watchdog/core: Put softlockup_threads_initialized under ifdef guard watchdog/core: Rename some softlockup_* functions powerpc/watchdog: Make use of watchdog_nmi_probe() watchdog/core, powerpc: Lock cpus across reconfiguration watchdog/core, powerpc: Replace watchdog_nmi_reconfigure() watchdog/hardlockup/perf: Fix spelling mistake: "permanetely" -> "permanently" watchdog/hardlockup/perf: Cure UP damage watchdog/hardlockup: Clean up hotplug locking mess watchdog/hardlockup/perf: Simplify deferred event destroy watchdog/hardlockup/perf: Use new perf CPU enable mechanism watchdog/hardlockup/perf: Implement CPU enable replacement watchdog/hardlockup/perf: Implement init time detection of perf watchdog/hardlockup/perf: Implement init time perf validation watchdog/core: Get rid of the racy update loop watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage watchdog/sysctl: Clean up sysctl variable name space watchdog/sysctl: Get rid of the #ifdeffery watchdog/core: Clean up header mess watchdog/core: Further simplify sysctl handling watchdog/core: Get rid of the thread teardown/setup dance ...
Diffstat (limited to 'arch')
3 files changed, 20 insertions, 23 deletions
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index a45a67d526f8..30f92391a93e 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -146,7 +146,7 @@ void machine_power_off(void)
/* prevent soft lockup/stalled CPU messages for endless loop. */
- lockup_detector_suspend();
+ lockup_detector_soft_poweroff();
for (;;);
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index 2f6eadd9408d..c702a8981452 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c
@@ -310,9 +310,6 @@ static int start_wd_on_cpu(unsigned int cpu)
if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
return 0;
- if (watchdog_suspended)
- return 0;
if (!cpumask_test_cpu(cpu, &watchdog_cpumask))
return 0;
@@ -358,36 +355,39 @@ static void watchdog_calc_timeouts(void)
wd_timer_period_ms = watchdog_thresh * 1000 * 2 / 5;
-void watchdog_nmi_reconfigure(void)
+void watchdog_nmi_stop(void)
int cpu;
- watchdog_calc_timeouts();
for_each_cpu(cpu, &wd_cpus_enabled)
+void watchdog_nmi_start(void)
+ int cpu;
+ watchdog_calc_timeouts();
for_each_cpu_and(cpu, cpu_online_mask, &watchdog_cpumask)
- * This runs after lockup_detector_init() which sets up watchdog_cpumask.
+ * Invoked from core watchdog init.
-static int __init powerpc_watchdog_init(void)
+int __init watchdog_nmi_probe(void)
int err;
- watchdog_calc_timeouts();
- err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powerpc/watchdog:online",
- start_wd_on_cpu, stop_wd_on_cpu);
- if (err < 0)
+ err = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+ "powerpc/watchdog:online",
+ start_wd_on_cpu, stop_wd_on_cpu);
+ if (err < 0) {
pr_warn("Watchdog could not be initialized");
+ return err;
+ }
return 0;
static void handle_backtrace_ipi(struct pt_regs *regs)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 829e89cfcee2..9fb9a1f1e47b 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4409,10 +4409,9 @@ static __init int fixup_ht_bug(void)
return 0;
- if (lockup_detector_suspend() != 0) {
- pr_debug("failed to disable PMU erratum BJ122, BV98, HSD29 workaround\n");
- return 0;
- }
+ cpus_read_lock();
+ hardlockup_detector_perf_stop();
x86_pmu.flags &= ~(PMU_FL_EXCL_CNTRS | PMU_FL_EXCL_ENABLED);
@@ -4420,9 +4419,7 @@ static __init int fixup_ht_bug(void)
x86_pmu.commit_scheduling = NULL;
x86_pmu.stop_scheduling = NULL;
- lockup_detector_resume();
- cpus_read_lock();
+ hardlockup_detector_perf_restart();