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author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-03-09 06:40:58 +0100 |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2013-03-15 05:35:56 +0100 |
commit | ca268da6e415448a43138e1abc5d5f057af319d7 (patch) | |
tree | 33fcaf68989e12fca96ad86bdece7eaac16d1545 /kernel/trace/trace.h | |
parent | tracing: Optimize trace_printk() with one arg to use trace_puts() (diff) | |
download | linux-ca268da6e415448a43138e1abc5d5f057af319d7.tar.xz linux-ca268da6e415448a43138e1abc5d5f057af319d7.zip |
tracing: Add internal ftrace trace_puts() for ftrace to use
There's a few places that ftrace uses trace_printk() for internal
use, but this requires context (normal, softirq, irq, NMI) buffers
to keep things lockless. But the trace_puts() does not, as it can
write the string directly into the ring buffer. Make a internal helper
for trace_puts() and have the internal functions use that.
This way the extra context buffers are not used.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
-rw-r--r-- | kernel/trace/trace.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index d5764a8532e2..0e430b401ab6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1040,6 +1040,17 @@ void trace_printk_start_comm(void); int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set); int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled); +/* + * Normal trace_printk() and friends allocates special buffers + * to do the manipulation, as well as saves the print formats + * into sections to display. But the trace infrastructure wants + * to use these without the added overhead at the price of being + * a bit slower (used mainly for warnings, where we don't care + * about performance). The internal_trace_puts() is for such + * a purpose. + */ +#define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str)) + #undef FTRACE_ENTRY #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter) \ extern struct ftrace_event_call \ |