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tracing: Move trace_flags from global to a trace_array field
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In preparation to make trace options per instance, the global trace_flags
needs to be moved from being a global variable to a field within the trace
instance trace_array structure.

There's still more work to do, as there's some functions that use
trace_flags without passing in a way to get to the current_trace array. For
those, the global_trace is used directly (from trace.c). This includes
setting and clearing the trace_flags. This means that when a new instance is
created, it just gets the trace_flags of the global_trace and will not be
able to modify them. Depending on the functions that have access to the
trace_array, the flags of an instance may not affect parts of its trace,
where the global_trace is used. These will be fixed in future changes.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Steven Rostedt (Red Hat) committed Sep 30, 2015
1 parent 5557720 commit 983f938
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Showing 10 changed files with 135 additions and 101 deletions.
7 changes: 4 additions & 3 deletions kernel/trace/blktrace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1343,6 +1343,7 @@ static const struct {
static enum print_line_t print_one_line(struct trace_iterator *iter,
bool classic)
{
struct trace_array *tr = iter->tr;
struct trace_seq *s = &iter->seq;
const struct blk_io_trace *t;
u16 what;
Expand All @@ -1351,7 +1352,7 @@ static enum print_line_t print_one_line(struct trace_iterator *iter,

t = te_blk_io_trace(iter->ent);
what = t->action & ((1 << BLK_TC_SHIFT) - 1);
long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
long_act = !!(tr->trace_flags & TRACE_ITER_VERBOSE);
log_action = classic ? &blk_log_action_classic : &blk_log_action;

if (t->action == BLK_TN_MESSAGE) {
Expand Down Expand Up @@ -1413,9 +1414,9 @@ blk_tracer_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
/* don't output context-info for blk_classic output */
if (bit == TRACE_BLK_OPT_CLASSIC) {
if (set)
trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
tr->trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
else
trace_flags |= TRACE_ITER_CONTEXT_INFO;
tr->trace_flags |= TRACE_ITER_CONTEXT_INFO;
}
return 0;
}
Expand Down
92 changes: 54 additions & 38 deletions kernel/trace/trace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -250,6 +250,14 @@ unsigned long long ns2usecs(cycle_t nsec)
return nsec;
}

/* trace_flags holds trace_options default values */
#define TRACE_DEFAULT_FLAGS \
(FUNCTION_DEFAULT_FLAGS | \
TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | \
TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | \
TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | \
TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS)

/*
* The global_trace is the descriptor that holds the tracing
* buffers for the live tracing. For each CPU, it contains
Expand All @@ -262,7 +270,9 @@ unsigned long long ns2usecs(cycle_t nsec)
* pages for the buffer for that CPU. Each CPU has the same number
* of pages allocated for its buffer.
*/
static struct trace_array global_trace;
static struct trace_array global_trace = {
.trace_flags = TRACE_DEFAULT_FLAGS,
};

LIST_HEAD(ftrace_trace_arrays);

Expand Down Expand Up @@ -490,15 +500,6 @@ static inline void ftrace_trace_stack(struct ring_buffer *buffer,

#endif

/* trace_flags holds trace_options default values */
unsigned long trace_flags =
FUNCTION_DEFAULT_FLAGS |
TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO |
TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE |
TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS
;

static void tracer_tracing_on(struct trace_array *tr)
{
if (tr->trace_buffer.buffer)
Expand Down Expand Up @@ -543,7 +544,7 @@ int __trace_puts(unsigned long ip, const char *str, int size)
int alloc;
int pc;

if (!(trace_flags & TRACE_ITER_PRINTK))
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
return 0;

pc = preempt_count();
Expand Down Expand Up @@ -593,7 +594,7 @@ int __trace_bputs(unsigned long ip, const char *str)
int size = sizeof(struct bputs_entry);
int pc;

if (!(trace_flags & TRACE_ITER_PRINTK))
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
return 0;

pc = preempt_count();
Expand Down Expand Up @@ -1875,7 +1876,7 @@ static inline void ftrace_trace_stack(struct ring_buffer *buffer,
unsigned long flags,
int skip, int pc, struct pt_regs *regs)
{
if (!(trace_flags & TRACE_ITER_STACKTRACE))
if (!(global_trace.trace_flags & TRACE_ITER_STACKTRACE))
return;

__ftrace_trace_stack(buffer, flags, skip, pc, regs);
Expand Down Expand Up @@ -1919,7 +1920,7 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
struct userstack_entry *entry;
struct stack_trace trace;

if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE))
return;

