diff options
Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c new file mode 100644 index 00000000000..d31d695174a --- /dev/null +++ b/kernel/trace/trace_functions_graph.c @@ -0,0 +1,175 @@ +/* + * + * Function graph tracer. + * Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com> + * Mostly borrowed from function tracer which + * is Copyright (c) Steven Rostedt <srostedt@redhat.com> + * + */ +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/ftrace.h> +#include <linux/fs.h> + +#include "trace.h" + +#define TRACE_GRAPH_INDENT 2 + +#define TRACE_GRAPH_PRINT_OVERRUN 0x1 +static struct tracer_opt trace_opts[] = { + /* Display overruns or not */ + { TRACER_OPT(overrun, TRACE_GRAPH_PRINT_OVERRUN) }, + { } /* Empty entry */ +}; + +static struct tracer_flags tracer_flags = { + .val = 0, /* Don't display overruns by default */ + .opts = trace_opts +}; + +/* pid on the last trace processed */ +static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 }; + +static int graph_trace_init(struct trace_array *tr) +{ + int cpu, ret; + + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); + + ret = register_ftrace_graph(&trace_graph_return, + &trace_graph_entry); + if (ret) + return ret; + tracing_start_cmdline_record(); + + return 0; +} + +static void graph_trace_reset(struct trace_array *tr) +{ + tracing_stop_cmdline_record(); + unregister_ftrace_graph(); +} + +/* If the pid changed since the last trace, output this event */ +static int verif_pid(struct trace_seq *s, pid_t pid, int cpu) +{ + char *comm; + + if (last_pid[cpu] != -1 && last_pid[cpu] == pid) + return 1; + + last_pid[cpu] = pid; + comm = trace_find_cmdline(pid); + + return trace_seq_printf(s, "\nCPU[%03d]" + " ------------8<---------- thread %s-%d" + " ------------8<----------\n\n", + cpu, comm, pid); +} + +static enum print_line_t +print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s, + struct trace_entry *ent, int cpu) +{ + int i; + int ret; + + 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++) { + ret = trace_seq_printf(s, " "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } + + ret = seq_print_ip_sym(s, call->func, 0); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + ret = trace_seq_printf(s, "() {\n"); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + return TRACE_TYPE_HANDLED; +} + +static enum print_line_t +print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, + struct trace_entry *ent, int cpu) +{ + int i; + int ret; + + 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++) { + ret = trace_seq_printf(s, " "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } + + ret = trace_seq_printf(s, "} "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + ret = trace_seq_printf(s, "%llu\n", trace->rettime - trace->calltime); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) { + ret = trace_seq_printf(s, " (Overruns: %lu)\n", + trace->overrun); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + } + return TRACE_TYPE_HANDLED; +} + +enum print_line_t +print_graph_function(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + struct trace_entry *entry = iter->ent; + + switch (entry->type) { + case TRACE_GRAPH_ENT: { + struct ftrace_graph_ent_entry *field; + trace_assign_type(field, 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, iter->cpu); + } + default: + return TRACE_TYPE_UNHANDLED; + } +} + +static struct tracer graph_trace __read_mostly = { + .name = "function-graph", + .init = graph_trace_init, + .reset = graph_trace_reset, + .print_line = print_graph_function, + .flags = &tracer_flags, +}; + +static __init int init_graph_trace(void) +{ + return register_tracer(&graph_trace); +} + +device_initcall(init_graph_trace); |