Revert commits
92af4dcb4e1c ("tracing: Unify the "boot" and "mono" tracing clocks")
127bfa5f4342 ("hrtimer: Unify MONOTONIC and BOOTTIME clock behavior")
7250a4047aa6 ("posix-timers: Unify MONOTONIC and BOOTTIME clock behavior")
d6c7270e913d ("timekeeping: Remove boot time specific code")
f2d6fdbfd238 ("Input: Evdev - unify MONOTONIC and BOOTTIME clock behavior")
d6ed449afdb3 ("timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock")
72199320d49d ("timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock")
As stated in the pull request for the unification of CLOCK_MONOTONIC and
CLOCK_BOOTTIME, it was clear that we might have to revert the change.
As reported by several folks systemd and other applications rely on the
documented behaviour of CLOCK_MONOTONIC on Linux and break with the above
changes. After resume daemons time out and other timeout related issues are
observed. Rafael compiled this list:
* systemd kills daemons on resume, after >WatchdogSec seconds
of suspending (Genki Sky). [Verified that that's because systemd uses
CLOCK_MONOTONIC and expects it to not include the suspend time.]
* systemd-journald misbehaves after resume:
systemd-journald[7266]: File /var/log/journal/
016627c3c4784cd4812d4b7e96a34226/system.journal
corrupted or uncleanly shut down, renaming and replacing.
(Mike Galbraith).
* NetworkManager reports "networking disabled" and networking is broken
after resume 50% of the time (Pavel). [May be because of systemd.]
* MATE desktop dims the display and starts the screensaver right after
system resume (Pavel).
* Full system hang during resume (me). [May be due to systemd or NM or both.]
That happens on debian and open suse systems.
It's sad, that these problems were neither catched in -next nor by those
folks who expressed interest in this change.
Reported-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Reported-by: Genki Sky <sky@genki.is>,
Reported-by: Pavel Machek <pavel@ucw.cz>
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>
and ticks at the same rate as the hardware clocksource.
boot:
- Same as mono. Used to be a separate clock which accounted
- for the time spent in suspend while CLOCK_MONOTONIC did
- not.
+ 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.
To set a clock, simply echo the clock name into this file::
enum evdev_clock_type {
EV_CLK_REAL = 0,
EV_CLK_MONO,
+ EV_CLK_BOOT,
EV_CLK_MAX
};
case CLOCK_REALTIME:
clk_type = EV_CLK_REAL;
break;
- case CLOCK_BOOTTIME:
case CLOCK_MONOTONIC:
clk_type = EV_CLK_MONO;
break;
+ case CLOCK_BOOTTIME:
+ clk_type = EV_CLK_BOOT;
+ break;
default:
return -EINVAL;
}
ev_time[EV_CLK_MONO] = ktime_get();
ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
+ ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
+ TK_OFFS_BOOT);
rcu_read_lock();
enum hrtimer_base_type {
HRTIMER_BASE_MONOTONIC,
HRTIMER_BASE_REALTIME,
+ HRTIMER_BASE_BOOTTIME,
HRTIMER_BASE_TAI,
HRTIMER_BASE_MONOTONIC_SOFT,
HRTIMER_BASE_REALTIME_SOFT,
+ HRTIMER_BASE_BOOTTIME_SOFT,
HRTIMER_BASE_TAI_SOFT,
HRTIMER_MAX_CLOCK_BASES,
};
* @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
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;
extern time64_t ktime_get_seconds(void);
extern time64_t __ktime_get_real_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);
extern void getboottime64(struct timespec64 *ts);
-#define ktime_get_real_ts64(ts) getnstimeofday64(ts)
-
-/* Clock BOOTTIME compatibility wrappers */
-static inline void get_monotonic_boottime64(struct timespec64 *ts)
-{
- ktime_get_ts64(ts);
-}
+#define ktime_get_real_ts64(ts) getnstimeofday64(ts)
/*
* ktime_t based interfaces
*/
+
enum tk_offsets {
TK_OFFS_REAL,
+ TK_OFFS_BOOT,
TK_OFFS_TAI,
TK_OFFS_MAX,
};
extern ktime_t ktime_get_raw(void);
extern u32 ktime_get_resolution_ns(void);
-/* Clock BOOTTIME compatibility wrappers */
-static inline ktime_t ktime_get_boottime(void) { return ktime_get(); }
-static inline u64 ktime_get_boot_ns(void) { return ktime_get(); }
-
/**
* ktime_get_real - get the real (wall-) time in ktime_t format
*/
return ktime_get_with_offset(TK_OFFS_REAL);
}
+/**
+ * ktime_get_boottime - Returns monotonic time since boot in ktime_t format
+ *
+ * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the
+ * time spent in suspend.
