Commit-ID: 2406e3b166eee42777a6b0b38f52f924454474d7 Gitweb: http://git.kernel.org/tip/2406e3b166eee42777a6b0b38f52f924454474d7 Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Tue, 12 Sep 2017 21:36:56 +0200 Committer: Ingo Molnar <mi...@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 <pet...@infradead.org> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Don Zickus <dzic...@redhat.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Borislav Petkov <b...@alien8.de> Cc: Chris Metcalf <cmetc...@mellanox.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Nicholas Piggin <npig...@gmail.com> Cc: Sebastian Siewior <bige...@linutronix.de> Cc: Ulrich Obergfell <uober...@redhat.com> Link: http://lkml.kernel.org/r/20170912194146.247141...@linutronix.de Signed-off-by: Ingo Molnar <mi...@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);
