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-rw-r--r--Documentation/trace/ftrace.txt14
1 files changed, 3 insertions, 11 deletions
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index d4601df6e72e..bf89f98bfdb9 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -449,17 +449,9 @@ of ftrace. Here is a list of some of the key files:
which is montonic but is not subject to any rate adjustments
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.
+ boot: 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.