Commit 5abb6ccb authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt (Google)
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tracing: Have function graph tracer option sleep-time be per instance 

Currently the option to have function graph tracer to ignore time spent
when a task is sleeping is global when the interface is per-instance.
Changing the value in one instance will affect the results of another
instance that is also running the function graph tracer. This can lead to
confusing results.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20251114192318.950255167@kernel.org


Fixes: c132be2c ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 4132886e

kernel/trace/fgraph.c

+1 −9
Original line number Diff line number Diff line
@@ -498,9 +498,6 @@ void *fgraph_retrieve_parent_data(int idx, int *size_bytes, int depth) 
	return get_data_type_data(current, offset);

}



/* Both enabled by default (can be cleared by function_graph tracer flags */

bool fgraph_sleep_time = true;



#ifdef CONFIG_DYNAMIC_FTRACE

/*

 * archs can override this function if they must do something
@@ -1023,11 +1020,6 @@ void fgraph_init_ops(struct ftrace_ops *dst_ops, 
#endif

}



void ftrace_graph_sleep_time_control(bool enable)

{

	fgraph_sleep_time = enable;

}



/*

 * Simply points to ftrace_stub, but with the proper protocol.

 * Defined by the linker script in linux/vmlinux.lds.h
@@ -1098,7 +1090,7 @@ ftrace_graph_probe_sched_switch(void *ignore, bool preempt, 
	 * Does the user want to count the time a function was asleep.

	 * If so, do not update the time stamps.

	 */

	if (fgraph_sleep_time)

	if (!fgraph_no_sleep_time)

		return;



	timestamp = trace_clock_local();

kernel/trace/ftrace.c

+3 −1
Original line number Diff line number Diff line
@@ -862,6 +862,8 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace, 
	return 1;

}



bool fprofile_no_sleep_time;



static void profile_graph_return(struct ftrace_graph_ret *trace,

				 struct fgraph_ops *gops,

				 struct ftrace_regs *fregs)
@@ -887,7 +889,7 @@ static void profile_graph_return(struct ftrace_graph_ret *trace, 


	calltime = rettime - profile_data->calltime;



	if (!fgraph_sleep_time) {

	if (fprofile_no_sleep_time) {

		if (current->ftrace_sleeptime)

			calltime -= current->ftrace_sleeptime - profile_data->sleeptime;

	}

kernel/trace/trace.h

+2 −3
Original line number Diff line number Diff line
@@ -943,8 +943,6 @@ static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash) 
#define TRACE_GRAPH_PRINT_FILL_SHIFT	28

#define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)



extern void ftrace_graph_sleep_time_control(bool enable);



#ifdef CONFIG_FUNCTION_PROFILER

extern void ftrace_graph_graph_time_control(bool enable);

#else
@@ -1115,7 +1113,8 @@ static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftra 
#endif /* CONFIG_DYNAMIC_FTRACE */



extern unsigned int fgraph_max_depth;

extern bool fgraph_sleep_time;

extern unsigned int fgraph_no_sleep_time;

extern bool fprofile_no_sleep_time;



static inline bool

ftrace_graph_ignore_func(struct fgraph_ops *gops, struct ftrace_graph_ent *trace)

kernel/trace/trace_functions_graph.c

+54 −10
Original line number Diff line number Diff line
@@ -19,6 +19,9 @@ 
/* When set, irq functions might be ignored */

static int ftrace_graph_skip_irqs;



/* Do not record function time when task is sleeping */

unsigned int fgraph_no_sleep_time;



struct fgraph_cpu_data {

	pid_t		last_pid;

	int		depth;
@@ -239,13 +242,14 @@ static int graph_entry(struct ftrace_graph_ent *trace, 
	if (ftrace_graph_ignore_irqs(tr))

		return 0;



	if (fgraph_sleep_time) {

		/* Only need to record the calltime */

		ftimes = fgraph_reserve_data(gops->idx, sizeof(ftimes->calltime));

	} else {

	if (fgraph_no_sleep_time &&

	    !tracer_flags_is_set(tr, TRACE_GRAPH_SLEEP_TIME)) {

		ftimes = fgraph_reserve_data(gops->idx, sizeof(*ftimes));

		if (ftimes)

			ftimes->sleeptime = current->ftrace_sleeptime;

	} else {

		/* Only need to record the calltime */

		ftimes = fgraph_reserve_data(gops->idx, sizeof(ftimes->calltime));

