Merge branch 'tracing/hw-branch-tracing' into tracing/core

Merge reason: this topic is ready for upstream now. It passed
              Oleg's review and Andrew had no further mm/*
              objections/observations either.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar
2009-05-07 11:18:34 +02:00
25 changed files with 1620 additions and 569 deletions
+6 -1
View File
@@ -15,12 +15,17 @@ ifdef CONFIG_TRACING_BRANCHES
KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
endif
#
# Make the trace clocks available generally: it's infrastructure
# relied on by ptrace for example:
#
obj-y += trace_clock.o
obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o
obj-$(CONFIG_RING_BUFFER) += ring_buffer.o
obj-$(CONFIG_RING_BUFFER_BENCHMARK) += ring_buffer_benchmark.o
obj-$(CONFIG_TRACING) += trace.o
obj-$(CONFIG_TRACING) += trace_clock.o
obj-$(CONFIG_TRACING) += trace_output.o
obj-$(CONFIG_TRACING) += trace_stat.o
obj-$(CONFIG_TRACING) += trace_printk.o
+2
View File
@@ -538,6 +538,8 @@ extern int trace_selftest_startup_sysprof(struct tracer *trace,
struct trace_array *tr);
extern int trace_selftest_startup_branch(struct tracer *trace,
struct trace_array *tr);
extern int trace_selftest_startup_hw_branches(struct tracer *trace,
struct trace_array *tr);
#endif /* CONFIG_FTRACE_STARTUP_TEST */
extern void *head_page(struct trace_array_cpu *data);
+104 -99
View File
@@ -1,10 +1,9 @@
/*
* h/w branch tracer for x86 based on bts
* h/w branch tracer for x86 based on BTS
*
* Copyright (C) 2008-2009 Intel Corporation.
* Markus Metzger <markus.t.metzger@gmail.com>, 2008-2009
*/
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/debugfs.h>
#include <linux/ftrace.h>
@@ -15,110 +14,119 @@
#include <asm/ds.h>
#include "trace.h"
#include "trace_output.h"
#include "trace.h"
#define SIZEOF_BTS (1 << 13)
#define BTS_BUFFER_SIZE (1 << 13)
/*
* The tracer lock protects the below per-cpu tracer array.
* It needs to be held to:
* - start tracing on all cpus
* - stop tracing on all cpus
* - start tracing on a single hotplug cpu
* - stop tracing on a single hotplug cpu
* - read the trace from all cpus
* - read the trace from a single cpu
*/
static DEFINE_SPINLOCK(bts_tracer_lock);
static DEFINE_PER_CPU(struct bts_tracer *, tracer);
static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer);
static DEFINE_PER_CPU(unsigned char[BTS_BUFFER_SIZE], buffer);
#define this_tracer per_cpu(tracer, smp_processor_id())
#define this_buffer per_cpu(buffer, smp_processor_id())
static int __read_mostly trace_hw_branches_enabled;
static int trace_hw_branches_enabled __read_mostly;
static int trace_hw_branches_suspended __read_mostly;
static struct trace_array *hw_branch_trace __read_mostly;
/*
* Start tracing on the current cpu.
* The argument is ignored.
*
* pre: bts_tracer_lock must be locked.
*/
static void bts_trace_start_cpu(void *arg)
static void bts_trace_init_cpu(int cpu)
{
if (this_tracer)
ds_release_bts(this_tracer);
per_cpu(tracer, cpu) =
ds_request_bts_cpu(cpu, per_cpu(buffer, cpu), BTS_BUFFER_SIZE,
NULL, (size_t)-1, BTS_KERNEL);
this_tracer =
ds_request_bts(/* task = */ NULL, this_buffer, SIZEOF_BTS,
/* ovfl = */ NULL, /* th = */ (size_t)-1,
BTS_KERNEL);
if (IS_ERR(this_tracer)) {
this_tracer = NULL;
return;
if (IS_ERR(per_cpu(tracer, cpu)))
per_cpu(tracer, cpu) = NULL;
}
static int bts_trace_init(struct trace_array *tr)
{
int cpu;
hw_branch_trace = tr;
trace_hw_branches_enabled = 0;
get_online_cpus();
for_each_online_cpu(cpu) {
bts_trace_init_cpu(cpu);
if (likely(per_cpu(tracer, cpu)))
trace_hw_branches_enabled = 1;
}
trace_hw_branches_suspended = 0;
put_online_cpus();
/* If we could not enable tracing on a single cpu, we fail. */
return trace_hw_branches_enabled ? 0 : -EOPNOTSUPP;
}
static void bts_trace_reset(struct trace_array *tr)
{
int cpu;
get_online_cpus();
for_each_online_cpu(cpu) {
if (likely(per_cpu(tracer, cpu))) {
ds_release_bts(per_cpu(tracer, cpu));
per_cpu(tracer, cpu) = NULL;
}
}
trace_hw_branches_enabled = 0;
trace_hw_branches_suspended = 0;
put_online_cpus();
}
static void bts_trace_start(struct trace_array *tr)
{
spin_lock(&bts_tracer_lock);
int cpu;
on_each_cpu(bts_trace_start_cpu, NULL, 1);
trace_hw_branches_enabled = 1;
spin_unlock(&bts_tracer_lock);
}
/*
* Stop tracing on the current cpu.
