Conflate boot and mono trace clocks and document the new behaviour. Signed-off-by: Thomas Gleixner Cc: Steven Rostedt --- 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 };