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authorThomas Gleixner <tglx@linutronix.de>2018-03-01 19:33:32 +0300
committerIngo Molnar <mingo@kernel.org>2018-03-13 09:34:21 +0300
commit72199320d49dbafa1a99f94f1cd60dc90035c154 (patch)
treeca7a4e1337c8f56b404e4d7af0de73115fee88ce /kernel/time/timekeeping.c
parent78b98e3c5a66d569a53b8f57b6a698f912794a43 (diff)
downloadlinux-72199320d49dbafa1a99f94f1cd60dc90035c154.tar.xz
timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock
The planned change to unify the behaviour of the MONOTONIC and BOOTTIME clocks vs. suspend removes the ability to retrieve the active non-suspended time of a system. Provide a new CLOCK_MONOTONIC_ACTIVE clock which returns the active non-suspended time of the system via clock_gettime(). This preserves the old behaviour of CLOCK_MONOTONIC before the BOOTTIME/MONOTONIC unification. This new clock also allows applications to detect programmatically that the MONOTONIC and BOOTTIME clocks are identical. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Easton <kevin@guarana.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20180301165149.965235774@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/time/timekeeping.c')
-rw-r--r--kernel/time/timekeeping.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e11760121cb2..a2b7f583e64e 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -139,6 +139,9 @@ static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm)
static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
{
tk->offs_boot = ktime_add(tk->offs_boot, delta);
+
+ /* Accumulate time spent in suspend */
+ tk->time_suspended += delta;
}
/*
@@ -887,6 +890,39 @@ void ktime_get_ts64(struct timespec64 *ts)
EXPORT_SYMBOL_GPL(ktime_get_ts64);
/**
+ * ktime_get_active_ts64 - Get the active non-suspended monotonic clock
+ * @ts: pointer to timespec variable
+ *
+ * The function calculates the monotonic clock from the realtime clock and
+ * the wall_to_monotonic offset, subtracts the accumulated suspend time and
+ * stores the result in normalized timespec64 format in the variable
+ * pointed to by @ts.
+ */
+void ktime_get_active_ts64(struct timespec64 *ts)
+{
+ struct timekeeper *tk = &tk_core.timekeeper;
+ struct timespec64 tomono, tsusp;
+ u64 nsec, nssusp;
+ unsigned int seq;
+
+ WARN_ON(timekeeping_suspended);
+
+ do {
+ seq = read_seqcount_begin(&tk_core.seq);
+ ts->tv_sec = tk->xtime_sec;
+ nsec = timekeeping_get_ns(&tk->tkr_mono);
+ tomono = tk->wall_to_monotonic;
+ nssusp = tk->time_suspended;
+ } while (read_seqcount_retry(&tk_core.seq, seq));
+
+ ts->tv_sec += tomono.tv_sec;
+ ts->tv_nsec = 0;
+ timespec64_add_ns(ts, nsec + tomono.tv_nsec);
+ tsusp = ns_to_timespec64(nssusp);
+ *ts = timespec64_sub(*ts, tsusp);
+}
+
+/**
* ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC
*
* Returns the seconds portion of CLOCK_MONOTONIC with a single non