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| author | Peter Zijlstra <peterz@infradead.org> | 2017-09-12 21:36:56 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-09-14 11:41:03 +0200 |
| commit | 2406e3b166eee42777a6b0b38f52f924454474d7 (patch) | |
| tree | 955877e11ae1214cf8ed504c616457e70d671299 /arch/x86/events | |
| parent | watchdog/hardlockup: Provide interface to stop/restart perf events (diff) | |
| download | linux-2406e3b166eee42777a6b0b38f52f924454474d7.tar.xz linux-2406e3b166eee42777a6b0b38f52f924454474d7.zip | |
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>
Diffstat (limited to 'arch/x86/events')
| -rw-r--r-- | arch/x86/events/intel/core.c | 11 |
1 files changed, 4 insertions, 7 deletions
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(); for_each_online_cpu(c) free_excl_cntrs(c); |