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| author | Namhyung Kim <namhyung@kernel.org> | 2017-04-17 11:44:28 +0900 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2017-04-17 17:13:00 -0400 |
| commit | 1e10486ffee0a5b060c58b9c8c712422f7b88b3b (patch) | |
| tree | 04dd3e900cf02e26033b976602f7ca78a467b84b /kernel | |
| parent | b980b117c9ff17226937128a15692a18c9a28ed6 (diff) | |
| download | linux-1e10486ffee0a5b060c58b9c8c712422f7b88b3b.tar.gz linux-1e10486ffee0a5b060c58b9c8c712422f7b88b3b.tar.bz2 linux-1e10486ffee0a5b060c58b9c8c712422f7b88b3b.zip | |
ftrace: Add 'function-fork' trace option
The function-fork option is same as event-fork that it tracks task
fork/exit and set the pid filter properly. This can be useful if user
wants to trace selected tasks including their children only.
Link: http://lkml.kernel.org/r/20170417024430.21194-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 37 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 5 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 6 |
3 files changed, 46 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b21a3e61ac74..b5ce7ea67e02 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5600,6 +5600,43 @@ ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, trace_ignore_this_task(pid_list, next)); } +static void +ftrace_pid_follow_sched_process_fork(void *data, + struct task_struct *self, + struct task_struct *task) +{ + struct trace_pid_list *pid_list; + struct trace_array *tr = data; + + pid_list = rcu_dereference_sched(tr->function_pids); + trace_filter_add_remove_task(pid_list, self, task); +} + +static void +ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) +{ + struct trace_pid_list *pid_list; + struct trace_array *tr = data; + + pid_list = rcu_dereference_sched(tr->function_pids); + trace_filter_add_remove_task(pid_list, NULL, task); +} + +void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) +{ + if (enable) { + register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, + tr); + register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, + tr); + } else { + unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, + tr); + unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, + tr); + } +} + static void clear_ftrace_pids(struct trace_array *tr) { struct trace_pid_list *pid_list; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b5d4b80f2d45..8a5064a03ddf 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -257,7 +257,7 @@ unsigned long long ns2usecs(u64 nsec) /* trace_flags that are default zero for instances */ #define ZEROED_TRACE_FLAGS \ - TRACE_ITER_EVENT_FORK + (TRACE_ITER_EVENT_FORK | TRACE_ITER_FUNC_FORK) /* * The global_trace is the descriptor that holds the top-level tracing @@ -4205,6 +4205,9 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) if (mask == TRACE_ITER_EVENT_FORK) trace_event_follow_fork(tr, enabled); + if (mask == TRACE_ITER_FUNC_FORK) + ftrace_pid_follow_fork(tr, enabled); + if (mask == TRACE_ITER_OVERWRITE) { ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled); #ifdef CONFIG_TRACER_MAX_TRACE diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 571acee52a32..31a4997b67c6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -897,6 +897,7 @@ void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer); void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d_tracer); int init_function_trace(void); +void ftrace_pid_follow_fork(struct trace_array *tr, bool enable); #else static inline int ftrace_trace_task(struct trace_array *tr) { @@ -916,6 +917,7 @@ static inline void ftrace_reset_array_ops(struct trace_array *tr) { } static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { } static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { } static inline int init_function_trace(void) { return 0; } +static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { } /* ftace_func_t type is not defined, use macro instead of static inline */ #define ftrace_init_array_ops(tr, func) do { } while (0) #endif /* CONFIG_FUNCTION_TRACER */ @@ -989,11 +991,13 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf, #ifdef CONFIG_FUNCTION_TRACER # define FUNCTION_FLAGS \ - C(FUNCTION, "function-trace"), + C(FUNCTION, "function-trace"), \ + C(FUNC_FORK, "function-fork"), # define FUNCTION_DEFAULT_FLAGS TRACE_ITER_FUNCTION #else # define FUNCTION_FLAGS # define FUNCTION_DEFAULT_FLAGS 0UL +# define TRACE_ITER_FUNC_FORK 0UL #endif #ifdef CONFIG_STACKTRACE |