Messages in this thread Patch in this message | | | Date | Thu, 14 Sep 2017 03:40:23 -0700 | From | tip-bot for Peter Zijlstra <> | Subject | [tip:core/urgent] perf/x86/intel, watchdog/core: Sanitize PMU HT bug workaround |
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Commit-ID: 2406e3b166eee42777a6b0b38f52f924454474d7 Gitweb: http://git.kernel.org/tip/2406e3b166eee42777a6b0b38f52f924454474d7 Author: Peter Zijlstra <peterz@infradead.org> AuthorDate: Tue, 12 Sep 2017 21:36:56 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Thu, 14 Sep 2017 11:41:03 +0200
perf/x86/intel, watchdog/core: Sanitize PMU HT bug workaround
The lockup_detector_suspend/resume() interface is broken in several ways especially as it results in recursive locking of the CPU hotplug lock.
Use the new stop/restart interface in the perf NMI watchdog to temporarily disable and reenable the already active watchdog events. That's enough to handle it.
Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Don Zickus <dzickus@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Link: http://lkml.kernel.org/r/20170912194146.247141871@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/events/intel/core.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 829e89c..9fb9a1f 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(); for_each_online_cpu(c) free_excl_cntrs(c);
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