From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [RFA][PATCH 07/27] MIPS: ftrace: Add call to ftrace_graph_is_dead() in function graph code Date: Wed, 2 Jul 2014 10:31:38 -0400 Message-ID: <20140702103138.01880b1d@gandalf.local.home> References: <20140626165221.736847419@goodmis.org> <20140626165849.321719498@goodmis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140626165849.321719498@goodmis.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Thomas Gleixner , Masami Hiramatsu , "H. Peter Anvin" , linux-arch@vger.kernel.org, "Rafael J. Wysocki" , Jiri Kosina , Josh Poimboeuf , Ralf Baechle List-Id: linux-arch.vger.kernel.org Adding linux-mips@linux-mips.org. -- Steve On Thu, 26 Jun 2014 12:52:28 -0400 Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" > > ftrace_stop() is going away as it disables parts of function tracing > that affects users that should not be affected. But ftrace_graph_stop() > is built on ftrace_stop(). Here's another example of killing all of > function tracing because something went wrong with function graph > tracing. > > Instead of disabling all users of function tracing on function graph > error, disable only function graph tracing. To do this, the arch code > must call ftrace_graph_is_dead() before it implements function graph. > > Cc: Ralf Baechle > Signed-off-by: Steven Rostedt > --- > arch/mips/kernel/ftrace.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c > index 60e7e5e45af1..8b6538750fe1 100644 > --- a/arch/mips/kernel/ftrace.c > +++ b/arch/mips/kernel/ftrace.c > @@ -302,6 +302,9 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra, > &return_to_handler; > int faulted, insns; > > + if (unlikely(ftrace_graph_is_dead())) > + return; > + > if (unlikely(atomic_read(¤t->tracing_graph_pause))) > return; > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.231]:42651 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752876AbaGBObl (ORCPT ); Wed, 2 Jul 2014 10:31:41 -0400 Date: Wed, 2 Jul 2014 10:31:38 -0400 From: Steven Rostedt Subject: Re: [RFA][PATCH 07/27] MIPS: ftrace: Add call to ftrace_graph_is_dead() in function graph code Message-ID: <20140702103138.01880b1d@gandalf.local.home> In-Reply-To: <20140626165849.321719498@goodmis.org> References: <20140626165221.736847419@goodmis.org> <20140626165849.321719498@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Thomas Gleixner , Masami Hiramatsu , "H. Peter Anvin" , linux-arch@vger.kernel.org, "Rafael J. Wysocki" , Jiri Kosina , Josh Poimboeuf , Ralf Baechle Message-ID: <20140702143138.s2cGhskFoUlxyQpVAOZkkkr0Ek1A6lUj4cRrl-CZN6Y@z> Adding linux-mips@linux-mips.org. -- Steve On Thu, 26 Jun 2014 12:52:28 -0400 Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" > > ftrace_stop() is going away as it disables parts of function tracing > that affects users that should not be affected. But ftrace_graph_stop() > is built on ftrace_stop(). Here's another example of killing all of > function tracing because something went wrong with function graph > tracing. > > Instead of disabling all users of function tracing on function graph > error, disable only function graph tracing. To do this, the arch code > must call ftrace_graph_is_dead() before it implements function graph. > > Cc: Ralf Baechle > Signed-off-by: Steven Rostedt > --- > arch/mips/kernel/ftrace.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c > index 60e7e5e45af1..8b6538750fe1 100644 > --- a/arch/mips/kernel/ftrace.c > +++ b/arch/mips/kernel/ftrace.c > @@ -302,6 +302,9 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra, > &return_to_handler; > int faulted, insns; > > + if (unlikely(ftrace_graph_is_dead())) > + return; > + > if (unlikely(atomic_read(¤t->tracing_graph_pause))) > return; >