Conflate boot and mono trace clocks and document the new behaviour.
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Cc: Steven Rostedt <rost...@goodmis.org>
---
Documentation/trace/ftrace.txt | 14 +++-----------
include/linux/timekeeping.h | 6 ------
kernel/trace/trace.c | 2 +-
3 files changed, 4 insertions(+), 18 deletions(-)
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -449,17 +449,9 @@ After mounting tracefs you will have acc
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.
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -113,12 +113,6 @@ extern u64 ktime_get_mono_fast_ns(void);
extern u64 ktime_get_raw_fast_ns(void);
extern u64 ktime_get_real_fast_ns(void);
-/* Clock BOOTTIME compatibility wrappers */
-static inline u64 ktime_get_boot_fast_ns(void)
-{
- return ktime_get_mono_fast_ns();
-}
-
/*
* timespec64 interfaces utilizing the ktime based ones
*/
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1164,7 +1164,7 @@ static struct {
{ trace_clock, "perf", 1 },
{ ktime_get_mono_fast_ns, "mono", 1 },
{ ktime_get_raw_fast_ns, "mono_raw", 1 },
- { ktime_get_boot_fast_ns, "boot", 1 },
+ { ktime_get_mono_fast_ns, "boot", 1 },
ARCH_TRACE_CLOCKS
};
