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| author | Johannes Berg <johannes.berg@intel.com> | 2011-11-24 20:03:08 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2012-02-13 19:46:05 +0100 |
| commit | 95100358491abaa2e9a5483811370059bbca4645 (patch) | |
| tree | 4fc32c4bf2ef4416b4a914f5426f96ba58f29ec1 | |
| parent | ftrace: Append wakeup_rt description of ftrace doc (diff) | |
| download | linux-95100358491abaa2e9a5483811370059bbca4645.tar.xz linux-95100358491abaa2e9a5483811370059bbca4645.zip | |
printk/tracing: Add console output tracing
Add a printk.console trace point to record any printk
messages into the trace, regardless of the current
console loglevel. This can help correlate (existing)
printk debugging with other tracing.
Link: http://lkml.kernel.org/r/1322161388.5366.54.camel@jlt3.sipsolutions.net
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | include/trace/events/printk.h | 41 | ||||
| -rw-r--r-- | kernel/printk.c | 5 |
2 files changed, 46 insertions, 0 deletions
diff --git a/include/trace/events/printk.h b/include/trace/events/printk.h new file mode 100644 index 000000000000..94ec79cc011a --- /dev/null +++ b/include/trace/events/printk.h @@ -0,0 +1,41 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM printk + +#if !defined(_TRACE_PRINTK_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PRINTK_H + +#include <linux/tracepoint.h> + +TRACE_EVENT_CONDITION(console, + TP_PROTO(const char *log_buf, unsigned start, unsigned end, + unsigned log_buf_len), + + TP_ARGS(log_buf, start, end, log_buf_len), + + TP_CONDITION(start != end), + + TP_STRUCT__entry( + __dynamic_array(char, msg, end - start + 1) + ), + + TP_fast_assign( + if ((start & (log_buf_len - 1)) > (end & (log_buf_len - 1))) { + memcpy(__get_dynamic_array(msg), + log_buf + (start & (log_buf_len - 1)), + log_buf_len - (start & (log_buf_len - 1))); + memcpy((char *)__get_dynamic_array(msg) + + log_buf_len - (start & (log_buf_len - 1)), + log_buf, end & (log_buf_len - 1)); + } else + memcpy(__get_dynamic_array(msg), + log_buf + (start & (log_buf_len - 1)), + end - start); + ((char *)__get_dynamic_array(msg))[end - start] = 0; + ), + + TP_printk("%s", __get_str(msg)) +); +#endif /* _TRACE_PRINTK_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/kernel/printk.c b/kernel/printk.c index 13c0a1143f49..cb8a6bd697c6 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -44,6 +44,9 @@ #include <asm/uaccess.h> +#define CREATE_TRACE_POINTS +#include <trace/events/printk.h> + /* * Architectures can override it: */ @@ -542,6 +545,8 @@ MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to" static void _call_console_drivers(unsigned start, unsigned end, int msg_log_level) { + trace_console(&LOG_BUF(0), start, end, log_buf_len); + if ((msg_log_level < console_loglevel || ignore_loglevel) && console_drivers && start != end) { if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) { |