* The argument is ignored.
*
* pre: bts_tracer_lock must be locked.
*/
static void bts_trace_stop_cpu(void *arg)
{
if (this_tracer) {
ds_release_bts(this_tracer);
this_tracer = NULL;
}
get_online_cpus();
for_each_online_cpu(cpu)
if (likely(per_cpu(tracer, cpu)))
ds_resume_bts(per_cpu(tracer, cpu));
trace_hw_branches_suspended = 0;
put_online_cpus();
}
static void bts_trace_stop(struct trace_array *tr)
{
spin_lock(&bts_tracer_lock);
int cpu;
trace_hw_branches_enabled = 0;
on_each_cpu(bts_trace_stop_cpu, NULL, 1);
spin_unlock(&bts_tracer_lock);
get_online_cpus();
for_each_online_cpu(cpu)
if (likely(per_cpu(tracer, cpu)))
ds_suspend_bts(per_cpu(tracer, cpu));
trace_hw_branches_suspended = 1;
put_online_cpus();
}
static int __cpuinit bts_hotcpu_handler(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
spin_lock(&bts_tracer_lock);
if (!trace_hw_branches_enabled)
goto out;
int cpu = (long)hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_DOWN_FAILED:
smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1);
/* The notification is sent with interrupts enabled. */
if (trace_hw_branches_enabled) {
bts_trace_init_cpu(cpu);
if (trace_hw_branches_suspended &&
likely(per_cpu(tracer, cpu)))
ds_suspend_bts(per_cpu(tracer, cpu));
}
break;
case CPU_DOWN_PREPARE:
smp_call_function_single(cpu, bts_trace_stop_cpu, NULL, 1);
break;
/* The notification is sent with interrupts enabled. */
if (likely(per_cpu(tracer, cpu))) {
ds_release_bts(per_cpu(tracer, cpu));
per_cpu(tracer, cpu) = NULL;
}
}
out:
spin_unlock(&bts_tracer_lock);
return NOTIFY_DONE;
}
@@ -126,20 +134,6 @@ static struct notifier_block bts_hotcpu_notifier __cpuinitdata = {
.notifier_call = bts_hotcpu_handler
};
static int bts_trace_init(struct trace_array *tr)
{
hw_branch_trace = tr;
bts_trace_start(tr);
return 0;
}
static void bts_trace_reset(struct trace_array *tr)
{
bts_trace_stop(tr);
}
static void bts_trace_print_header(struct seq_file *m)
{
seq_puts(m, "# CPU# TO <- FROM\n");
@@ -147,10 +141,10 @@ static void bts_trace_print_header(struct seq_file *m)
static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
{
unsigned long symflags = TRACE_ITER_SYM_OFFSET;
struct trace_entry *entry = iter->ent;
struct trace_seq *seq = &iter->seq;
struct hw_branch_entry *it;
unsigned long symflags = TRACE_ITER_SYM_OFFSET;
trace_assign_type(it, entry);
@@ -226,11 +220,11 @@ static void trace_bts_at(const struct bts_trace *trace, void *at)
/*
* Collect the trace on the current cpu and write it into the ftrace buffer.
