From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: [RFC PATCH 1/3] Tracepoint: fix documentation of RCU lockdep checks Date: Wed, 7 Oct 2015 06:39:18 -0400 Message-ID: <1444214360-16708-1-git-send-email-mathieu.desnoyers@efficios.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, lttng-dev@lists.lttng.org, Mathieu Desnoyers , Dave Hansen List-Id: lttng-dev@lists.lttng.org 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. Fixes: a05d59a56733 "tracing: Add condition check to RCU lockdep checks" Signed-off-by: Mathieu Desnoyers CC: Dave Hansen CC: Steven Rostedt --- 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 a5f7f3e..c8e3030 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -167,10 +167,11 @@ 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; \ -- 2.1.4