int ftrace_enabled __read_mostly;
static int last_ftrace_enabled;
+/* Quick disabling of function tracer. */
+int function_trace_stop;
+
+ ++/* By default, current tracing type is normal tracing. */
+ ++enum ftrace_tracing_type_t ftrace_tracing_type = FTRACE_TYPE_ENTER;
+ ++
/*
* ftrace_disabled is set when an anomaly is discovered.
* ftrace_disabled is much stronger than ftrace_enabled.
return;
mutex_lock(&ftrace_start_lock);
- ftrace_start++;
- if (ftrace_start == 1)
- command |= FTRACE_ENABLE_CALLS;
+ ftrace_start_up++;
- - if (ftrace_start_up == 1)
- - command |= FTRACE_ENABLE_CALLS;
+ ++ command |= FTRACE_ENABLE_CALLS;
if (saved_ftrace_func != ftrace_trace_function) {
saved_ftrace_func = ftrace_trace_function;
mutex_lock(&ftrace_sysctl_lock);
mutex_lock(&ftrace_start_lock);
- - if (iter->filtered && ftrace_start_up && ftrace_enabled)
- if (iter->filtered && ftrace_start && ftrace_enabled)
+ ++ if (ftrace_start_up && ftrace_enabled)
ftrace_run_update_code(FTRACE_ENABLE_CALLS);
mutex_unlock(&ftrace_start_lock);
mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
- - void register_ftrace_return(trace_function_return_t func)
+#ifdef CONFIG_FUNCTION_RET_TRACER
+ ++
+ ++/* The callback that hooks the return of a function */
+trace_function_return_t ftrace_function_return =
+ (trace_function_return_t)ftrace_stub;
+ ++
+ ++int register_ftrace_return(trace_function_return_t func)
+{
+ ++ int ret = 0;
+ ++
+ ++ mutex_lock(&ftrace_sysctl_lock);
+ ++
+ ++ /*
+ ++ * Don't launch return tracing if normal function
+ ++ * tracing is already running.
+ ++ */
+ ++ if (ftrace_trace_function != ftrace_stub) {
+ ++ ret = -EBUSY;
+ ++ goto out;
+ ++ }
+ ++
+ ++ ftrace_tracing_type = FTRACE_TYPE_RETURN;
+ ftrace_function_return = func;
+ ++ ftrace_startup();
+ ++
+ ++out:
+ ++ mutex_unlock(&ftrace_sysctl_lock);
+ ++ return ret;
+}
+
+void unregister_ftrace_return(void)
+{
+ ++ mutex_lock(&ftrace_sysctl_lock);
+ ++
+ ftrace_function_return = (trace_function_return_t)ftrace_stub;
+ ++ ftrace_shutdown();
+ ++ /* Restore normal tracing type */
+ ++ ftrace_tracing_type = FTRACE_TYPE_ENTER;
+ ++
+ ++ mutex_unlock(&ftrace_sysctl_lock);
+}
+#endif
+
+
+
--- /dev/null
-- local_irq_save(flags);
+/*
+ * unlikely profiler
+ *
+ * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
+ */
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/ftrace.h>
+#include <linux/hash.h>
+#include <linux/fs.h>
+#include <asm/local.h>
+#include "trace.h"
+
+#ifdef CONFIG_BRANCH_TRACER
+
+static int branch_tracing_enabled __read_mostly;
+static DEFINE_MUTEX(branch_tracing_mutex);
+static struct trace_array *branch_tracer;
+
+static void
+probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+{
+ struct trace_array *tr = branch_tracer;
+ struct ring_buffer_event *event;
+ struct trace_branch *entry;
+ unsigned long flags, irq_flags;
+ int cpu, pc;
+ const char *p;
+
+ /*
+ * I would love to save just the ftrace_likely_data pointer, but
+ * this code can also be used by modules. Ugly things can happen
+ * if the module is unloaded, and then we go and read the
+ * pointer. This is slower, but much safer.
