diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2016-02-09 20:11:26 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-17 10:37:29 +0100 |
| commit | 27ca9236c96f4a21b72a2b4f08260efeab951bd0 (patch) | |
| tree | e0409b083e3709c1b6e735704df145fb4c14e3f1 | |
| parent | b4f75d44bed1bdbb14ac704bfc38f62a3675e591 (diff) | |
perf/core: Remove the bogus and dangerous CPU_DOWN_FAILED hotplug state
If CPU_DOWN_PREPARE fails the perf hotplug notifier is called for
CPU_DOWN_FAILED and calls perf_event_init_cpu(), which checks whether the
swhash is referenced. If yes it allocates a new hash and stores the pointer in
the per cpu data structure.
But at this point the cpu is still online, so there must be a valid hash
already. By overwriting the pointer the existing hash is not longer
accessible.
Remove the CPU_DOWN_FAILED state, as there is nothing to (re)allocate.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20160209201007.763417379@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | kernel/events/core.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 474ffeafe363..4aa64a85a7b7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9282,7 +9282,6 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) switch (action & ~CPU_TASKS_FROZEN) { case CPU_UP_PREPARE: - case CPU_DOWN_FAILED: perf_event_init_cpu(cpu); break; |