2008-11-26 04:07:04 +08:00
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/*
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*
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* Function graph tracer.
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* Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
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* Mostly borrowed from function tracer which
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* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
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*
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*/
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#include <linux/debugfs.h>
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#include <linux/uaccess.h>
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#include <linux/ftrace.h>
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#include <linux/fs.h>
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#include "trace.h"
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2008-11-26 07:57:25 +08:00
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#define TRACE_GRAPH_INDENT 2
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2008-11-27 08:46:33 +08:00
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/* Spaces between function call and time duration */
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#define TRACE_GRAPH_TIMESPACE_ENTRY " "
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/* Spaces between function call and closing braces */
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#define TRACE_GRAPH_TIMESPACE_RET " "
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2008-11-26 04:07:04 +08:00
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#define TRACE_GRAPH_PRINT_OVERRUN 0x1
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static struct tracer_opt trace_opts[] = {
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/* Display overruns or not */
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{ TRACER_OPT(overrun, TRACE_GRAPH_PRINT_OVERRUN) },
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{ } /* Empty entry */
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};
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static struct tracer_flags tracer_flags = {
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.val = 0, /* Don't display overruns by default */
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.opts = trace_opts
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};
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2008-11-26 07:57:25 +08:00
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/* pid on the last trace processed */
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2008-11-26 13:16:27 +08:00
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static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
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2008-11-26 04:07:04 +08:00
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static int graph_trace_init(struct trace_array *tr)
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{
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2008-11-26 13:16:26 +08:00
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int cpu, ret;
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2008-11-26 04:07:04 +08:00
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for_each_online_cpu(cpu)
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tracing_reset(tr, cpu);
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2008-11-26 13:16:26 +08:00
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ret = register_ftrace_graph(&trace_graph_return,
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2008-11-26 07:57:25 +08:00
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&trace_graph_entry);
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2008-11-26 13:16:26 +08:00
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if (ret)
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return ret;
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tracing_start_cmdline_record();
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return 0;
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2008-11-26 04:07:04 +08:00
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}
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static void graph_trace_reset(struct trace_array *tr)
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{
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2008-11-26 13:16:26 +08:00
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tracing_stop_cmdline_record();
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unregister_ftrace_graph();
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2008-11-26 04:07:04 +08:00
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}
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2008-11-26 07:57:25 +08:00
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/* If the pid changed since the last trace, output this event */
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2008-11-26 13:16:27 +08:00
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static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
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2008-11-26 07:57:25 +08:00
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{
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2008-11-26 13:16:26 +08:00
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char *comm;
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2008-11-26 13:16:27 +08:00
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if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
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2008-11-26 07:57:25 +08:00
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return 1;
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2008-11-26 04:07:04 +08:00
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2008-11-26 13:16:27 +08:00
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last_pid[cpu] = pid;
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2008-11-26 13:16:26 +08:00
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comm = trace_find_cmdline(pid);
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2008-11-27 08:46:33 +08:00
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return trace_seq_printf(s, "\nCPU[%03d] "
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2008-11-26 13:16:27 +08:00
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" ------------8<---------- thread %s-%d"
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2008-11-26 07:57:25 +08:00
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" ------------8<----------\n\n",
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2008-11-26 13:16:27 +08:00
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cpu, comm, pid);
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2008-11-26 07:57:25 +08:00
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}
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2008-11-27 08:46:33 +08:00
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static bool
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trace_branch_is_leaf(struct trace_iterator *iter,
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struct ftrace_graph_ent_entry *curr)
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{
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struct ring_buffer_iter *ring_iter;
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struct ring_buffer_event *event;
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struct ftrace_graph_ret_entry *next;
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ring_iter = iter->buffer_iter[iter->cpu];
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if (!ring_iter)
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return false;
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event = ring_buffer_iter_peek(iter->buffer_iter[iter->cpu], NULL);
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if (!event)
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return false;
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next = ring_buffer_event_data(event);
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if (next->ent.type != TRACE_GRAPH_RET)
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return false;
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if (curr->ent.pid != next->ent.pid ||
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curr->graph_ent.func != next->ret.func)
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return false;
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return true;
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}
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static inline int
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print_graph_duration(unsigned long long duration, struct trace_seq *s)
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{
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unsigned long nsecs_rem = do_div(duration, 1000);
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return trace_seq_printf(s, "+ %llu.%lu us\n", duration, nsecs_rem);
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}
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/* Signal a overhead of time execution to the output */
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static int
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print_graph_overhead(unsigned long long duration, struct trace_seq *s)
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{
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/* Duration exceeded 100 msecs */
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if (duration > 100000ULL)
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return trace_seq_printf(s, "! ");
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/* Duration exceeded 10 msecs */
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if (duration > 10000ULL)
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return trace_seq_printf(s, "+ ");
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return trace_seq_printf(s, " ");
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}
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/* Case of a leaf function on its call entry */
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2008-11-26 07:57:25 +08:00
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static enum print_line_t
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2008-11-27 08:46:33 +08:00
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print_graph_entry_leaf(struct trace_iterator *iter,
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struct ftrace_graph_ent_entry *entry, struct trace_seq *s)
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2008-11-26 04:07:04 +08:00
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{
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2008-11-27 08:46:33 +08:00
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struct ftrace_graph_ret_entry *ret_entry;
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struct ftrace_graph_ret *graph_ret;
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struct ring_buffer_event *event;
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struct ftrace_graph_ent *call;
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unsigned long long duration;
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2008-11-26 07:57:25 +08:00
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int i;
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2008-11-26 04:07:04 +08:00
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int ret;
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2008-11-27 08:46:33 +08:00
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event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
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ret_entry = ring_buffer_event_data(event);
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graph_ret = &ret_entry->ret;
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call = &entry->graph_ent;
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duration = graph_ret->rettime - graph_ret->calltime;
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/* Overhead */
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ret = print_graph_overhead(duration, s);
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if (!ret)
