perf: Remove fragile swevent hlist optimization

Currently we only allocate a single cpu hashtable for per-cpu
swevents; do away with this optimization for it is fragile in the face
of things like perf_pmu_migrate_context().

The easiest thing is to make sure all CPUs are consistent wrt state.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130913111447.GN31370@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d724e77..72348dc 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5680,11 +5680,6 @@ static void swevent_hlist_put(struct perf_event *event)
 {
        int cpu;
 
-       if (event->cpu != -1) {
-               swevent_hlist_put_cpu(event, event->cpu);
-               return;
-       }
-
        for_each_possible_cpu(cpu)
                swevent_hlist_put_cpu(event, cpu);
 }
@@ -5718,9 +5713,6 @@ static int swevent_hlist_get(struct perf_event *event)
        int err;
        int cpu, failed_cpu;
 
-       if (event->cpu != -1)
-               return swevent_hlist_get_cpu(event, event->cpu);
-
        get_online_cpus();
        for_each_possible_cpu(cpu) {
                err = swevent_hlist_get_cpu(event, cpu);