perf: Add context field to perf_event
The perf_event overflow handler does not receive any caller-derived
argument, so many callers need to resort to looking up the perf_event
in their local data structure. This is ugly and doesn't scale if a
single callback services many perf_events.
Fix by adding a context parameter to perf_event_create_kernel_counter()
(and derived hardware breakpoints APIs) and storing it in the perf_event.
The field can be accessed from the callback as event->overflow_handler_context.
All callers are updated.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 086adf2..b7971d6 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -431,9 +431,11 @@
struct perf_event *
register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered,
+ void *context,
struct task_struct *tsk)
{
- return perf_event_create_kernel_counter(attr, -1, tsk, triggered);
+ return perf_event_create_kernel_counter(attr, -1, tsk, triggered,
+ context);
}
EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
@@ -502,7 +504,8 @@
*/
struct perf_event * __percpu *
register_wide_hw_breakpoint(struct perf_event_attr *attr,
- perf_overflow_handler_t triggered)
+ perf_overflow_handler_t triggered,
+ void *context)
{
struct perf_event * __percpu *cpu_events, **pevent, *bp;
long err;
@@ -515,7 +518,8 @@
get_online_cpus();
for_each_online_cpu(cpu) {
pevent = per_cpu_ptr(cpu_events, cpu);
- bp = perf_event_create_kernel_counter(attr, cpu, NULL, triggered);
+ bp = perf_event_create_kernel_counter(attr, cpu, NULL,
+ triggered, context);
*pevent = bp;