From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org, mingo@elte.hu,
laijs@cn.fujitsu.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca,
niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org,
Valdis.Kletnieks@vt.edu, dhowells@redhat.com,
eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com,
sbw@mit.edu, patches@linaro.org,
"Paul E. McKenney" <paul.mckenney@linaro.org>
Subject: Re: [PATCH] trace: Don't declare trace_*_rcuidle functions in modules
Date: Wed, 5 Sep 2012 09:36:01 -0700 [thread overview]
Message-ID: <20120905163601.GD3308@linux.vnet.ibm.com> (raw)
In-Reply-To: <20120905062306.GA14756@leaf>
On Tue, Sep 04, 2012 at 11:23:06PM -0700, Josh Triplett wrote:
> Tracepoints declare a static inline trace_*_rcuidle variant of the trace
> function, to support safely generating trace events from the idle loop.
> Module code never actually uses that variant of trace functions, because
> modules don't run code that needs tracing with RCU idled. However, the
> declaration of those otherwise unused functions causes the module to
> reference rcu_idle_exit and rcu_idle_enter, which RCU does not export to
> modules.
>
> To avoid this, don't generate trace_*_rcuidle functions for tracepoints
> declared in module code.
>
> Reported-by: Steven Rostedt <rostedt@goodmis.org>
> Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Looks good to me, please let me know when I should remove the exports.
Sending the relevant patch is sufficient notification. ;-)
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Thanx, Paul
> ---
> On Tue, Sep 04, 2012 at 07:46:42PM -0400, Steven Rostedt wrote:
> > We could add either. Probably keep the ugliness of tracepoints inside
> > the tracepoint code than to start spreading it around to rcu. RCU has
> > its own ugliness features ;-)
> >
> > Hence, I would be OK if you send me a patch that does what you proposed
> > and removes the EXPORT from RCU.
>
> include/linux/tracepoint.h | 28 ++++++++++++++++++----------
> 1 file changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
> index 802de56..2f322c3 100644
> --- a/include/linux/tracepoint.h
> +++ b/include/linux/tracepoint.h
> @@ -136,6 +136,22 @@ static inline void tracepoint_synchronize_unregister(void)
> postrcu; \
> } while (0)
>
> +#ifndef MODULE
> +#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args) \
> + static inline void trace_##name##_rcuidle(proto) \
> + { \
> + if (static_key_false(&__tracepoint_##name.key)) \
> + __DO_TRACE(&__tracepoint_##name, \
> + TP_PROTO(data_proto), \
> + TP_ARGS(data_args), \
> + TP_CONDITION(cond), \
> + rcu_idle_exit(), \
> + rcu_idle_enter()); \
> + }
> +#else
> +#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)
> +#endif
> +
> /*
> * Make sure the alignment of the structure in the __tracepoints section will
> * not add unwanted padding between the beginning of the section and the
> @@ -151,16 +167,8 @@ static inline void tracepoint_synchronize_unregister(void)
> TP_ARGS(data_args), \
> TP_CONDITION(cond),,); \
> } \
> - static inline void trace_##name##_rcuidle(proto) \
> - { \
> - if (static_key_false(&__tracepoint_##name.key)) \
> - __DO_TRACE(&__tracepoint_##name, \
> - TP_PROTO(data_proto), \
> - TP_ARGS(data_args), \
> - TP_CONDITION(cond), \
> - rcu_idle_exit(), \
> - rcu_idle_enter()); \
> - } \
> + __DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \
> + PARAMS(cond), PARAMS(data_proto), PARAMS(data_args)) \
> static inline int \
> register_trace_##name(void (*probe)(data_proto), void *data) \
> { \
> --
> 1.7.10.4
>
next prev parent reply other threads:[~2012-09-05 16:38 UTC|newest]
Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-30 18:56 [PATCH tip/core/rcu 0/15] Miscellaneous fixes Paul E. McKenney
2012-08-30 18:56 ` [PATCH tip/core/rcu 01/15] rcu: Add PROVE_RCU_DELAY to provoke difficult races Paul E. McKenney
2012-08-30 18:56 ` [PATCH tip/core/rcu 02/15] rcu: Pull TINY_RCU dyntick-idle tracing into non-idle region Paul E. McKenney
2012-08-31 16:53 ` Josh Triplett
2012-08-30 18:56 ` [PATCH tip/core/rcu 03/15] rcu: Properly initialize ->boost_tasks on CPU offline Paul E. McKenney