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2008-11-26 13:16:27 +08:00
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-27 08:46:33 +08:00
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/* Function */
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for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
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ret = trace_seq_printf(s, " ");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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}
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ret = seq_print_ip_sym(s, call->func, 0);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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ret = trace_seq_printf(s, "();");
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2008-11-26 13:16:27 +08:00
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if (!ret)
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2008-11-26 07:57:25 +08:00
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-26 04:07:04 +08:00
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2008-11-27 08:46:33 +08:00
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/* Duration */
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ret = trace_seq_printf(s, TRACE_GRAPH_TIMESPACE_ENTRY);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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ret = print_graph_duration(duration, s);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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return TRACE_TYPE_HANDLED;
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}
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static enum print_line_t
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print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
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struct trace_seq *s)
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{
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int i;
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int ret;
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struct ftrace_graph_ent *call = &entry->graph_ent;
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/* No overhead */
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ret = trace_seq_printf(s, " ");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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/* Function */
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2008-11-26 07:57:25 +08:00
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for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
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ret = trace_seq_printf(s, " ");
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2008-11-26 04:07:04 +08:00
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-26 07:57:25 +08:00
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}
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ret = seq_print_ip_sym(s, call->func, 0);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-27 08:46:33 +08:00
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ret = trace_seq_printf(s, "() {");
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2008-11-26 07:57:25 +08:00
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-27 08:46:33 +08:00
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/* No duration to print at this state */
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ret = trace_seq_printf(s, TRACE_GRAPH_TIMESPACE_ENTRY "-\n");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-26 07:57:25 +08:00
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return TRACE_TYPE_HANDLED;
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}
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2008-11-27 08:46:33 +08:00
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static enum print_line_t
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print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
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struct trace_iterator *iter, int cpu)
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{
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int ret;
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struct trace_entry *ent = iter->ent;
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if (!verif_pid(s, ent->pid, cpu))
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return TRACE_TYPE_PARTIAL_LINE;
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ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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if (trace_branch_is_leaf(iter, field))
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return print_graph_entry_leaf(iter, field, s);
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else
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return print_graph_entry_nested(field, s);
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}
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2008-11-26 07:57:25 +08:00
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static enum print_line_t
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print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
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2008-11-26 13:16:27 +08:00
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struct trace_entry *ent, int cpu)
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2008-11-26 07:57:25 +08:00
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{
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int i;
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int ret;
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2008-11-27 08:46:33 +08:00
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unsigned long long duration = trace->rettime - trace->calltime;
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2008-11-26 07:57:25 +08:00
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2008-11-27 08:46:33 +08:00
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/* Pid */
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2008-11-26 13:16:27 +08:00
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if (!verif_pid(s, ent->pid, cpu))
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-27 08:46:33 +08:00
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/* Cpu */
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2008-11-26 13:16:27 +08:00
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ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
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if (!ret)
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2008-11-26 07:57:25 +08:00
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-26 04:07:04 +08:00
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2008-11-27 08:46:33 +08:00
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/* Overhead */
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ret = print_graph_overhead(duration, s);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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/* Closing brace */
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2008-11-26 07:57:25 +08:00
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for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
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ret = trace_seq_printf(s, " ");
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2008-11-26 04:07:04 +08:00
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-26 07:57:25 +08:00
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}
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ret = trace_seq_printf(s, "} ");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-26 04:07:04 +08:00
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2008-11-27 08:46:33 +08:00
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/* Duration */
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ret = trace_seq_printf(s, TRACE_GRAPH_TIMESPACE_RET);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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ret = print_graph_duration(duration, s);
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2008-11-26 07:57:25 +08:00
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-26 04:07:04 +08:00
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2008-11-27 08:46:33 +08:00
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/* Overrun */
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2008-11-26 07:57:25 +08:00
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if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
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ret = trace_seq_printf(s, " (Overruns: %lu)\n",
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trace->overrun);
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2008-11-26 04:07:04 +08:00
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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2008-11-26 07:57:25 +08:00
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}
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return TRACE_TYPE_HANDLED;
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}
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enum print_line_t
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print_graph_function(struct trace_iterator *iter)
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{
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struct trace_seq *s = &iter->seq;
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struct trace_entry *entry = iter->ent;
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2008-11-26 04:07:04 +08:00
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2008-11-26 07:57:25 +08:00
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switch (entry->type) {
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case TRACE_GRAPH_ENT: {
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struct ftrace_graph_ent_entry *field;
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trace_assign_type(field, entry);
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2008-11-27 08:46:33 +08:00
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return print_graph_entry(field, s, iter,
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2008-11-26 13:16:27 +08:00
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iter->cpu);
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2008-11-26 07:57:25 +08:00
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}
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case TRACE_GRAPH_RET: {
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struct ftrace_graph_ret_entry *field;
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trace_assign_type(field, entry);
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2008-11-26 13:16:27 +08:00
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return print_graph_return(&field->ret, s, entry, iter->cpu);
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2008-11-26 07:57:25 +08:00
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}
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default:
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return TRACE_TYPE_UNHANDLED;
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2008-11-26 04:07:04 +08:00
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}
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}
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static struct tracer graph_trace __read_mostly = {
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2008-11-27 08:46:33 +08:00
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.name = "function_graph",
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2008-11-26 04:07:04 +08:00
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.init = graph_trace_init,
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.reset = graph_trace_reset,
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.print_line = print_graph_function,
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.flags = &tracer_flags,
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};
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static __init int init_graph_trace(void)
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{
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return register_tracer(&graph_trace);
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}
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device_initcall(init_graph_trace);
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