summaryrefslogtreecommitdiffstats
path: root/Documentation/trace/ftrace.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/trace/ftrace.rst')
-rw-r--r--Documentation/trace/ftrace.rst22
1 files changed, 7 insertions, 15 deletions
diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst
index 0bc33ad4a3f9..fdf5fb54a04c 100644
--- a/Documentation/trace/ftrace.rst
+++ b/Documentation/trace/ftrace.rst
@@ -461,21 +461,13 @@ of ftrace. Here is a list of some of the key files:
and ticks at the same rate as the hardware clocksource.
boot:
- This is the boot clock (CLOCK_BOOTTIME) and is based on the
- fast monotonic clock, but also accounts for time spent in
- suspend. Since the clock access is designed for use in
- tracing in the suspend path, some side effects are possible
- if clock is accessed after the suspend time is accounted before
- the fast mono clock is updated. In this case, the clock update
- appears to happen slightly sooner than it normally would have.
- Also on 32-bit systems, it's possible that the 64-bit boot offset
- sees a partial update. These effects are rare and post
- processing should be able to handle them. See comments in the
- ktime_get_boot_fast_ns() function for more information.
-
- To set a clock, simply echo the clock name into this file::
-
- echo global > trace_clock
+ Same as mono. Used to be a separate clock which accounted
+ for the time spent in suspend while CLOCK_MONOTONIC did
+ not.
+
+ To set a clock, simply echo the clock name into this file::
+
+ # echo global > trace_clock
trace_marker: