diff options
Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 78 |
1 files changed, 54 insertions, 24 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index b1342c5d37cf..e998a824e9db 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -18,6 +18,7 @@ struct fgraph_cpu_data { pid_t last_pid; int depth; int ignore; + unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH]; }; struct fgraph_data { @@ -212,13 +213,11 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) int cpu; int pc; - if (unlikely(!tr)) - return 0; - if (!ftrace_trace_task(current)) return 0; - if (!ftrace_graph_addr(trace->func)) + /* trace it when it is-nested-in or is a function enabled. */ + if (!(trace->depth || ftrace_graph_addr(trace->func))) return 0; local_irq_save(flags); @@ -231,9 +230,6 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) } else { ret = 0; } - /* Only do the atomic if it is not already set */ - if (!test_tsk_trace_graph(current)) - set_tsk_trace_graph(current); atomic_dec(&data->disabled); local_irq_restore(flags); @@ -281,17 +277,24 @@ void trace_graph_return(struct ftrace_graph_ret *trace) pc = preempt_count(); __trace_graph_return(tr, trace, flags, pc); } - if (!trace->depth) - clear_tsk_trace_graph(current); atomic_dec(&data->disabled); local_irq_restore(flags); } +void set_graph_array(struct trace_array *tr) +{ + graph_array = tr; + + /* Make graph_array visible before we start tracing */ + + smp_mb(); +} + static int graph_trace_init(struct trace_array *tr) { int ret; - graph_array = tr; + set_graph_array(tr); ret = register_ftrace_graph(&trace_graph_return, &trace_graph_entry); if (ret) @@ -301,11 +304,6 @@ static int graph_trace_init(struct trace_array *tr) return 0; } -void set_graph_array(struct trace_array *tr) -{ - graph_array = tr; -} - static void graph_trace_reset(struct trace_array *tr) { tracing_stop_cmdline_record(); @@ -673,15 +671,21 @@ print_graph_entry_leaf(struct trace_iterator *iter, duration = graph_ret->rettime - graph_ret->calltime; if (data) { + struct fgraph_cpu_data *cpu_data; int cpu = iter->cpu; - int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); + + cpu_data = per_cpu_ptr(data->cpu_data, cpu); /* * Comments display at + 1 to depth. Since * this is a leaf function, keep the comments * equal to this depth. */ - *depth = call->depth - 1; + cpu_data->depth = call->depth - 1; + + /* No need to keep this function around for this depth */ + if (call->depth < FTRACE_RETFUNC_DEPTH) + cpu_data->enter_funcs[call->depth] = 0; } /* Overhead */ @@ -721,10 +725,15 @@ print_graph_entry_nested(struct trace_iterator *iter, int i; if (data) { + struct fgraph_cpu_data *cpu_data; int cpu = iter->cpu; - int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); - *depth = call->depth; + cpu_data = per_cpu_ptr(data->cpu_data, cpu); + cpu_data->depth = call->depth; + + /* Save this function pointer to see if the exit matches */ + if (call->depth < FTRACE_RETFUNC_DEPTH) + cpu_data->enter_funcs[call->depth] = call->func; } /* No overhead */ @@ -854,19 +863,28 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, struct fgraph_data *data = iter->private; pid_t pid = ent->pid; int cpu = iter->cpu; + int func_match = 1; int ret; int i; if (data) { + struct fgraph_cpu_data *cpu_data; int cpu = iter->cpu; - int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); + + cpu_data = per_cpu_ptr(data->cpu_data, cpu); /* * Comments display at + 1 to depth. This is the * return from a function, we now want the comments * to display at the same level of the bracket. */ - *depth = trace->depth - 1; + cpu_data->depth = trace->depth - 1; + + if (trace->depth < FTRACE_RETFUNC_DEPTH) { + if (cpu_data->enter_funcs[trace->depth] != trace->func) + func_match = 0; + cpu_data->enter_funcs[trace->depth] = 0; + } } if (print_graph_prologue(iter, s, 0, 0)) @@ -891,9 +909,21 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, return TRACE_TYPE_PARTIAL_LINE; } - ret = trace_seq_printf(s, "}\n"); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + /* + * If the return function does not have a matching entry, + * then the entry was lost. Instead of just printing + * the '}' and letting the user guess what function this + * belongs to, write out the function name. + */ + if (func_match) { + ret = trace_seq_printf(s, "}\n"); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } else { + ret = trace_seq_printf(s, "} (%ps)\n", (void *)trace->func); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } /* Overrun */ if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) { |