diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-03-09 02:02:34 (GMT) |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-03-15 04:35:55 (GMT) |
| commit | 09ae72348eccb60e304cf8ce94653f4a78fcd407 (patch) | |
| tree | 28c48644f71df4752556d9f5b15efb889e57af56 /kernel/trace/trace.h | |
| parent | 153e8ed913b022d2003866a848af9fadc041403f (diff) | |
| download | linux-fsl-qoriq-09ae72348eccb60e304cf8ce94653f4a78fcd407.tar.xz | |
tracing: Add trace_puts() for even faster trace_printk() tracing
The trace_printk() is extremely fast and is very handy as it can be
used in any context (including NMIs!). But it still requires scanning
the fmt string for parsing the args. Even the trace_bprintk() requires
a scan to know what args will be saved, although it doesn't copy the
format string itself.
Several times trace_printk() has no args, and wastes cpu cycles scanning
the fmt string.
Adding trace_puts() allows the developer to use an even faster
tracing method that only saves the pointer to the string in the
ring buffer without doing any format parsing at all. This will
help remove even more of the "Heisenbug" effect, when debugging.
Also fixed up the F_printk()s for the ftrace internal bprint and print events.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 26bc718..d5764a8 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -34,6 +34,7 @@ enum trace_type { TRACE_GRAPH_ENT, TRACE_USER_STACK, TRACE_BLK, + TRACE_BPUTS, __TRACE_LAST_TYPE, }; @@ -277,6 +278,7 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\ IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \ + IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ TRACE_MMIO_RW); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ |