diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2008-12-03 21:36:58 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-04 09:09:35 +0100 |
| commit | 0ef8cde56ab92ab3f65221246dc1622c6b5068b3 (patch) | |
| tree | 47bbb117a76146a5f5b949f00cf743dd3b31f873 /kernel | |
| parent | ftrace: graph of a single function (diff) | |
| download | linux-0ef8cde56ab92ab3f65221246dc1622c6b5068b3.tar.xz linux-0ef8cde56ab92ab3f65221246dc1622c6b5068b3.zip | |
ftrace: use task struct trace flag to filter on pid
Impact: clean up
Use the new task struct trace flags to determine if a process should be
traced or not.
Note: this moves the searching of the pid to the slow path of setting
the pid field. This needs to be converted to the pid name space.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b17a30350f06..c5049f54a275 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -47,7 +47,7 @@ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; -/* ftrace_pid_trace >= 0 will only trace threads with this pid */ +/* set when tracing only a pid */ static int ftrace_pid_trace = -1; /* Quick disabling of function tracer. */ @@ -90,7 +90,7 @@ static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) { - if (current->pid != ftrace_pid_trace) + if (!test_tsk_trace_trace(current)) return; ftrace_pid_function(ip, parent_ip); @@ -1714,11 +1714,33 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf, ftrace_pid_trace = -1; } else { + struct task_struct *p; + int found = 0; if (ftrace_pid_trace == val) goto out; - ftrace_pid_trace = val; + /* + * Find the task that matches this pid. + * TODO: use pid namespaces instead. + */ + rcu_read_lock(); + for_each_process(p) { + if (p->pid == val) { + found = 1; + set_tsk_trace_trace(p); + } else if (test_tsk_trace_trace(p)) + clear_tsk_trace_trace(p); + } + rcu_read_unlock(); + + if (found) + ftrace_pid_trace = val; + else { + if (ftrace_pid_trace < 0) + goto out; + ftrace_pid_trace = -1; + } } /* update the function call */ |