[for-next][PATCH 04/18] tracing: Mention trace_clock=global when warning about unstable clocks

From: Steven Rostedt
Date: Fri Apr 06 2018 - 09:05:53 EST


From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>

Mention the alternative of adding trace_clock=global to the kernel
command line when we detect that we've used an unstable clock across a
suspend/resume cycle.

Link: http://lkml.kernel.org/r/20180330150132.16903-2-chris@xxxxxxxxxxxxxxxxxx

Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/ring_buffer.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index a2fd3893cc02..515be03e3009 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2731,7 +2731,8 @@ rb_handle_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
sched_clock_stable() ? "" :
"If you just came from a suspend/resume,\n"
"please switch to the trace global clock:\n"
- " echo global > /sys/kernel/debug/tracing/trace_clock\n");
+ " echo global > /sys/kernel/debug/tracing/trace_clock\n"
+ "or add trace_clock=global to the kernel command line\n");
info->add_timestamp = 1;
}

--
2.15.1