+ */
+
+ if (unlikely(!tr))
+ return;
+
-- local_irq_restore(flags);
+++ raw_local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
+ goto out;
+
+ event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+ &irq_flags);
+ if (!event)
+ goto out;
+
+ pc = preempt_count();
+ entry = ring_buffer_event_data(event);
+ tracing_generic_entry_update(&entry->ent, flags, pc);
+ entry->ent.type = TRACE_BRANCH;
+
+ /* Strip off the path, only save the file */
+ p = f->file + strlen(f->file);
+ while (p >= f->file && *p != '/')
+ p--;
+ p++;
+
+ strncpy(entry->func, f->func, TRACE_FUNC_SIZE);
+ strncpy(entry->file, p, TRACE_FILE_SIZE);
+ entry->func[TRACE_FUNC_SIZE] = 0;
+ entry->file[TRACE_FILE_SIZE] = 0;
+ entry->line = f->line;
+ entry->correct = val == expect;
+
+ ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+ out:
+ atomic_dec(&tr->data[cpu]->disabled);
- - static void branch_trace_init(struct trace_array *tr)
+++ raw_local_irq_restore(flags);
+}
+
+static inline
+void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+{
+ if (!branch_tracing_enabled)
+ return;
+
+ probe_likely_condition(f, val, expect);
+}
+
+int enable_branch_tracing(struct trace_array *tr)
+{
+ int ret = 0;
+
+ mutex_lock(&branch_tracing_mutex);
+ branch_tracer = tr;
+ /*
+ * Must be seen before enabling. The reader is a condition
+ * where we do not need a matching rmb()
+ */
+ smp_wmb();
+ branch_tracing_enabled++;
+ mutex_unlock(&branch_tracing_mutex);
+
+ return ret;
+}
+
+void disable_branch_tracing(void)
+{
+ mutex_lock(&branch_tracing_mutex);
+
+ if (!branch_tracing_enabled)
+ goto out_unlock;
+
+ branch_tracing_enabled--;
+
+ out_unlock:
+ mutex_unlock(&branch_tracing_mutex);
+}
+
+static void start_branch_trace(struct trace_array *tr)
+{
+ enable_branch_tracing(tr);
+}
+
+static void stop_branch_trace(struct trace_array *tr)
+{
+ disable_branch_tracing();
+}
+
+ ++static int branch_trace_init(struct trace_array *tr)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ tracing_reset(tr, cpu);
+
+ start_branch_trace(tr);
+ ++ return 0;
+}
+
+static void branch_trace_reset(struct trace_array *tr)
+{
+ stop_branch_trace(tr);
+}
+
+struct tracer branch_trace __read_mostly =
+{
+ .name = "branch",
+ .init = branch_trace_init,
+ .reset = branch_trace_reset,
+#ifdef CONFIG_FTRACE_SELFTEST
+ .selftest = trace_selftest_startup_branch,
+#endif
+};
+
+__init static int init_branch_trace(void)
+{
+ return register_tracer(&branch_trace);
+}
+
+device_initcall(init_branch_trace);
+#else
+static inline
+void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+{
+}
+#endif /* CONFIG_BRANCH_TRACER */
+
+void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect)
+{
+ /*
+ * I would love to have a trace point here instead, but the
+ * trace point code is so inundated with unlikely and likely
+ * conditions that the recursive nightmare that exists is too
+ * much to try to get working. At least for now.
+ */
+ trace_likely_condition(f, val, expect);
+
+ /* FIXME: Make this atomic! */
+ if (val == expect)
+ f->correct++;
+ else
+ f->incorrect++;
+}
+EXPORT_SYMBOL(ftrace_likely_update);
+
+struct ftrace_pointer {
+ void *start;
+ void *stop;
+};
+
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct ftrace_pointer *f = m->private;
+ struct ftrace_branch_data *p = v;
+
+ (*pos)++;
+
+ if (v == (void *)1)
+ return f->start;
+
+ ++p;
+
+ if ((void *)p >= (void *)f->stop)
+ return NULL;
+
+ return p;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+ void *t = (void *)1;
+ loff_t l = 0;
+
+ for (; t && l < *pos; t = t_next(m, t, &l))
+ ;
+
+ return t;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+ struct ftrace_branch_data *p = v;
+ const char *f;
+ unsigned long percent;
+
+ if (v == (void *)1) {
+ seq_printf(m, " correct incorrect %% "
+ " Function "
+ " File Line\n"
+ " ------- --------- - "
+ " -------- "
+ " ---- ----\n");
+ return 0;
+ }
+
+ /* Only print the file, not the path */
+ f = p->file + strlen(p->file);
+ while (f >= p->file && *f != '/')
+ f--;
+ f++;
+
+ if (p->correct) {
+ percent = p->incorrect * 100;
+ percent /= p->correct + p->incorrect;
+ } else
+ percent = p->incorrect ? 100 : 0;
+
+ seq_printf(m, "%8lu %8lu %3lu ", p->correct, p->incorrect, percent);
+ seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line);
+ return 0;
+}
+
+static struct seq_operations tracing_likely_seq_ops = {
+ .start = t_start,
+ .next = t_next,
+ .stop = t_stop,
+ .show = t_show,
+};
+
+static int tracing_likely_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = seq_open(file, &tracing_likely_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = (void *)inode->i_private;
+ }
+
+ return ret;
+}
+
+static struct file_operations tracing_likely_fops = {
+ .open = tracing_likely_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+};
+
+extern unsigned long __start_likely_profile[];
+extern unsigned long __stop_likely_profile[];
+extern unsigned long __start_unlikely_profile[];
+extern unsigned long __stop_unlikely_profile[];
+
+static struct ftrace_pointer ftrace_likely_pos = {
+ .start = __start_likely_profile,
+ .stop = __stop_likely_profile,
+};
+
+static struct ftrace_pointer ftrace_unlikely_pos = {
+ .start = __start_unlikely_profile,
+ .stop = __stop_unlikely_profile,
+};
+
+static __init int ftrace_branch_init(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *entry;
+
+ d_tracer = tracing_init_dentry();
+
+ entry = debugfs_create_file("profile_likely", 0444, d_tracer,
+ &ftrace_likely_pos,
+ &tracing_likely_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'profile_likely' entry\n");
+
+ entry = debugfs_create_file("profile_unlikely", 0444, d_tracer,
+ &ftrace_unlikely_pos,
+ &tracing_likely_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs"
+ " 'profile_unlikely' entry\n");
+
+ return 0;
+}
+
+device_initcall(ftrace_branch_init);
git.openpandora.org / pandora-kernel.git / commitdiff