From 437f24fb897d409a9978eb71ecfaf279dcd94acd Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 26 Nov 2008 00:16:27 -0500 Subject: [PATCH] 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 Signed-off-by: Ingo Molnar --- kernel/trace/trace_functions_graph.c | 34 ++++++++++++++++++---------- 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index bbb81e7b6c4..d31d695174a 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; -- 2.20.1