Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e12cbc10 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Ingo Molnar
Browse files

hw_breakpoint: Simplify *register_wide_hw_breakpoint() 



1. register_wide_hw_breakpoint() can use unregister_ if failure,
   no need to duplicate the code.

2. "struct perf_event **pevent" adds the unnecesary lever of
   indirection and complication, use per_cpu(*cpu_events, cpu).

Reported-by: default avatarVince Weaver <vincent.weaver@maine.edu>
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20130620155018.GA6347@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 1c10adbb

kernel/events/hw_breakpoint.c

+11 −23
Original line number Diff line number Diff line
@@ -497,8 +497,8 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, 
			    perf_overflow_handler_t triggered,

			    void *context)

{

	struct perf_event * __percpu *cpu_events, **pevent, *bp;

	long err;

	struct perf_event * __percpu *cpu_events, *bp;

	long err = 0;

	int cpu;



	cpu_events = alloc_percpu(typeof(*cpu_events));
@@ -507,31 +507,21 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, 


	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, context);



		*pevent = bp;



		if (IS_ERR(bp)) {

			err = PTR_ERR(bp);

			goto fail;

			break;

		}



		per_cpu(*cpu_events, cpu) = bp;

	}

	put_online_cpus();



	if (likely(!err))

		return cpu_events;



fail:

	for_each_online_cpu(cpu) {

		pevent = per_cpu_ptr(cpu_events, cpu);

		if (IS_ERR(*pevent))

			break;

		unregister_hw_breakpoint(*pevent);

	}

	put_online_cpus();



	free_percpu(cpu_events);

	unregister_wide_hw_breakpoint(cpu_events);

	return (void __percpu __force *)ERR_PTR(err);

}

EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint);
@@ -543,12 +533,10 @@ EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint); 
void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)

{

	int cpu;

	struct perf_event **pevent;



	for_each_possible_cpu(cpu) {

		pevent = per_cpu_ptr(cpu_events, cpu);

		unregister_hw_breakpoint(*pevent);

	}

	for_each_possible_cpu(cpu)

		unregister_hw_breakpoint(per_cpu(*cpu_events, cpu));



	free_percpu(cpu_events);

}

EXPORT_SYMBOL_GPL(unregister_wide_hw_breakpoint);