Commit 654ced4a authored by Mathieu Desnoyers's avatar Mathieu Desnoyers Committed by Steven Rostedt (Google)
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tracing: Introduce tracepoint_is_faultable() 



Introduce a "faultable" flag within the extended structure to know
whether a tracepoint needs rcu tasks trace grace period before reclaim.
This can be queried using tracepoint_is_faultable().

Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Tested-by: default avatarJordan Rife <jrife@google.com>
Cc: Michael Jeanson <mjeanson@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: bpf@vger.kernel.org
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Jordan Rife <jrife@google.com>
Cc: linux-trace-kernel@vger.kernel.org
Link: https://lore.kernel.org/20241031152056.744137-3-mathieu.desnoyers@efficios.com


Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent a9cfb877

include/linux/tracepoint-defs.h

+2 −0
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ struct tracepoint_func { 
struct tracepoint_ext {

	int (*regfunc)(void);

	void (*unregfunc)(void);

	/* Flags. */

	unsigned int faultable:1;

};



struct tracepoint {

include/linux/tracepoint.h

+24 −0
Original line number Diff line number Diff line
@@ -104,6 +104,12 @@ void for_each_tracepoint_in_module(struct module *mod, 
 * tracepoint_synchronize_unregister must be called between the last tracepoint

 * probe unregistration and the end of module exit to make sure there is no

 * caller executing a probe when it is freed.

 *

 * An alternative is to use the following for batch reclaim associated

 * with a given tracepoint:

 *

 * - tracepoint_is_faultable() == false: call_rcu()

 * - tracepoint_is_faultable() == true:  call_rcu_tasks_trace()

 */

#ifdef CONFIG_TRACEPOINTS

static inline void tracepoint_synchronize_unregister(void)
@@ -111,9 +117,17 @@ static inline void tracepoint_synchronize_unregister(void) 
	synchronize_rcu_tasks_trace();

	synchronize_rcu();

}

static inline bool tracepoint_is_faultable(struct tracepoint *tp)

{

	return tp->ext && tp->ext->faultable;

}

#else

static inline void tracepoint_synchronize_unregister(void)

{ }

static inline bool tracepoint_is_faultable(struct tracepoint *tp)

{

	return false;

}

#endif



#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
@@ -345,6 +359,15 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
	static struct tracepoint_ext __tracepoint_ext_##_name = {	\

		.regfunc = _reg,					\

		.unregfunc = _unreg,					\

		.faultable = false,					\

	};								\

	__DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARAMS(_args));



#define DEFINE_TRACE_SYSCALL(_name, _reg, _unreg, _proto, _args)	\

	static struct tracepoint_ext __tracepoint_ext_##_name = {	\

		.regfunc = _reg,					\

		.unregfunc = _unreg,					\

		.faultable = true,					\

	};								\

	__DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARAMS(_args));
@@ -389,6 +412,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
#define __DECLARE_TRACE_SYSCALL	__DECLARE_TRACE



#define DEFINE_TRACE_FN(name, reg, unreg, proto, args)

#define DEFINE_TRACE_SYSCALL(name, reg, unreg, proto, args)

#define DEFINE_TRACE(name, proto, args)

#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)

#define EXPORT_TRACEPOINT_SYMBOL(name)

include/trace/define_trace.h

+1 −1
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ 


#undef TRACE_EVENT_SYSCALL

#define TRACE_EVENT_SYSCALL(name, proto, args, struct, assign, print, reg, unreg) \

	DEFINE_TRACE_FN(name, reg, unreg, PARAMS(proto), PARAMS(args))

	DEFINE_TRACE_SYSCALL(name, reg, unreg, PARAMS(proto), PARAMS(args))



#undef TRACE_EVENT_NOP

#define TRACE_EVENT_NOP(name, proto, args, struct, assign, print)