tracing/core: drop the old trace_printk() implementation in favour of trace_bprintk()
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>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 46b3cd7..cc94f86 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1169,6 +1169,67 @@
}
#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 @@
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 @@
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)
{