diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-03-09 00:40:58 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-03-15 00:35:56 -0400 |
| commit | ca268da6e415448a43138e1abc5d5f057af319d7 (patch) | |
| tree | 33fcaf68989e12fca96ad86bdece7eaac16d1545 /kernel/trace | |
| parent | 9d3c752c062e3266f1051ba0825276ea1e2777da (diff) | |
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')
| -rw-r--r-- | kernel/trace/trace.c | 8 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 11 |
2 files changed, 15 insertions, 4 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5043a0c4dde..d372c6504c9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -443,16 +443,16 @@ void tracing_snapshot(void) unsigned long flags; if (!tr->allocated_snapshot) { - trace_printk("*** SNAPSHOT NOT ALLOCATED ***\n"); - trace_printk("*** stopping trace here! ***\n"); + internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n"); + internal_trace_puts("*** stopping trace here! ***\n"); tracing_off(); return; } /* Note, snapshot can not be used when the tracer uses it */ if (tracer->use_max_tr) { - trace_printk("*** LATENCY TRACER ACTIVE ***\n"); - trace_printk("*** Can not use snapshot (sorry) ***\n"); + internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n"); + internal_trace_puts("*** Can not use snapshot (sorry) ***\n"); return; } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index d5764a8532e..0e430b401ab 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 \ |