2012-08-31 17:56 ` Josh Triplett
2012-09-06 14:40 ` Peter Zijlstra
2012-09-06 20:58 ` Paul E. McKenney
2012-08-30 18:56 ` [PATCH tip/core/rcu 04/15] rcu: Permit RCU_NONIDLE() to be used from interrupt context Paul E. McKenney
2012-08-31 18:00 ` Josh Triplett
2012-09-04 22:33 ` Paul E. McKenney
2012-09-04 22:48 ` Josh Triplett
2012-09-04 22:51 ` Steven Rostedt
2012-09-04 23:08 ` Josh Triplett
2012-09-04 23:23 ` Steven Rostedt
2012-09-04 23:33 ` Josh Triplett
2012-09-04 23:43 ` Paul E. McKenney
2012-09-06 18:54 ` Josh Triplett
2012-09-06 19:54 ` Steven Rostedt
2012-09-07 6:09 ` Josh Triplett
2012-09-07 14:24 ` Paul E. McKenney
2012-09-07 14:47 ` Josh Triplett
2012-09-07 15:16 ` Steven Rostedt
2012-09-12 1:07 ` Paul E. McKenney
2012-09-12 14:13 ` Steven Rostedt
2012-09-12 15:03 ` Paul E. McKenney
2012-09-12 15:18 ` Steven Rostedt
2012-09-12 16:57 ` Paul E. McKenney
2012-09-04 23:46 ` Steven Rostedt
2012-09-05 0:42 ` Josh Triplett
2012-09-05 6:23 ` [PATCH] trace: Don't declare trace_*_rcuidle functions in modules Josh Triplett
2012-09-05 14:26 ` Mathieu Desnoyers
2012-09-05 16:36 ` Paul E. McKenney [this message]
2012-09-06 19:49 ` Steven Rostedt
2012-09-14 6:07 ` [tip:core/rcu] trace: Don' t " tip-bot for Josh Triplett
2012-09-04 23:14 ` [PATCH tip/core/rcu 04/15] rcu: Permit RCU_NONIDLE() to be used from interrupt context Paul E. McKenney
2012-08-30 18:56 ` [PATCH tip/core/rcu 05/15] rcu: Improve boost selection when moving tasks to root rcu_node Paul E. McKenney
2012-08-31 18:09 ` Josh Triplett
2012-08-30 18:56 ` [PATCH tip/core/rcu 06/15] rcu: Make offline-CPU checking allow for indefinite delays Paul E. McKenney
2012-08-31 18:12 ` Josh Triplett
2012-08-30 18:56 ` [PATCH tip/core/rcu 07/15] rcu: Fix obsolete rcu_initiate_boost() header comment Paul E. McKenney
2012-08-31 18:13 ` Josh Triplett
2012-08-30 18:56 ` [PATCH tip/core/rcu 08/15] rcu: Apply for_each_rcu_flavor() to increment_cpu_stall_ticks() Paul E. McKenney
2012-08-31 18:15 ` Josh Triplett
2012-09-04 22:44 ` Paul E. McKenney
2012-08-30 18:56 ` [PATCH tip/core/rcu 09/15] rcu: Avoid rcu_print_detail_task_stall_rnp() segfault Paul E. McKenney
2012-08-31 18:19 ` Josh Triplett
2012-09-04 22:46 ` Paul E. McKenney
2012-09-04 22:55 ` Josh Triplett
2012-08-30 18:56 ` [PATCH tip/core/rcu 10/15] rcu: Protect rcu_node accesses during CPU stall warnings Paul E. McKenney
2012-08-31 18:23 ` Josh Triplett
2012-09-04 22:51 ` Paul E. McKenney
2012-09-06 14:51 ` Peter Zijlstra
2012-09-06 21:01 ` Paul E. McKenney
2012-08-30 18:56 ` [PATCH tip/core/rcu 11/15] rcu: Avoid spurious RCU " Paul E. McKenney
2012-08-31 18:24 ` Josh Triplett
2012-09-06 14:56 ` Peter Zijlstra
2012-09-06 15:07 ` Steven Rostedt
2012-09-06 15:19 ` Peter Zijlstra
2012-09-06 21:03 ` Paul E. McKenney
2012-09-06 21:41 ` Steven Rostedt
2012-09-06 21:58 ` Paul E. McKenney
2012-09-06 22:05 ` Steven Rostedt
2012-09-06 22:22 ` Paul E. McKenney
2012-09-07 7:00 ` Peter Zijlstra
2012-09-07 14:42 ` Steven Rostedt
2012-08-30 18:56 ` [PATCH tip/core/rcu 12/15] rcu: Remove redundant memory barrier from __call_rcu() Paul E. McKenney
2012-08-31 18:30 ` Josh Triplett
2012-08-31 18:40 ` Josh Triplett
2012-08-30 18:56 ` [PATCH tip/core/rcu 13/15] rcu: Move TINY_PREEMPT_RCU away from raw_local_irq_save() Paul E. McKenney
2012-08-31 18:34 ` Josh Triplett
2012-09-04 23:03 ` Paul E. McKenney
2012-08-30 18:56 ` [PATCH tip/core/rcu 14/15] time: RCU permitted to stop idle entry via softirq Paul E. McKenney
2012-08-31 18:51 ` Josh Triplett
2012-09-06 15:12 ` Peter Zijlstra
2012-09-06 21:35 ` Paul E. McKenney
2012-09-06 21:57 ` Steven Rostedt
2012-09-06 22:11 ` Paul E. McKenney
2012-08-30 18:56 ` [PATCH tip/core/rcu 15/15] kmemleak: Replace list_for_each_continue_rcu with new interface Paul E. McKenney
2012-08-31 18:55 ` Josh Triplett
2012-09-04 23:41 ` Paul E. McKenney
2012-08-31 16:49 ` [PATCH tip/core/rcu 01/15] rcu: Add PROVE_RCU_DELAY to provoke difficult races Josh Triplett
2012-09-04 22:36 ` Paul E. McKenney
2012-09-06 14:38 ` Peter Zijlstra
2012-09-06 20:51 ` Paul E. McKenney
2012-09-07 6:54 ` Peter Zijlstra
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