	}

	if (!ftimes)

		return 0;
@@ -331,11 +335,15 @@ void __trace_graph_return(struct trace_array *tr, 
	trace_buffer_unlock_commit_nostack(buffer, event);

}



static void handle_nosleeptime(struct ftrace_graph_ret *trace,

static void handle_nosleeptime(struct trace_array *tr,

			       struct ftrace_graph_ret *trace,

			       struct fgraph_times *ftimes,

			       int size)

{

	if (fgraph_sleep_time || size < sizeof(*ftimes))

	if (size < sizeof(*ftimes))

		return;



	if (!fgraph_no_sleep_time || tracer_flags_is_set(tr, TRACE_GRAPH_SLEEP_TIME))

		return;



	ftimes->calltime += current->ftrace_sleeptime - ftimes->sleeptime;
@@ -364,7 +372,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace, 
	if (!ftimes)

		return;



	handle_nosleeptime(trace, ftimes, size);

	handle_nosleeptime(tr, trace, ftimes, size);



	calltime = ftimes->calltime;
@@ -377,6 +385,7 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, 
				      struct ftrace_regs *fregs)

{

	struct fgraph_times *ftimes;

	struct trace_array *tr;

	int size;



	ftrace_graph_addr_finish(gops, trace);
@@ -390,7 +399,8 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, 
	if (!ftimes)

		return;



	handle_nosleeptime(trace, ftimes, size);

	tr = gops->private;

	handle_nosleeptime(tr, trace, ftimes, size);



	if (tracing_thresh &&

	    (trace_clock_local() - ftimes->calltime < tracing_thresh))
@@ -452,6 +462,9 @@ static int graph_trace_init(struct trace_array *tr) 
	if (!tracer_flags_is_set(tr, TRACE_GRAPH_PRINT_IRQS))

		ftrace_graph_skip_irqs++;



	if (!tracer_flags_is_set(tr, TRACE_GRAPH_SLEEP_TIME))

		fgraph_no_sleep_time++;



	/* Make gops functions visible before we start tracing */

	smp_mb();
@@ -494,6 +507,11 @@ static void graph_trace_reset(struct trace_array *tr) 
	if (WARN_ON_ONCE(ftrace_graph_skip_irqs < 0))

		ftrace_graph_skip_irqs = 0;



	if (!tracer_flags_is_set(tr, TRACE_GRAPH_SLEEP_TIME))

		fgraph_no_sleep_time--;

	if (WARN_ON_ONCE(fgraph_no_sleep_time < 0))

		fgraph_no_sleep_time = 0;



	tracing_stop_cmdline_record();

	unregister_ftrace_graph(tr->gops);

}
@@ -1619,8 +1637,24 @@ void graph_trace_close(struct trace_iterator *iter) 
static int

func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)

{

	if (bit == TRACE_GRAPH_SLEEP_TIME)

		ftrace_graph_sleep_time_control(set);

/*

 * The function profiler gets updated even if function graph

 * isn't the current tracer. Handle it separately.

 */

#ifdef CONFIG_FUNCTION_PROFILER

	if (bit == TRACE_GRAPH_SLEEP_TIME && (tr->flags & TRACE_ARRAY_FL_GLOBAL) &&

	    !!set == fprofile_no_sleep_time) {

		if (set) {

			fgraph_no_sleep_time--;

			if (WARN_ON_ONCE(fgraph_no_sleep_time < 0))

				fgraph_no_sleep_time = 0;

			fprofile_no_sleep_time = false;

		} else {

			fgraph_no_sleep_time++;

			fprofile_no_sleep_time = true;

		}

	}

#endif



	/* Do nothing if the current tracer is not this tracer */

	if (tr->current_trace != &graph_trace)
@@ -1630,6 +1664,16 @@ func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) 
	if (!!set == !!(tr->current_trace_flags->val & bit))

		return 0;



	if (bit == TRACE_GRAPH_SLEEP_TIME) {

		if (set) {

			fgraph_no_sleep_time--;

			if (WARN_ON_ONCE(fgraph_no_sleep_time < 0))

				fgraph_no_sleep_time = 0;

		} else {

			fgraph_no_sleep_time++;

		}

	}



	if (bit == TRACE_GRAPH_PRINT_IRQS) {

		if (set)

			ftrace_graph_skip_irqs--;