Messages in this thread Patch in this message | | | From | Jean Pihet <> | Subject | [PATCH 02/16] perf, mmap: Factor out try_get_event()/put_event() | Date | Mon, 7 Apr 2014 17:04:24 +0200 |
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From: Robert Richter <robert.richter@linaro.org>
Implement try_get_event() as counter part to put_event(). Put both in internal.h to make it available to other perf files.
Signed-off-by: Robert Richter <robert.richter@linaro.org> Signed-off-by: Robert Richter <rric@kernel.org> Signed-off-by: Jean Pihet <jean.pihet@linaro.org> --- kernel/events/core.c | 9 +++------ kernel/events/internal.h | 12 ++++++++++++ 2 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c index 8867236..5eaba42 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3311,13 +3311,10 @@ EXPORT_SYMBOL_GPL(perf_event_release_kernel); /* * Called when the last reference to the file is gone. */ -static void put_event(struct perf_event *event) +void __put_event(struct perf_event *event) { struct task_struct *owner; - if (!atomic_long_dec_and_test(&event->refcount)) - return; - rcu_read_lock(); owner = ACCESS_ONCE(event->owner); /* @@ -3884,7 +3881,7 @@ static void ring_buffer_detach_all(struct ring_buffer *rb) again: rcu_read_lock(); list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { - if (!atomic_long_inc_not_zero(&event->refcount)) { + if (!try_get_event(event)) { /* * This event is en-route to free_event() which will * detach it and remove it from the list. @@ -7606,7 +7603,7 @@ inherit_event(struct perf_event *parent_event, if (IS_ERR(child_event)) return child_event; - if (!atomic_long_inc_not_zero(&parent_event->refcount)) { + if (!try_get_event(parent_event)) { free_event(child_event); return NULL; } diff --git a/kernel/events/internal.h b/kernel/events/internal.h index 569b2187..3bd89d4 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -195,4 +195,16 @@ static inline bool arch_perf_have_user_stack_dump(void) #define perf_user_stack_pointer(regs) 0 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */ +static inline bool try_get_event(struct perf_event *event) +{ + return atomic_long_inc_not_zero(&event->refcount) != 0; +} +extern void __put_event(struct perf_event *event); +static inline void put_event(struct perf_event *event) +{ + if (!atomic_long_dec_and_test(&event->refcount)) + return; + __put_event(event); +} + #endif /* _KERNEL_EVENTS_INTERNAL_H */ -- 1.7.11.7
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