+ */
+static inline ktime_t ktime_get_boottime(void)
+{
+ return ktime_get_with_offset(TK_OFFS_BOOT);
+}
+
/**
* ktime_get_clocktai - Returns the TAI time of day in ktime_t format
*/
return ktime_to_ns(ktime_get_real());
}
+static inline u64 ktime_get_boot_ns(void)
+{
+ return ktime_to_ns(ktime_get_boottime());
+}
+
static inline u64 ktime_get_tai_ns(void)
{
return ktime_to_ns(ktime_get_clocktai());
extern u64 ktime_get_mono_fast_ns(void);
extern u64 ktime_get_raw_fast_ns(void);
+extern u64 ktime_get_boot_fast_ns(void);
extern u64 ktime_get_real_fast_ns(void);
/*
* timespec64 interfaces utilizing the ktime based ones
*/
+static inline void get_monotonic_boottime64(struct timespec64 *ts)
+{
+ *ts = ktime_to_timespec64(ktime_get_boottime());
+}
+
static inline void timekeeping_clocktai64(struct timespec64 *ts)
{
*ts = ktime_to_timespec64(ktime_get_clocktai());
*/
#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)
.clockid = CLOCK_REALTIME,
.get_time = &ktime_get_real,
},
+ {
+ .index = HRTIMER_BASE_BOOTTIME,
+ .clockid = CLOCK_BOOTTIME,
+ .get_time = &ktime_get_boottime,
+ },
{
.index = HRTIMER_BASE_TAI,
.clockid = CLOCK_TAI,
.clockid = CLOCK_REALTIME,
.get_time = &ktime_get_real,
},
+ {
+ .index = HRTIMER_BASE_BOOTTIME_SOFT,
+ .clockid = CLOCK_BOOTTIME,
+ .get_time = &ktime_get_boottime,
+ },
{
.index = HRTIMER_BASE_TAI_SOFT,
.clockid = CLOCK_TAI,
[CLOCK_REALTIME] = HRTIMER_BASE_REALTIME,
[CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC,
- [CLOCK_BOOTTIME] = HRTIMER_BASE_MONOTONIC,
+ [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME,
[CLOCK_TAI] = HRTIMER_BASE_TAI,
};
static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
{
ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset;
+ ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset;
ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset;
ktime_t now = ktime_get_update_offsets_now(&base->clock_was_set_seq,
- offs_real, offs_tai);
+ offs_real, offs_boot, offs_tai);
base->clock_base[HRTIMER_BASE_REALTIME_SOFT].offset = *offs_real;
+ base->clock_base[HRTIMER_BASE_BOOTTIME_SOFT].offset = *offs_boot;
base->clock_base[HRTIMER_BASE_TAI_SOFT].offset = *offs_tai;
return now;
case CLOCK_BOOTTIME:
get_monotonic_boottime64(tp);
break;
- case CLOCK_MONOTONIC_ACTIVE:
- ktime_get_active_ts64(tp);
default:
return -EINVAL;
}
return 0;
}
-static int posix_get_tai(clockid_t which_clock, struct timespec64 *tp)
+static int posix_get_boottime(const clockid_t which_clock, struct timespec64 *tp)
{
- timekeeping_clocktai64(tp);
+ get_monotonic_boottime64(tp);
return 0;
}
-static int posix_get_monotonic_active(clockid_t which_clock,
- struct timespec64 *tp)
+static int posix_get_tai(clockid_t which_clock, struct timespec64 *tp)
{
- ktime_get_active_ts64(tp);
+ timekeeping_clocktai64(tp);
return 0;
}
.timer_arm = common_hrtimer_arm,
};
-static const struct k_clock clock_monotonic_active = {
+static const struct k_clock clock_boottime = {
.clock_getres = posix_get_hrtimer_res,
- .clock_get = posix_get_monotonic_active,
+ .clock_get = posix_get_boottime,
+ .nsleep = common_nsleep,
+ .timer_create = common_timer_create,
+ .timer_set = common_timer_set,
+ .timer_get = common_timer_get,
+ .timer_del = common_timer_del,
+ .timer_rearm = common_hrtimer_rearm,
+ .timer_forward = common_hrtimer_forward,
+ .timer_remaining = common_hrtimer_remaining,
+ .timer_try_to_cancel = common_hrtimer_try_to_cancel,
+ .timer_arm = common_hrtimer_arm,
};
static const struct k_clock * const posix_clocks[] = {
[CLOCK_MONOTONIC_RAW] = &clock_monotonic_raw,
[CLOCK_REALTIME_COARSE] = &clock_realtime_coarse,
[CLOCK_MONOTONIC_COARSE] = &clock_monotonic_coarse,
- [CLOCK_BOOTTIME] = &clock_monotonic,
+ [CLOCK_BOOTTIME] = &clock_boottime,
[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)
clockevents_shutdown(td->evtdev);
}
-static void tick_forward_next_period(void)
-{
- ktime_t delta, now = ktime_get();
- u64 n;
-
- delta = ktime_sub(now, tick_next_period);
- n = ktime_divns(delta, tick_period);
- tick_next_period += n * tick_period;
- if (tick_next_period < now)
- tick_next_period += tick_period;
- tick_sched_forward_next_period();
-}
-
/**
* tick_resume_local - Resume the local tick device
*
struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
bool broadcast = tick_resume_check_broadcast();
- tick_forward_next_period();
-
clockevents_tick_resume(td->evtdev);
if (!broadcast) {
if (td->mode == TICKDEV_MODE_PERIODIC)
static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
#endif /* !(BROADCAST && ONESHOT) */
-#if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS)
-extern void tick_sched_forward_next_period(void);
-#else
-static inline void tick_sched_forward_next_period(void) { }
-#endif
-
/* NO_HZ_FULL internal */
#ifdef CONFIG_NO_HZ_FULL
extern void tick_nohz_init(void);
*/
static ktime_t last_jiffies_update;
-/*
- * Called after resume. Make sure that jiffies are not fast forwarded due to
- * clock monotonic being forwarded by the suspended time.
