From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753115Ab3HVOOn (ORCPT ); Thu, 22 Aug 2013 10:14:43 -0400 Received: from mail-bk0-f51.google.com ([209.85.214.51]:45951 "EHLO mail-bk0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752331Ab3HVOOj (ORCPT ); Thu, 22 Aug 2013 10:14:39 -0400 From: Robert Richter To: Peter Zijlstra Cc: Ingo Molnar , Arnaldo Carvalho de Melo , Borislav Petkov , Jiri Olsa , linux-kernel@vger.kernel.org, Robert Richter , Robert Richter Subject: [PATCH v3 02/12] perf, mmap: Factor out try_get_event()/put_event() Date: Thu, 22 Aug 2013 16:13:17 +0200 Message-Id: <1377180807-12758-3-git-send-email-rric@kernel.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1377180807-12758-1-git-send-email-rric@kernel.org> References: <1377180807-12758-1-git-send-email-rric@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Robert Richter 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 Signed-off-by: Robert Richter --- 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 5dcc5fe..c9a5d4c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3242,13 +3242,10 @@ 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); /* @@ -3781,7 +3778,7 @@ 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. @@ -7445,7 +7442,7 @@ 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 ca65997..96a07d2 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -178,4 +178,16 @@ 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 */ -- 1.8.3.2