From 72199320d49dbafa1a99f94f1cd60dc90035c154 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 1 Mar 2018 17:33:32 +0100 Subject: [PATCH] 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 Cc: Dmitry Torokhov Cc: John Stultz Cc: Jonathan Corbet Cc: Kevin Easton Cc: Linus Torvalds Cc: Mark Salyzyn Cc: Michael Kerrisk Cc: Peter Zijlstra Cc: Petr Mladek Cc: Prarit Bhargava Cc: Sergey Senozhatsky Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20180301165149.965235774@linutronix.de Signed-off-by: Ingo Molnar --- include/linux/timekeeper_internal.h | 2 ++ include/linux/timekeeping.h | 1 + include/uapi/linux/time.h | 1 + kernel/time/posix-stubs.c | 2 ++ kernel/time/posix-timers.c | 13 +++++++++++ kernel/time/timekeeping.c | 36 +++++++++++++++++++++++++++++ 6 files changed, 55 insertions(+) diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index 7acb953298a7..4b3dca173e89 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -52,6 +52,7 @@ struct tk_read_base { * @offs_real: Offset clock monotonic -> clock realtime * @offs_boot: Offset clock monotonic -> clock boottime * @offs_tai: Offset clock monotonic -> clock tai + * @time_suspended: Accumulated suspend time * @tai_offset: The current UTC to TAI offset in seconds * @clock_was_set_seq: The sequence number of clock was set events * @cs_was_changed_seq: The sequence number of clocksource change events @@ -94,6 +95,7 @@ struct timekeeper { ktime_t offs_real; ktime_t offs_boot; ktime_t offs_tai; + ktime_t time_suspended; s32 tai_offset; unsigned int clock_was_set_seq; u8 cs_was_changed_seq; diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index b17bcce58bc4..440b1935d3a5 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -32,6 +32,7 @@ extern void getrawmonotonic64(struct timespec64 *ts); extern void ktime_get_ts64(struct timespec64 *ts); extern time64_t ktime_get_seconds(void); extern time64_t ktime_get_real_seconds(void); +extern void ktime_get_active_ts64(struct timespec64 *ts); extern int __getnstimeofday64(struct timespec64 *tv); extern void getnstimeofday64(struct timespec64 *tv); diff --git a/include/uapi/linux/time.h b/include/uapi/linux/time.h index 53f8dd84beb5..61a187df8da2 100644 --- a/include/uapi/linux/time.h +++ b/include/uapi/linux/time.h @@ -61,6 +61,7 @@ struct itimerval { */ #define CLOCK_SGI_CYCLE 10 #define CLOCK_TAI 11 +#define CLOCK_MONOTONIC_ACTIVE 12 #define MAX_CLOCKS 16 #define CLOCKS_MASK (CLOCK_REALTIME | CLOCK_MONOTONIC) diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c index b258bee13b02..6259dbc0191a 100644 --- a/kernel/time/posix-stubs.c +++ b/kernel/time/posix-stubs.c @@ -73,6 +73,8 @@ int do_clock_gettime(clockid_t which_clock, struct timespec64 *tp) case CLOCK_BOOTTIME: get_monotonic_boottime64(tp); break; + case CLOCK_MONOTONIC_ACTIVE: + ktime_get_active_ts64(tp); default: return -EINVAL; } diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 75043046914e..556fe02a47a4 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -263,6 +263,13 @@ static int posix_get_tai(clockid_t which_clock, struct timespec64 *tp) return 0; } +static int posix_get_monotonic_active(clockid_t which_clock, + struct timespec64 *tp) +{ + ktime_get_active_ts64(tp); + return 0; +} + static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp) { tp->tv_sec = 0; @@ -1330,6 +1337,11 @@ static const struct k_clock clock_boottime = { .timer_arm = common_hrtimer_arm, }; +static const struct k_clock clock_monotonic_active = { + .clock_getres = posix_get_hrtimer_res, + .clock_get = posix_get_monotonic_active, +}; + static const struct k_clock * const posix_clocks[] = { [CLOCK_REALTIME] = &clock_realtime, [CLOCK_MONOTONIC] = &clock_monotonic, @@ -1342,6 +1354,7 @@ static const struct k_clock * const posix_clocks[] = { [CLOCK_REALTIME_ALARM] = &alarm_clock, [CLOCK_BOOTTIME_ALARM] = &alarm_clock, [CLOCK_TAI] = &clock_tai, + [CLOCK_MONOTONIC_ACTIVE] = &clock_monotonic_active, }; static const struct k_clock *clockid_to_kclock(const clockid_t id) 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; } /* @@ -886,6 +889,39 @@ 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 * -- 2.30.2