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: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20130620155018.GA6347@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Oleg Nesterov 2013-06-20 17:50:18 +02:00 committed by Ingo Molnar
parent 1c10adbb92
commit e12cbc10cb

View file

@ -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;
}
}
put_online_cpus();
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);
}
per_cpu(*cpu_events, cpu) = bp;
}
put_online_cpus();
free_percpu(cpu_events);
if (likely(!err))
return 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);