perf_counter: Fix swcounter context invariance

perf_swcounter_is_counting() uses a lock, which means we cannot
use swcounters from NMI or when holding that particular lock,
this is unintended.

The below removes the lock, this opens up race window, but not
worse than the swcounters already experience due to RCU
traversal of the context in perf_swcounter_ctx_event().

This also fixes the hard lockups while opening a lockdep
tracepoint counter.

Signed-off-by: Peter Zijlstra <[email protected]>
Acked-by: Frederic Weisbecker <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: stephane eranian <[email protected]>
Cc: Corey J Ashford <[email protected]>
LKML-Reference: <1250149915.10001.66.camel@twins>
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions