From: Peter Zijlstra <[email protected]> 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 <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Don Zickus <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Sebastian Siewior <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Ulrich Obergfell <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Andrew Morton <[email protected]> Link: http://lkml.kernel.org/r/[email protected] --- arch/x86/events/intel/core.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) --- 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);
