kernel-fxtec-pro1x/kernel/trace/trace_power.c
Steven Rostedt e77405ad80 tracing: pass around ring buffer instead of tracer
The latency tracers (irqsoff and wakeup) can swap trace buffers
on the fly. If an event is happening and has reserved data on one of
the buffers, and the latency tracer swaps the global buffer with the
max buffer, the result is that the event may commit the data to the
wrong buffer.

This patch changes the API to the trace recording to be recieve the
buffer that was used to reserve a commit. Then this buffer can be passed
in to the commit.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-04 18:59:39 -04:00

218 lines
5.1 KiB
C

/*
* ring buffer based C-state tracer
*
* Arjan van de Ven <arjan@linux.intel.com>
* Copyright (C) 2008 Intel Corporation
*
* Much is borrowed from trace_boot.c which is
* Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
*
*/
#include <linux/init.h>
#include <linux/debugfs.h>
#include <trace/power.h>
#include <linux/kallsyms.h>
#include <linux/module.h>
#include "trace.h"
#include "trace_output.h"
static struct trace_array *power_trace;
static int __read_mostly trace_power_enabled;
static void probe_power_start(struct power_trace *it, unsigned int type,
unsigned int level)
{
if (!trace_power_enabled)
return;
memset(it, 0, sizeof(struct power_trace));
it->state = level;
it->type = type;
it->stamp = ktime_get();
}
static void probe_power_end(struct power_trace *it)
{
struct ftrace_event_call *call = &event_power;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
struct trace_power *entry;
struct trace_array_cpu *data;
struct trace_array *tr = power_trace;
if (!trace_power_enabled)
return;
buffer = tr->buffer;
preempt_disable();
it->end = ktime_get();
data = tr->data[smp_processor_id()];
event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
sizeof(*entry), 0, 0);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->state_data = *it;
if (!filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit(buffer, event, 0, 0);
out:
preempt_enable();
}
static void probe_power_mark(struct power_trace *it, unsigned int type,
unsigned int level)
{
struct ftrace_event_call *call = &event_power;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
struct trace_power *entry;
struct trace_array_cpu *data;
struct trace_array *tr = power_trace;
if (!trace_power_enabled)
return;
buffer = tr->buffer;
memset(it, 0, sizeof(struct power_trace));
it->state = level;
it->type = type;
it->stamp = ktime_get();
preempt_disable();
it->end = it->stamp;
data = tr->data[smp_processor_id()];
event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
sizeof(*entry), 0, 0);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->state_data = *it;
if (!filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit(buffer, event, 0, 0);
out:
preempt_enable();
}
static int tracing_power_register(void)
{
int ret;
ret = register_trace_power_start(probe_power_start);
if (ret) {
pr_info("power trace: Couldn't activate tracepoint"
" probe to trace_power_start\n");
return ret;
}
ret = register_trace_power_end(probe_power_end);
if (ret) {
pr_info("power trace: Couldn't activate tracepoint"
" probe to trace_power_end\n");
goto fail_start;
}
ret = register_trace_power_mark(probe_power_mark);
if (ret) {
pr_info("power trace: Couldn't activate tracepoint"
" probe to trace_power_mark\n");
goto fail_end;
}
return ret;
fail_end:
unregister_trace_power_end(probe_power_end);
fail_start:
unregister_trace_power_start(probe_power_start);
return ret;
}
static void start_power_trace(struct trace_array *tr)
{
trace_power_enabled = 1;
}
static void stop_power_trace(struct trace_array *tr)
{
trace_power_enabled = 0;
}
static void power_trace_reset(struct trace_array *tr)
{
trace_power_enabled = 0;
unregister_trace_power_start(probe_power_start);
unregister_trace_power_end(probe_power_end);
unregister_trace_power_mark(probe_power_mark);
}
static int power_trace_init(struct trace_array *tr)
{
power_trace = tr;
trace_power_enabled = 1;
tracing_power_register();
tracing_reset_online_cpus(tr);
return 0;
}
static enum print_line_t power_print_line(struct trace_iterator *iter)
{
int ret = 0;
struct trace_entry *entry = iter->ent;
struct trace_power *field ;
struct power_trace *it;
struct trace_seq *s = &iter->seq;
struct timespec stamp;
struct timespec duration;
trace_assign_type(field, entry);
it = &field->state_data;
stamp = ktime_to_timespec(it->stamp);
duration = ktime_to_timespec(ktime_sub(it->end, it->stamp));
if (entry->type == TRACE_POWER) {
if (it->type == POWER_CSTATE)
ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n",
stamp.tv_sec,
stamp.tv_nsec,
it->state, iter->cpu,
duration.tv_sec,
duration.tv_nsec);
if (it->type == POWER_PSTATE)
ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n",
stamp.tv_sec,
stamp.tv_nsec,
it->state, iter->cpu);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
return TRACE_TYPE_UNHANDLED;
}
static void power_print_header(struct seq_file *s)
{
seq_puts(s, "# TIMESTAMP STATE EVENT\n");
seq_puts(s, "# | | |\n");
}
static struct tracer power_tracer __read_mostly =
{
.name = "power",
.init = power_trace_init,
.start = start_power_trace,
.stop = stop_power_trace,
.reset = power_trace_reset,
.print_line = power_print_line,
.print_header = power_print_header,
};
static int init_power_trace(void)
{
return register_tracer(&power_tracer);
}
device_initcall(init_power_trace);