/*
Expand Down Expand Up @@ -2236,7 +2237,7 @@ int trace_array_printk(struct trace_array *tr,
int ret;
va_list ap;

if (!(trace_flags & TRACE_ITER_PRINTK))
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
return 0;

va_start(ap, fmt);
Expand All @@ -2251,7 +2252,7 @@ int trace_array_printk_buf(struct ring_buffer *buffer,
int ret;
va_list ap;

if (!(trace_flags & TRACE_ITER_PRINTK))
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
return 0;

va_start(ap, fmt);
Expand Down Expand Up @@ -2592,7 +2593,7 @@ static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file
void
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
{
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK);
struct trace_buffer *buf = iter->trace_buffer;
struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu);
struct tracer *type = iter->trace;
Expand Down Expand Up @@ -2654,8 +2655,9 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
static void test_cpu_buff_start(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct trace_array *tr = iter->tr;

if (!(trace_flags & TRACE_ITER_ANNOTATE))
if (!(tr->trace_flags & TRACE_ITER_ANNOTATE))
return;

if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
Expand All @@ -2677,8 +2679,9 @@ static void test_cpu_buff_start(struct trace_iterator *iter)

static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
{
struct trace_array *tr = iter->tr;
struct trace_seq *s = &iter->seq;
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
struct trace_entry *entry;
struct trace_event *event;

Expand All @@ -2688,7 +2691,7 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)

event = ftrace_find_event(entry->type);

if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
if (iter->iter_flags & TRACE_FILE_LAT_FMT)
trace_print_lat_context(iter);
else
Expand All @@ -2708,13 +2711,14 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)

static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
{
struct trace_array *tr = iter->tr;
struct trace_seq *s = &iter->seq;
struct trace_entry *entry;
struct trace_event *event;

entry = iter->ent;

if (trace_flags & TRACE_ITER_CONTEXT_INFO)
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO)
trace_seq_printf(s, "%d %d %llu ",
entry->pid, iter->cpu, iter->ts);

Expand All @@ -2732,14 +2736,15 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)

static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
{
struct trace_array *tr = iter->tr;
struct trace_seq *s = &iter->seq;
unsigned char newline = '\n';
struct trace_entry *entry;
struct trace_event *event;

entry = iter->ent;

if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
SEQ_PUT_HEX_FIELD(s, entry->pid);
SEQ_PUT_HEX_FIELD(s, iter->cpu);
SEQ_PUT_HEX_FIELD(s, iter->ts);
Expand All @@ -2761,13 +2766,14 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)

static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
{
struct trace_array *tr = iter->tr;
struct trace_seq *s = &iter->seq;
struct trace_entry *entry;
struct trace_event *event;

entry = iter->ent;

if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
SEQ_PUT_FIELD(s, entry->pid);
SEQ_PUT_FIELD(s, iter->cpu);
SEQ_PUT_FIELD(s, iter->ts);
Expand Down Expand Up @@ -2816,6 +2822,8 @@ int trace_empty(struct trace_iterator *iter)
/* Called with trace_event_read_lock() held. */
enum print_line_t print_trace_line(struct trace_iterator *iter)
{
struct trace_array *tr = iter->tr;
unsigned long trace_flags = tr->trace_flags;
enum print_line_t ret;

if (iter->lost_events) {
Expand Down Expand Up @@ -2861,6 +2869,7 @@ enum print_line_t print_trace_line(struct trace_iterator *iter)
void trace_latency_header(struct seq_file *m)
{
struct trace_iterator *iter = m->private;
struct trace_array *tr = iter->tr;

/* print nothing if the buffers are empty */
if (trace_empty(iter))
Expand All @@ -2869,13 +2878,15 @@ void trace_latency_header(struct seq_file *m)
if (iter->iter_flags & TRACE_FILE_LAT_FMT)
print_trace_header(m, iter);

if (!(trace_flags & TRACE_ITER_VERBOSE))
if (!(tr->trace_flags & TRACE_ITER_VERBOSE))
print_lat_help_header(m);
}

void trace_default_header(struct seq_file *m)
{
struct trace_iterator *iter = m->private;
struct trace_array *tr = iter->tr;
unsigned long trace_flags = tr->trace_flags;

if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
return;
Expand Down Expand Up @@ -3220,7 +3231,7 @@ static int tracing_open(struct inode *inode, struct file *file)
iter = __tracing_open(inode, file, false);
if (IS_ERR(iter))
ret = PTR_ERR(iter);
else if (trace_flags & TRACE_ITER_LATENCY_FMT)
else if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
iter->iter_flags |= TRACE_FILE_LAT_FMT;
}

