In this patchset, I introduce some new macros TRACE_EVENT_NOP,
DEFINE_EVENT_NOP and DECLARE_EVENT_CLASS_NOP, which will
define a tracepoint as do-nothing inline function.
#define DECLARE_EVENT_NOP(name, proto) \
static inline void trace_##name(proto) \
{ } \
static inline bool trace_##name##_enabled(void) \
{ \
return false; \
}
Let's take some examples for why these macros are needed.
- sched
The tracepoints trace_sched_stat_{iowait, blocked, wait, sleep} should
be not exposed to user if CONFIG_SCHEDSTATS is not set.
- rcu
When CONFIG_RCU_TRACE is not set, some rcu tracepoints are defined as
do-nothing macro without validating arguments, that is not proper.
We should validate the arguments.
Yafang Shao (3):
tracing: introduce TRACE_EVENT_NOP()
sched/fair: do not expose some tracepoints to user if
CONFIG_SCHEDSTATS is not set
rcu: validate arguments for rcu tracepoints
include/linux/tracepoint.h | 15 ++++++++
include/trace/define_trace.h | 8 +++++
include/trace/events/rcu.h | 81 ++++++++++++++------------------------------
include/trace/events/sched.h | 21 ++++++++----
kernel/rcu/rcu.h | 9 ++---
kernel/rcu/tree.c | 8 ++---
6 files changed, 68 insertions(+), 74 deletions(-)
--
1.8.3.1