*
* pre: bts_tracer_lock must be locked
* pre: tracing must be suspended on the current cpu
*/
static void trace_bts_cpu(void *arg)
{
struct trace_array *tr = (struct trace_array *) arg;
struct trace_array *tr = (struct trace_array *)arg;
const struct bts_trace *trace;
unsigned char *at;
@@ -243,10 +237,9 @@ static void trace_bts_cpu(void *arg)
if (unlikely(!this_tracer))
return;
ds_suspend_bts(this_tracer);
trace = ds_read_bts(this_tracer);
if (!trace)
goto out;
return;
for (at = trace->ds.top; (void *)at < trace->ds.end;
at += trace->ds.size)
@@ -255,18 +248,27 @@ static void trace_bts_cpu(void *arg)
for (at = trace->ds.begin; (void *)at < trace->ds.top;
at += trace->ds.size)
trace_bts_at(trace, at);
out:
ds_resume_bts(this_tracer);
}
static void trace_bts_prepare(struct trace_iterator *iter)
{
spin_lock(&bts_tracer_lock);
int cpu;
get_online_cpus();
for_each_online_cpu(cpu)
if (likely(per_cpu(tracer, cpu)))
ds_suspend_bts(per_cpu(tracer, cpu));
/*
* We need to collect the trace on the respective cpu since ftrace
* implicitly adds the record for the current cpu.
* Once that is more flexible, we could collect the data from any cpu.
*/
on_each_cpu(trace_bts_cpu, iter->tr, 1);
spin_unlock(&bts_tracer_lock);
for_each_online_cpu(cpu)
if (likely(per_cpu(tracer, cpu)))
ds_resume_bts(per_cpu(tracer, cpu));
put_online_cpus();
}
static void trace_bts_close(struct trace_iterator *iter)
@@ -276,11 +278,11 @@ static void trace_bts_close(struct trace_iterator *iter)
void trace_hw_branch_oops(void)
{
spin_lock(&bts_tracer_lock);
trace_bts_cpu(hw_branch_trace);
spin_unlock(&bts_tracer_lock);
if (this_tracer) {
ds_suspend_bts_noirq(this_tracer);
trace_bts_cpu(hw_branch_trace);
ds_resume_bts_noirq(this_tracer);
}
}
struct tracer bts_tracer __read_mostly =
@@ -293,7 +295,10 @@ struct tracer bts_tracer __read_mostly =
.start = bts_trace_start,
.stop = bts_trace_stop,
.open = trace_bts_prepare,
.close = trace_bts_close
.close = trace_bts_close,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_hw_branches,
#endif /* CONFIG_FTRACE_SELFTEST */
};
__init static int init_bts_trace(void)
+58
View File
@@ -16,6 +16,7 @@ static inline int trace_valid_entry(struct trace_entry *entry)
case TRACE_BRANCH:
case TRACE_GRAPH_ENT:
case TRACE_GRAPH_RET:
case TRACE_HW_BRANCHES:
return 1;
}
return 0;
@@ -188,6 +189,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
#else
# define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; })
#endif /* CONFIG_DYNAMIC_FTRACE */
/*
* Simple verification test of ftrace function tracer.
* Enable ftrace, sleep 1/10 second, and then read the trace
@@ -749,3 +751,59 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
return ret;
}
#endif /* CONFIG_BRANCH_TRACER */
#ifdef CONFIG_HW_BRANCH_TRACER
int
trace_selftest_startup_hw_branches(struct tracer *trace,
struct trace_array *tr)
{
struct trace_iterator *iter;
struct tracer tracer;
unsigned long count;
int ret;
if (!trace->open) {
printk(KERN_CONT "missing open function...");
return -1;
}
ret = tracer_init(trace, tr);
if (ret) {
warn_failed_init_tracer(trace, ret);
return ret;
}
/*
* The hw-branch tracer needs to collect the trace from the various
* cpu trace buffers - before tracing is stopped.
*/
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
if (!iter)
return -ENOMEM;
memcpy(&tracer, trace, sizeof(tracer));
iter->trace = &tracer;
iter->tr = tr;
iter->pos = -1;
mutex_init(&iter->mutex);
trace->open(iter);
mutex_destroy(&iter->mutex);
kfree(iter);
tracing_stop();
ret = trace_test_buffer(tr, &count);
trace->reset(tr);
tracing_start();
if (!ret && !count) {
printk(KERN_CONT "no entries found..");
ret = -1;
}
return ret;
}
#endif /* CONFIG_HW_BRANCH_TRACER */