Return-path: Received: from mga09.intel.com ([134.134.136.24]) by bombadil.infradead.org with esmtp (Exim 4.68 #1 (Red Hat Linux)) id 1KSkLJ-0000an-TR for kexec@lists.infradead.org; Tue, 12 Aug 2008 03:14:42 +0000 Subject: [PATCH -v3 6/7] kexec jump: __ftrace_enabled_save/restore From: Huang Ying Date: Tue, 12 Aug 2008 11:14:36 +0800 Message-Id: <1218510876.24951.45.camel@caritas-dev.intel.com> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Steven Rostedt , "Eric W. Biederman" , Pavel Machek , nigel@nigel.suspend2.net, "Rafael J. Wysocki" , Andrew Morton , Vivek Goyal , mingo@elte.hu, Linus Torvalds Cc: Kexec Mailing List , linux-kernel@vger.kernel.org Add __ftrace_enabled_save/restore, used to disable ftrace for a while. Now, this is used by kexec jump, which need a version without lock, for general situation, a locked version should be used. Signed-off-by: Huang Ying --- include/linux/ftrace.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -98,6 +98,27 @@ static inline void tracer_disable(void) #endif } +/* Ftrace disable/restore without lock. Some synchronization mechanism + * must be used to prevent ftrace_enabled to be changed between + * disable/restore. */ +static inline int __ftrace_enabled_save(void) +{ +#ifdef CONFIG_FTRACE + int saved_ftrace_enabled = ftrace_enabled; + ftrace_enabled = 0; + return saved_ftrace_enabled; +#else + return 0; +#endif +} + +static inline void __ftrace_enabled_restore(int enabled) +{ +#ifdef CONFIG_FTRACE + ftrace_enabled = enabled; +#endif +} + #ifdef CONFIG_FRAME_POINTER /* TODO: need to fix this for ARM */ # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0)) _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec