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>

1 files changed, 6 insertions, 3 deletions

diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index c401b908e805..23e346a734ca 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -254,15 +254,18 @@ static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
 {
         struct trace_entry *entry = iter->ent;
         struct print_entry *print = (struct print_entry *)entry;
-        const char *msg         = print->buf;
         struct trace_seq *s     = &iter->seq;
         unsigned long long t    = ns2usecs(iter->ts);
-        unsigned long usec_rem  = do_div(t, 1000000ULL);
+        unsigned long usec_rem  = do_div(t, USEC_PER_SEC);
         unsigned secs           = (unsigned long)t;
         int ret;
 
         /* The trailing newline must be in the message. */
-        ret = trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg);
+        ret = trace_seq_printf(s, "MARK %u.%06lu ", secs, usec_rem);
+        if (!ret)
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        ret = trace_seq_bprintf(s, print->fmt, print->buf);
         if (!ret)
                 return TRACE_TYPE_PARTIAL_LINE;