Commit c87edb36 authored Aug 05, 2016 by Steven Rostedt (Red Hat) Committed by Steven Rostedt Aug 09, 2016

tracing: Fix tick_stop tracepoint symbols for user export



The symbols used in the tick_stop tracepoint were not being converted
properly into integers in the trace_stop format file. Instead we had this:

print fmt: "success=%d dependency=%s", REC->success,
    __print_symbolic(REC->dependency, { 0, "NONE" },
     { (1 << TICK_DEP_BIT_POSIX_TIMER), "POSIX_TIMER" },
     { (1 << TICK_DEP_BIT_PERF_EVENTS), "PERF_EVENTS" },
     { (1 << TICK_DEP_BIT_SCHED), "SCHED" },
     { (1 << TICK_DEP_BIT_CLOCK_UNSTABLE), "CLOCK_UNSTABLE" })

User space tools have no idea how to parse "TICK_DEP_BIT_SCHED" or the other
symbols used to do the bit shifting. The reason is that the conversion was
done with using the TICK_DEP_MASK_* symbols which are just macros that
convert to the BIT shift itself (with the exception of NONE, which was
converted properly, because it doesn't use bits, and is defined as zero).

The TICK_DEP_BIT_* needs to be denoted by TRACE_DEFINE_ENUM() in order to
have this properly converted for user space tools to parse this event.

Cc: stable@vger.kernel.org
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Fixes: e6e6cc22 ("nohz: Use enum code for tick stop failure tracing message")
Reported-by: Luiz Capitulino <lcapitulino@redhat.com>
Tested-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent 7522c03a

include/trace/events/timer.h

+11 −3

Original line number	Diff line number	Diff line
		@@ -330,24 +330,32 @@ TRACE_EVENT(itimer_expire,
		#ifdef CONFIG_NO_HZ_COMMON

		#define TICK_DEP_NAMES \
		tick_dep_name(NONE) \
		tick_dep_mask_name(NONE) \
		tick_dep_name(POSIX_TIMER) \
		tick_dep_name(PERF_EVENTS) \
		tick_dep_name(SCHED) \
		tick_dep_name_end(CLOCK_UNSTABLE)

		#undef tick_dep_name
		#undef tick_dep_mask_name
		#undef tick_dep_name_end

		#define tick_dep_name(sdep) TRACE_DEFINE_ENUM(TICK_DEP_MASK_##sdep);
		#define tick_dep_name_end(sdep) TRACE_DEFINE_ENUM(TICK_DEP_MASK_##sdep);
		/* The MASK will convert to their bits and they need to be processed too */
		#define tick_dep_name(sdep) TRACE_DEFINE_ENUM(TICK_DEP_BIT_##sdep); \
		TRACE_DEFINE_ENUM(TICK_DEP_MASK_##sdep);
		#define tick_dep_name_end(sdep) TRACE_DEFINE_ENUM(TICK_DEP_BIT_##sdep); \
		TRACE_DEFINE_ENUM(TICK_DEP_MASK_##sdep);
		/* NONE only has a mask defined for it */
		#define tick_dep_mask_name(sdep) TRACE_DEFINE_ENUM(TICK_DEP_MASK_##sdep);

		TICK_DEP_NAMES

		#undef tick_dep_name
		#undef tick_dep_mask_name
		#undef tick_dep_name_end

		#define tick_dep_name(sdep) { TICK_DEP_MASK_##sdep, #sdep },
		#define tick_dep_mask_name(sdep) { TICK_DEP_MASK_##sdep, #sdep },
		#define tick_dep_name_end(sdep) { TICK_DEP_MASK_##sdep, #sdep }

		#define show_tick_dep_name(val) \

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