From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755907Ab2BGPLf (ORCPT ); Tue, 7 Feb 2012 10:11:35 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:63574 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754407Ab2BGPKu (ORCPT ); Tue, 7 Feb 2012 10:10:50 -0500 X-Authority-Analysis: v=2.0 cv=HeuWv148 c=1 sm=0 a=ZycB6UtQUfgMyuk2+PxD7w==:17 a=UBy9sU4F98IA:10 a=SEpPaoqGAvwA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=20KFwNOVAAAA:8 a=VwQbUJbxAAAA:8 a=ayC55rCoAAAA:8 a=VnNF1IyMAAAA:8 a=UPm3pfgAAAAA:8 a=meVymXHHAAAA:8 a=wv91tmdJEZCA7l7znooA:9 a=_Pu3XhDJXVXLl6GBpEQA:7 a=jEp0ucaQiEUA:10 a=mOio7EKfaG4A:10 a=jeBq3FmKZ4MA:10 a=ZycB6UtQUfgMyuk2+PxD7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.80.29 Message-Id: <20120207151049.164032464@goodmis.org> User-Agent: quilt/0.50-1 Date: Tue, 07 Feb 2012 09:56:54 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , "Paul E. McKenney" , Rob Herring , Nicolas Pitre , Kevin Hilman , Josh Triplett , Mathieu Desnoyers Subject: [PATCH 1/3][RFC] tracing/rcu: Add trace_##name##__rcuidle() static tracepoint for inside rcu_idle_exit() sections References: <20120207145653.829892056@goodmis.org> Content-Disposition: inline; filename=0001-tracing-rcu-Add-trace_-name-__rcuidle-static-tracepo.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt Added is a new static inline function that lets *any* tracepoint be used inside a rcu_idle_exit() section. And this also solves the problem where the same tracepoint may be used inside a rcu_idle_exit() section as well as outside of one. I added a new tracepoint function with a "_rcuidle" extension. All tracepoints can be used with either the normal "trace_foobar()" function, or the "trace_foobar_rcuidle()" function when inside a rcu_idle_exit() section. All tracepoints defined by TRACE_EVENT() or any of the derivatives will have a "_rcuidle()" function also defined. When a tracepoint is used within an rcu_idle_exit() section, the "_rcuidle()" version must be used. This denotes that the tracepoint is within rcu_idle_exit() and it allows the rcu read locks within the tracepoint to still be valid, as this version takes us out of rcu_idle_exit(). Another nice aspect about this patch is that "static inline"s are not compiled into text when not used. So only the tracepoints that actually use the _rcuidle() version will have them defined in the actual text that is booted. Link: http://lkml.kernel.org/r/1328563113.2200.39.camel@gandalf.stny.rr.com> Acked-by: Paul E. McKenney Reviewed-by: Josh Triplett Signed-off-by: Steven Rostedt --- include/linux/tracepoint.h | 20 ++++++++++++++++---- 1 files changed, 16 insertions(+), 4 deletions(-) diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index df0a779..00d073a 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -114,7 +114,7 @@ static inline void tracepoint_synchronize_unregister(void) * as "(void *, void)". The DECLARE_TRACE_NOARGS() will pass in just * "void *data", where as the DECLARE_TRACE() will pass in "void *data, proto". */ -#define __DO_TRACE(tp, proto, args, cond) \ +#define __DO_TRACE(tp, proto, args, cond, prercu, postrcu) \ do { \ struct tracepoint_func *it_func_ptr; \ void *it_func; \ @@ -122,6 +122,7 @@ static inline void tracepoint_synchronize_unregister(void) \ if (!(cond)) \ return; \ + prercu; \ rcu_read_lock_sched_notrace(); \ it_func_ptr = rcu_dereference_sched((tp)->funcs); \ if (it_func_ptr) { \ @@ -132,6 +133,7 @@ static inline void tracepoint_synchronize_unregister(void) } while ((++it_func_ptr)->func); \ } \ rcu_read_unlock_sched_notrace(); \ + postrcu; \ } while (0) /* @@ -139,7 +141,7 @@ static inline void tracepoint_synchronize_unregister(void) * not add unwanted padding between the beginning of the section and the * structure. Force alignment to the same alignment as the section start. */ -#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ +#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ extern struct tracepoint __tracepoint_##name; \ static inline void trace_##name(proto) \ { \ @@ -147,7 +149,17 @@ static inline void tracepoint_synchronize_unregister(void) __DO_TRACE(&__tracepoint_##name, \ TP_PROTO(data_proto), \ TP_ARGS(data_args), \ - TP_CONDITION(cond)); \ + TP_CONDITION(cond),,); \ + } \ + static inline void trace_##name##_rcuidle(proto) \ + { \ + if (static_branch(&__tracepoint_##name.key)) \ + __DO_TRACE(&__tracepoint_##name, \ + TP_PROTO(data_proto), \ + TP_ARGS(data_args), \ + TP_CONDITION(cond), \ + rcu_idle_exit(), \ + rcu_idle_enter()); \ } \ static inline int \ register_trace_##name(void (*probe)(data_proto), void *data) \ @@ -190,7 +202,7 @@ static inline void tracepoint_synchronize_unregister(void) EXPORT_SYMBOL(__tracepoint_##name) #else /* !CONFIG_TRACEPOINTS */ -#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ +#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ static inline void trace_##name(proto) \ { } \ static inline int \ -- 1.7.8.3