| From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 154/164] tracepoints: Fix documentation of RCU lockdep checks | Date | Wed, 2 Dec 2015 09:00:05 -0800 |
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3.19.8-ckt11 -stable review patch. If anyone has any objections, please let me know.
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From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
commit a15920bea0428cd22291637f6c72542b1843e65f upstream.
The documentation on top of __DECLARE_TRACE() does not match its implementation since the condition check has been added to the RCU lockdep checks. Update the documentation to match its implementation.
Link: http://lkml.kernel.org/r/1446504164-21563-1-git-send-email-mathieu.desnoyers@efficios.com
CC: Dave Hansen <dave@sr71.net> Fixes: a05d59a56733 "tracing: Add condition check to RCU lockdep checks" Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- include/linux/tracepoint.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index c728513..37917e4 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -159,10 +159,11 @@ extern void syscall_unregfunc(void); * structure. Force alignment to the same alignment as the section start. * * When lockdep is enabled, we make sure to always do the RCU portions of - * the tracepoint code, regardless of whether tracing is on or we match the - * condition. This lets us find RCU issues triggered with tracepoints even - * when this tracepoint is off. This code has no purpose other than poking - * RCU a bit. + * the tracepoint code, regardless of whether tracing is on. However, + * don't check if the condition is false, due to interaction with idle + * instrumentation. This lets us find RCU issues triggered with tracepoints + * even when this tracepoint is off. This code has no purpose other than + * poking RCU a bit. */ #define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ extern struct tracepoint __tracepoint_##name; \ -- 1.9.1
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