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| author | Steven Rostedt <srostedt@redhat.com> | 2012-02-07 09:32:43 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2012-02-13 08:23:21 -0500 |
| commit | 2fbb90db1b8fcc78f43830f1a009f3af243c5f42 (patch) | |
| tree | a190e127ab6bd352d95a4a0964f0f1e8858cb2f4 /include/linux/tracepoint.h | |
| parent | f069686e4bdc60a637d210ea3eea25fcdb82df88 (diff) | |
| download | lwn-2fbb90db1b8fcc78f43830f1a009f3af243c5f42.tar.gz lwn-2fbb90db1b8fcc78f43830f1a009f3af243c5f42.zip | |
tracing/rcu: Add trace_##name##__rcuidle() static tracepoint for inside rcu_idle_exit() sections
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 <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/linux/tracepoint.h')
| -rw-r--r-- | include/linux/tracepoint.h | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index df0a779c1bbd..fc36da97ff7e 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) \ @@ -190,9 +202,11 @@ 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 void trace_##name##_rcuidle(proto) \ + { } \ static inline int \ register_trace_##name(void (*probe)(data_proto), \ void *data) \ |