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tracing/core: drop the old trace_printk() implementation in favour of trace_bprintk()

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Impact: faster and lighter tracing

Now that we have trace_bprintk() which is faster and consume lesser
memory than trace_printk() and has the same purpose, we can now drop
the old implementation in favour of the binary one from trace_bprintk(),
which means we move all the implementation of trace_bprintk() to
trace_printk(), so the Api doesn't change except that we must now use
trace_seq_bprintk() to print the TRACE_PRINT entries.

Some changes result of this:

- Previously, trace_bprintk depended of a single tracer and couldn't
  work without. This tracer has been dropped and the whole implementation
  of trace_printk() (like the module formats management) is now integrated
  in the tracing core (comes with CONFIG_TRACING), though we keep the file
  trace_printk (previously trace_bprintk.c) where we can find the module
  management. Thus we don't overflow trace.c

- changes some parts to use trace_seq_bprintk() to print TRACE_PRINT entries.

- change a bit trace_printk/trace_vprintk macros to support non-builtin formats
  constants, and fix 'const' qualifiers warnings. But this is all transparent for
  developers.

- etc...

V2:

- Rebase against last changes
- Fix mispell on the changelog

V3:

- Rebase against last changes (moving trace_printk() to kernel.h)

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236356510-8381-5-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Frederic Weisbecker
2009-03-06 17:21:49 +01:00
committed by Ingo Molnar
parent 1ba28e02a1
commit 769b0441f4
12 changed files with 164 additions and 315 deletions
Download Patch File Download Diff File Expand all files Collapse all files

212
kernel/trace/trace.c
View File

@@ -1169,6 +1169,67 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
/**
* trace_vprintk - write binary msg to tracing buffer
*
*/
int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
{
static DEFINE_SPINLOCK(trace_buf_lock);
static u32 trace_buf[TRACE_BUF_SIZE];
struct ring_buffer_event *event;
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
struct print_entry *entry;
unsigned long flags;
int resched;
int cpu, len = 0, size, pc;
if (unlikely(tracing_selftest_running || tracing_disabled))
return 0;
/* Don't pollute graph traces with trace_vprintk internals */
pause_graph_tracing();
pc = preempt_count();
resched = ftrace_preempt_disable();
cpu = raw_smp_processor_id();
data = tr->data[cpu];
if (unlikely(atomic_read(&data->disabled)))
goto out;
spin_lock_irqsave(&trace_buf_lock, flags);
len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args);
if (len > TRACE_BUF_SIZE || len < 0)
goto out_unlock;
size = sizeof(*entry) + sizeof(u32) * len;
event = trace_buffer_lock_reserve(tr, TRACE_PRINT, size, flags, pc);
if (!event)
goto out_unlock;
entry = ring_buffer_event_data(event);
entry->ip = ip;
entry->depth = depth;
entry->fmt = fmt;
memcpy(entry->buf, trace_buf, sizeof(u32) * len);
ring_buffer_unlock_commit(tr->buffer, event);
out_unlock:
spin_unlock_irqrestore(&trace_buf_lock, flags);
out:
ftrace_preempt_enable(resched);
unpause_graph_tracing();
return len;
}
EXPORT_SYMBOL_GPL(trace_vprintk);
enum trace_file_type {
TRACE_FILE_LAT_FMT = 1,
TRACE_FILE_ANNOTATE = 2,
@@ -1564,7 +1625,7 @@ static enum print_line_t print_printk_msg_only(struct trace_iterator *iter)
trace_assign_type(field, entry);
ret = trace_seq_printf(s, "%s", field->buf);
ret = trace_seq_bprintf(s, field->fmt, field->buf);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -3714,155 +3775,6 @@ static __init int tracer_init_debugfs(void)
return 0;
}
int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
{
static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED;
static char trace_buf[TRACE_BUF_SIZE];
struct ring_buffer_event *event;
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
int cpu, len = 0, size, pc;
struct print_entry *entry;
unsigned long irq_flags;
if (tracing_disabled || tracing_selftest_running)
return 0;
pc = preempt_count();
preempt_disable_notrace();
cpu = raw_smp_processor_id();
data = tr->data[cpu];
if (unlikely(atomic_read(&data->disabled)))
goto out;
pause_graph_tracing();
raw_local_irq_save(irq_flags);
__raw_spin_lock(&trace_buf_lock);
len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
len = min(len, TRACE_BUF_SIZE-1);
trace_buf[len] = 0;
size = sizeof(*entry) + len + 1;
event = trace_buffer_lock_reserve(tr, TRACE_PRINT, size, irq_flags, pc);
if (!event)
goto out_unlock;
entry = ring_buffer_event_data(event);
entry->ip = ip;
entry->depth = depth;
memcpy(&entry->buf, trace_buf, len);
entry->buf[len] = 0;
ring_buffer_unlock_commit(tr->buffer, event);
out_unlock:
__raw_spin_unlock(&trace_buf_lock);
raw_local_irq_restore(irq_flags);
unpause_graph_tracing();
out:
preempt_enable_notrace();
return len;
}
EXPORT_SYMBOL_GPL(trace_vprintk);
int __trace_printk(unsigned long ip, const char *fmt, ...)
{
int ret;
va_list ap;
if (!(trace_flags & TRACE_ITER_PRINTK))
return 0;
va_start(ap, fmt);
ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
va_end(ap);
return ret;
}
EXPORT_SYMBOL_GPL(__trace_printk);
int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap)
{
if (!(trace_flags & TRACE_ITER_PRINTK))
return 0;
return trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
}
EXPORT_SYMBOL_GPL(__ftrace_vprintk);
/**
* trace_vbprintk - write binary msg to tracing buffer
*
* Caller must insure @fmt are valid when msg is in tracing buffer.
*/
int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
{
static DEFINE_SPINLOCK(trace_buf_lock);
static u32 trace_buf[TRACE_BUF_SIZE];
struct ring_buffer_event *event;
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
struct bprintk_entry *entry;
unsigned long flags;
int resched;
int cpu, len = 0, size, pc;
if (tracing_disabled || !trace_bprintk_enable)
return 0;
pc = preempt_count();
resched = ftrace_preempt_disable();
cpu = raw_smp_processor_id();
data = tr->data[cpu];
if (unlikely(atomic_read(&data->disabled)))
goto out;
spin_lock_irqsave(&trace_buf_lock, flags);
len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args);
if (len > TRACE_BUF_SIZE || len < 0)
goto out_unlock;
size = sizeof(*entry) + sizeof(u32) * len;
event = trace_buffer_lock_reserve(tr, TRACE_BPRINTK, size, flags, pc);
if (!event)
goto out_unlock;
entry = ring_buffer_event_data(event);
entry->ip = ip;
entry->fmt = fmt;
memcpy(entry->buf, trace_buf, sizeof(u32) * len);
ring_buffer_unlock_commit(tr->buffer, event);
out_unlock:
spin_unlock_irqrestore(&trace_buf_lock, flags);
out:
ftrace_preempt_enable(resched);
return len;
}
EXPORT_SYMBOL_GPL(trace_vbprintk);
int __trace_bprintk(unsigned long ip, const char *fmt, ...)
{
int ret;
va_list ap;
if (!fmt)
return 0;
va_start(ap, fmt);
ret = trace_vbprintk(ip, fmt, ap);
va_end(ap);
return ret;
}
EXPORT_SYMBOL_GPL(__trace_bprintk);
static int trace_panic_handler(struct notifier_block *this,
unsigned long event, void *unused)
{