Commit 2406e3b1 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar

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: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarDon 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.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent d0b6e0a8
......@@ -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);
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment