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authorSteven Rostedt <rostedt@goodmis.org>2008-11-26 00:16:27 -0500
committerIngo Molnar <mingo@elte.hu>2008-11-26 06:52:57 +0100
commit437f24fb897d409a9978eb71ecfaf279dcd94acd (patch)
tree6d84f5f7f3000c5560000c8c29a3af4494ffd0f7
parent660c7f9be96321fc80026d76411bd15e6f418a72 (diff)
ftrace: add cpu annotation for function graph tracer
Impact: enhancement for function graph tracer When run on a SMP box, the function graph tracer is confusing because it shows the different CPUS as changes in the trace. This patch adds the annotation of 'CPU[###]' where ### is a three digit number. The output will look similar to this: CPU[001] dput() { CPU[000] } 726 CPU[001] } 487 CPU[000] do_softirq() { CPU[001] } 2221 CPU[000] __do_softirq() { CPU[000] __local_bh_disable() { CPU[001] unroll_tree_refs() { CPU[000] } 569 CPU[001] } 501 CPU[000] rcu_process_callbacks() { CPU[001] kfree() { What makes this nice is that now you can grep the file and produce readable format for a particular CPU. # cat /debug/tracing/trace > /tmp/trace # grep '^CPU\[000\]' /tmp/trace > /tmp/trace0 # grep '^CPU\[001\]' /tmp/trace > /tmp/trace1 Will give you: # head /tmp/trace0 CPU[000] ------------8<---------- thread sshd-3899 ------------8<---------- CPU[000] inotify_dentry_parent_queue_event() { CPU[000] } 2531 CPU[000] inotify_inode_queue_event() { CPU[000] } 505 CPU[000] } 69626 CPU[000] } 73089 CPU[000] audit_syscall_exit() { CPU[000] path_put() { CPU[000] dput() { # head /tmp/trace1 CPU[001] ------------8<---------- thread pcscd-3446 ------------8<---------- CPU[001] } 4186 CPU[001] dput() { CPU[001] } 543 CPU[001] vfs_permission() { CPU[001] inode_permission() { CPU[001] shmem_permission() { CPU[001] generic_permission() { CPU[001] } 501 CPU[001] } 2205 Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/trace/trace_functions_graph.c34
1 files changed, 22 insertions, 12 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index bbb81e7b6c40..d31d695174aa 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -28,7 +28,7 @@ static struct tracer_flags tracer_flags = {
};
/* pid on the last trace processed */
-static pid_t last_pid = -1;
+static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
static int graph_trace_init(struct trace_array *tr)
{
@@ -53,29 +53,34 @@ static void graph_trace_reset(struct trace_array *tr)
}
/* If the pid changed since the last trace, output this event */
-static int verif_pid(struct trace_seq *s, pid_t pid)
+static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
{
char *comm;
- if (last_pid != -1 && last_pid == pid)
+ if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
return 1;
- last_pid = pid;
+ last_pid[cpu] = pid;
comm = trace_find_cmdline(pid);
- return trace_seq_printf(s, "\n------------8<---------- thread %s-%d"
+ return trace_seq_printf(s, "\nCPU[%03d]"
+ " ------------8<---------- thread %s-%d"
" ------------8<----------\n\n",
- comm, pid);
+ cpu, comm, pid);
}
static enum print_line_t
print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s,
- struct trace_entry *ent)
+ struct trace_entry *ent, int cpu)
{
int i;
int ret;
- if (!verif_pid(s, ent->pid))
+ if (!verif_pid(s, ent->pid, cpu))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
+ if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
@@ -96,12 +101,16 @@ print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s,
static enum print_line_t
print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
- struct trace_entry *ent)
+ struct trace_entry *ent, int cpu)
{
int i;
int ret;
- if (!verif_pid(s, ent->pid))
+ if (!verif_pid(s, ent->pid, cpu))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
+ if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
@@ -137,12 +146,13 @@ print_graph_function(struct trace_iterator *iter)
case TRACE_GRAPH_ENT: {
struct ftrace_graph_ent_entry *field;
trace_assign_type(field, entry);
- return print_graph_entry(&field->graph_ent, s, entry);
+ return print_graph_entry(&field->graph_ent, s, entry,
+ iter->cpu);
}
case TRACE_GRAPH_RET: {
struct ftrace_graph_ret_entry *field;
trace_assign_type(field, entry);
- return print_graph_return(&field->ret, s, entry);
+ return print_graph_return(&field->ret, s, entry, iter->cpu);
}
default:
return TRACE_TYPE_UNHANDLED;