Expand Down Expand Up @@ -3467,7 +3478,7 @@ static int tracing_trace_options_show(struct seq_file *m, void *v)
trace_opts = tr->current_trace->flags->opts;

for (i = 0; trace_options[i]; i++) {
if (trace_flags & (1 << i))
if (tr->trace_flags & (1 << i))
seq_printf(m, "%s\n", trace_options[i]);
else
seq_printf(m, "no%s\n", trace_options[i]);
Expand Down Expand Up @@ -3532,7 +3543,7 @@ int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set)
int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
{
/* do nothing if flag is already set */
if (!!(trace_flags & mask) == !!enabled)
if (!!(tr->trace_flags & mask) == !!enabled)
return 0;

/* Give the tracer a chance to approve the change */
Expand All @@ -3541,9 +3552,9 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
return -EINVAL;

if (enabled)
trace_flags |= mask;
tr->trace_flags |= mask;
else
trace_flags &= ~mask;
tr->trace_flags &= ~mask;

if (mask == TRACE_ITER_RECORD_CMD)
trace_event_enable_cmd_record(enabled);
Expand Down Expand Up @@ -4558,7 +4569,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
/* trace pipe does not show start of buffer */
cpumask_setall(iter->started);

if (trace_flags & TRACE_ITER_LATENCY_FMT)
if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
iter->iter_flags |= TRACE_FILE_LAT_FMT;

/* Output in nanoseconds only if we are using a clock in nanoseconds. */
Expand Down Expand Up @@ -4615,11 +4626,13 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
static unsigned int
trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table)
{
struct trace_array *tr = iter->tr;

/* Iterators are static, they should be filled or empty */
if (trace_buffer_iter(iter, iter->cpu_file))
return POLLIN | POLLRDNORM;

if (trace_flags & TRACE_ITER_BLOCK)
if (tr->trace_flags & TRACE_ITER_BLOCK)
/*
* Always select as readable when in blocking mode
*/
Expand Down Expand Up @@ -5036,7 +5049,7 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp)
struct trace_array *tr = inode->i_private;

/* disable tracing ? */
if (trace_flags & TRACE_ITER_STOP_ON_FREE)
if (tr->trace_flags & TRACE_ITER_STOP_ON_FREE)
tracer_tracing_off(tr);
/* resize the ring buffer to 0 */
tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);
Expand Down Expand Up @@ -5069,7 +5082,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
if (tracing_disabled)
return -EINVAL;

if (!(trace_flags & TRACE_ITER_MARKERS))
if (!(tr->trace_flags & TRACE_ITER_MARKERS))
return -EINVAL;

if (cnt > TRACE_BUF_SIZE)
Expand Down Expand Up @@ -6180,7 +6193,7 @@ trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
long index = (long)filp->private_data;
char *buf;

if (trace_flags & (1 << index))
if (global_trace.trace_flags & (1 << index))
buf = "1\n";
else
buf = "0\n";
Expand Down Expand Up @@ -6407,7 +6420,7 @@ allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size
{
enum ring_buffer_flags rb_flags;

rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;
rb_flags = tr->trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;

buf->tr = tr;

Expand Down Expand Up @@ -6502,6 +6515,8 @@ static int instance_mkdir(const char *name)
if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL))
goto out_free_tr;

tr->trace_flags = global_trace.trace_flags;

cpumask_copy(tr->tracing_cpumask, cpu_all_mask);

raw_spin_lock_init(&tr->start_lock);
Expand Down Expand Up @@ -6938,6 +6953,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
/* use static because iter can be a bit big for the stack */
static struct trace_iterator iter;
static atomic_t dump_running;
struct trace_array *tr = &global_trace;
unsigned int old_userobj;
unsigned long flags;
int cnt = 0, cpu;
Expand Down Expand Up @@ -6967,10 +6983,10 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
}

old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ;
old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ;

/* don't look at user memory in panic mode */
trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ;

switch (oops_dump_mode) {
case DUMP_ALL:
Expand Down Expand Up @@ -7033,7 +7049,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
printk(KERN_TRACE "---------------------------------\n");

out_enable:
trace_flags |= old_userobj;
tr->trace_flags |= old_userobj;

for_each_tracing_cpu(cpu) {
atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
Expand Down
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