- */
-void tick_sched_forward_next_period(void)
-{
- last_jiffies_update = tick_next_period;
-}
-
/*
* Must be called with interrupts disabled !
*/
static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
{
- /* Update both bases so mono and raw stay coupled. */
- tk->tkr_mono.base += delta;
- tk->tkr_raw.base += delta;
-
- /* Accumulate time spent in suspend */
- tk->time_suspended += delta;
+ tk->offs_boot = ktime_add(tk->offs_boot, delta);
}
/*
}
EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
+/**
+ * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock.
+ *
+ * To keep it NMI safe since we're accessing from tracing, we're not using a
+ * separate timekeeper with updates to monotonic clock and boot offset
+ * protected with seqlocks. This has the following minor side effects:
+ *
+ * (1) Its possible that a timestamp be taken after the boot offset is updated
+ * but before the timekeeper is updated. If this happens, the new boot offset
+ * is added to the old timekeeping making the clock appear to update slightly
+ * earlier:
+ * CPU 0 CPU 1
+ * timekeeping_inject_sleeptime64()
+ * __timekeeping_inject_sleeptime(tk, delta);
+ * timestamp();
+ * timekeeping_update(tk, TK_CLEAR_NTP...);
+ *
+ * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
+ * partially updated. Since the tk->offs_boot update is a rare event, this
+ * should be a rare occurrence which postprocessing should be able to handle.
+ */
+u64 notrace ktime_get_boot_fast_ns(void)
+{
+ struct timekeeper *tk = &tk_core.timekeeper;
+
+ return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot));
+}
+EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns);
+
+
/*
* See comment for __ktime_get_fast_ns() vs. timestamp ordering
*/
static ktime_t *offsets[TK_OFFS_MAX] = {
[TK_OFFS_REAL] = &tk_core.timekeeper.offs_real,
+ [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot,
[TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai,
};
}
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
*
return;
}
tk_xtime_add(tk, delta);
+ tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta));
tk_update_sleep_time(tk, timespec64_to_ktime(*delta));
tk_debug_account_sleep_time(delta);
}
void getboottime64(struct timespec64 *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
- ktime_t t = ktime_sub(tk->offs_real, tk->time_suspended);
+ ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot);
*ts = ktime_to_timespec64(t);
}
* ktime_get_update_offsets_now - hrtimer helper
* @cwsseq: pointer to check and store the clock was set sequence number
* @offs_real: pointer to storage for monotonic -> realtime offset
+ * @offs_boot: pointer to storage for monotonic -> boottime offset
* @offs_tai: pointer to storage for monotonic -> clock tai offset
*
* Returns current monotonic time and updates the offsets if the
* Called from hrtimer_interrupt() or retrigger_next_event()
*/
ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
- ktime_t *offs_tai)
+ ktime_t *offs_boot, ktime_t *offs_tai)
{
struct timekeeper *tk = &tk_core.timekeeper;
unsigned int seq;
if (*cwsseq != tk->clock_was_set_seq) {
*cwsseq = tk->clock_was_set_seq;
*offs_real = tk->offs_real;
+ *offs_boot = tk->offs_boot;
*offs_tai = tk->offs_tai;
}
*/
extern ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq,
ktime_t *offs_real,
+ ktime_t *offs_boot,
ktime_t *offs_tai);
extern int timekeeping_valid_for_hres(void);
{ trace_clock, "perf", 1 },
{ ktime_get_mono_fast_ns, "mono", 1 },
{ ktime_get_raw_fast_ns, "mono_raw", 1 },
- { ktime_get_mono_fast_ns, "boot", 1 },
+ { ktime_get_boot_fast_ns, "boot", 1 },
ARCH_TRACE_CLOCKS
};
projects / kernel.git / commitdiff