#include <linux/hardirq.h>
#include <linux/kthread.h>
#include <linux/uaccess.h>
-#include <linux/kprobes.h>
#include <linux/ftrace.h>
#include <linux/sysctl.h>
+#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/list.h>
#include <linux/hash.h>
+#include <linux/rcupdate.h>
#include <trace/events/sched.h>
ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
+/*
+ * Traverse the ftrace_list, invoking all entries. The reason that we
+ * can use rcu_dereference_raw() is that elements removed from this list
+ * are simply leaked, so there is no need to interact with a grace-period
+ * mechanism. The rcu_dereference_raw() calls are needed to handle
+ * concurrent insertions into the ftrace_list.
+ *
+ * Silly Alpha and silly pointer-speculation compiler optimizations!
+ */
static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
{
- struct ftrace_ops *op = ftrace_list;
-
- /* in case someone actually ports this to alpha! */
- read_barrier_depends();
+ struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/
while (op != &ftrace_list_end) {
- /* silly alpha */
- read_barrier_depends();
op->func(ip, parent_ip);
- op = op->next;
+ op = rcu_dereference_raw(op->next); /*see above*/
};
}
* the ops->next pointer is valid before another CPU sees
* the ops pointer included into the ftrace_list.
*/
- smp_wmb();
- ftrace_list = ops;
+ rcu_assign_pointer(ftrace_list, ops);
if (ftrace_enabled) {
ftrace_func_t func;
unsigned long counter;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
unsigned long long time;
+ unsigned long long time_squared;
#endif
};
{
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
seq_printf(m, " Function "
- "Hit Time Avg\n"
+ "Hit Time Avg s^2\n"
" -------- "
- "--- ---- ---\n");
+ "--- ---- --- ---\n");
#else
seq_printf(m, " Function Hit\n"
" -------- ---\n");
static DEFINE_MUTEX(mutex);
static struct trace_seq s;
unsigned long long avg;
+ unsigned long long stddev;
#endif
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
avg = rec->time;
do_div(avg, rec->counter);
+ /* Sample standard deviation (s^2) */
+ if (rec->counter <= 1)
+ stddev = 0;
+ else {
+ stddev = rec->time_squared - rec->counter * avg * avg;
+ /*
+ * Divide only 1000 for ns^2 -> us^2 conversion.
+ * trace_print_graph_duration will divide 1000 again.
+ */
+ do_div(stddev, (rec->counter - 1) * 1000);
+ }
+
mutex_lock(&mutex);
trace_seq_init(&s);
trace_print_graph_duration(rec->time, &s);
trace_seq_puts(&s, " ");
trace_print_graph_duration(avg, &s);
+ trace_seq_puts(&s, " ");
+ trace_print_graph_duration(stddev, &s);
trace_print_seq(m, &s);
mutex_unlock(&mutex);
#endif
if (!stat->hash || !ftrace_profile_enabled)
goto out;
+ /* If the calltime was zero'd ignore it */
+ if (!trace->calltime)
+ goto out;
+
calltime = trace->rettime - trace->calltime;
if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
}
rec = ftrace_find_profiled_func(stat, trace->func);
- if (rec)
+ if (rec) {
rec->time += calltime;
+ rec->time_squared += calltime * calltime;
+ }
out:
local_irq_restore(flags);
} \
}
-#ifdef CONFIG_KPROBES
-
-static int frozen_record_count;
-
-static inline void freeze_record(struct dyn_ftrace *rec)
-{
- if (!(rec->flags & FTRACE_FL_FROZEN)) {
- rec->flags |= FTRACE_FL_FROZEN;
- frozen_record_count++;
- }
-}
-
-static inline void unfreeze_record(struct dyn_ftrace *rec)
-{
- if (rec->flags & FTRACE_FL_FROZEN) {
- rec->flags &= ~FTRACE_FL_FROZEN;
- frozen_record_count--;
- }
-}
-
-static inline int record_frozen(struct dyn_ftrace *rec)
-{
- return rec->flags & FTRACE_FL_FROZEN;
-}
-#else
-# define freeze_record(rec) ({ 0; })
-# define unfreeze_record(rec) ({ 0; })
-# define record_frozen(rec) ({ 0; })
-#endif /* CONFIG_KPROBES */
-
static void ftrace_free_rec(struct dyn_ftrace *rec)
{
rec->freelist = ftrace_free_records;
}
+/* Return 1 if the address range is reserved for ftrace */
+int ftrace_text_reserved(void *start, void *end)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+
+ do_for_each_ftrace_rec(pg, rec) {
+ if (rec->ip <= (unsigned long)end &&
+ rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start)
+ return 1;
+ } while_for_each_ftrace_rec();
+ return 0;
+}
+
+
static int
__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
!(rec->flags & FTRACE_FL_CONVERTED))
continue;
- /* ignore updates to this record's mcount site */
- if (get_kprobe((void *)rec->ip)) {
- freeze_record(rec);
- continue;
- } else {
- unfreeze_record(rec);
- }
-
failed = __ftrace_replace_code(rec, enable);
if (failed) {
rec->flags |= FTRACE_FL_FAILED;
}
static void
-ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev,
- struct task_struct *next)
+ftrace_graph_probe_sched_switch(void *ignore,
+ struct task_struct *prev, struct task_struct *next)
{
unsigned long long timestamp;
int index;
} while (ret == -EAGAIN);
if (!ret) {
- ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch);
+ ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
if (ret)
pr_info("ftrace_graph: Couldn't activate tracepoint"
" probe to kernel_sched_switch\n");
goto out;
ftrace_graph_active--;
- unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
ftrace_graph_entry = ftrace_graph_entry_stub;
ftrace_shutdown(FTRACE_STOP_FUNC_RET);
unregister_pm_notifier(&ftrace_suspend_notifier);
+ unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
out:
mutex_unlock(&ftrace_lock);
{
/* Make sure we do not use the parent ret_stack */
t->ret_stack = NULL;
+ t->curr_ret_stack = -1;
if (ftrace_graph_active) {
struct ftrace_ret_stack *ret_stack;
GFP_KERNEL);
if (!ret_stack)
return;
- t->curr_ret_stack = -1;
atomic_set(&t->tracing_graph_pause, 0);
atomic_set(&t->trace_overrun, 0);
t->ftrace_timestamp = 0;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff