Messages in this thread | | | Subject | Re: [PATCH] printk: add console output tracing | From | Steven Rostedt <> | Date | Wed, 16 Nov 2011 20:01:28 -0500 |
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Thomas, Peter, Frederic, Christoph,
Would you ack this patch please.
Thanks,
-- Steve
On Wed, 2011-11-16 at 22:25 +0100, Johannes Berg wrote: > From: Johannes Berg <johannes.berg@intel.com> > > 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. > > Signed-off-by: Johannes Berg <johannes.berg@intel.com> > --- > include/trace/events/printk.h | 44 ++++++++++++++++++++++++++++++++++++++++++ > kernel/printk.c | 3 ++ > kernel/trace/Makefile | 1 > kernel/trace/printk-trace.c | 14 +++++++++++++ > 4 files changed, 62 insertions(+) > > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > +++ b/include/trace/events/printk.h 2011-11-16 22:06:43.000000000 +0100 > @@ -0,0 +1,44 @@ > +#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 + log_buf_len) & > + (log_buf_len - 1)) + 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 + log_buf_len) & (log_buf_len - 1)); > + ((char *)__get_dynamic_array(msg))[(end - start + log_buf_len) & > + (log_buf_len - 1)] = 0; > + ), > + > + TP_printk("%s", __get_str(msg)) > +); > +#endif /* _TRACE_PRINTK_H */ > + > +/* This part must be outside protection */ > +#include <trace/define_trace.h> > --- a/kernel/printk.c 2011-11-16 16:37:20.000000000 +0100 > +++ b/kernel/printk.c 2011-11-16 21:47:20.000000000 +0100 > @@ -41,6 +41,7 @@ > #include <linux/cpu.h> > #include <linux/notifier.h> > #include <linux/rculist.h> > +#include <trace/events/printk.h> > > #include <asm/uaccess.h> > > @@ -542,6 +543,8 @@ MODULE_PARM_DESC(ignore_loglevel, "ignor > 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)) { > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > +++ b/kernel/trace/printk-trace.c 2011-11-16 21:22:20.000000000 +0100 > @@ -0,0 +1,14 @@ > +/* > + * printk trace points > + * > + * Copyright (C) 2011 Johannes Berg <johannes.berg@intel.com> > + */ > + > +#include <linux/string.h> > +#include <linux/types.h> > +#include <linux/workqueue.h> > +#include <linux/sched.h> > +#include <linux/module.h> > + > +#define CREATE_TRACE_POINTS > +#include <trace/events/printk.h> > --- a/kernel/trace/Makefile 2011-11-16 16:37:20.000000000 +0100 > +++ b/kernel/trace/Makefile 2011-11-16 21:38:49.000000000 +0100 > @@ -55,6 +55,7 @@ endif > obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o > obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o > obj-$(CONFIG_TRACEPOINTS) += power-traces.o > +obj-$(CONFIG_TRACEPOINTS) += printk-trace.o > ifeq ($(CONFIG_PM_RUNTIME),y) > obj-$(CONFIG_TRACEPOINTS) += rpm-traces.o > endif >
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