From: David Vrabel <david.vrabel@citrix.com> To: <xen-devel@lists.xen.org> Cc: David Vrabel <david.vrabel@citrix.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, <linux-kernel@vger.kernel.org>, John Stultz <john.stultz@linaro.org>, Thomas Gleixner <tglx@linutronix.de> Subject: [PATCH 3/5] time: indicate that the clock was set in the pvclock gtod notifier chain Date: Thu, 27 Jun 2013 11:35:46 +0100 [thread overview] Message-ID: <1372329348-20841-4-git-send-email-david.vrabel@citrix.com> (raw) In-Reply-To: <1372329348-20841-1-git-send-email-david.vrabel@citrix.com> From: David Vrabel <david.vrabel@citrix.com> If the clock was set (stepped), set the action parameter to functions in the pvclock gtod notifier chain to non-zero. This allows the callee to only do work if the clock was stepped. This will be used on Xen as the synchronization of the Xen wallclock to the control domain's (dom0) system time will be done with this notifier and updating on every timer tick is unnecessary and too expensive. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- include/linux/pvclock_gtod.h | 7 +++++++ kernel/time/timekeeping.c | 30 ++++++++++++++++++------------ 2 files changed, 25 insertions(+), 12 deletions(-) diff --git a/include/linux/pvclock_gtod.h b/include/linux/pvclock_gtod.h index 0ca7582..a71d2db 100644 --- a/include/linux/pvclock_gtod.h +++ b/include/linux/pvclock_gtod.h @@ -3,6 +3,13 @@ #include <linux/notifier.h> +/* + * The pvclock gtod notifier is called when the system time is updated + * and is used to keep guest time synchronized with host time. + * + * The 'action' parameter in the notifier function is false (0), or + * true (non-zero) if system time was stepped. + */ extern int pvclock_gtod_register_notifier(struct notifier_block *nb); extern int pvclock_gtod_unregister_notifier(struct notifier_block *nb); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 7aed2b0..dd1b94d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -28,6 +28,7 @@ #define TK_CLEAR_NTP (1 << 0) #define TK_MIRROR (1 << 1) +#define TK_CLOCK_WAS_SET (1 << 2) static struct timekeeper timekeeper; static DEFINE_RAW_SPINLOCK(timekeeper_lock); @@ -203,9 +204,9 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); -static void update_pvclock_gtod(struct timekeeper *tk) +static void update_pvclock_gtod(struct timekeeper *tk, bool was_set) { - raw_notifier_call_chain(&pvclock_gtod_chain, 0, tk); + raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk); } /** @@ -219,7 +220,7 @@ int pvclock_gtod_register_notifier(struct notifier_block *nb) raw_spin_lock_irqsave(&timekeeper_lock, flags); ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); - update_pvclock_gtod(tk); + update_pvclock_gtod(tk, true); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); return ret; @@ -251,7 +252,7 @@ static void timekeeping_update(struct timekeeper *tk, unsigned action) ntp_clear(); } update_vsyscall(tk); - update_pvclock_gtod(tk); + update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); if (action & TK_MIRROR) memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper)); @@ -511,7 +512,7 @@ int do_settimeofday(const struct timespec *tv) tk_set_xtime(tk, tv); - timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -555,7 +556,7 @@ int timekeeping_inject_offset(struct timespec *ts) tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); error: /* even if we error out, we forwarded the time, so call update */ - timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -636,7 +637,7 @@ static int change_clocksource(void *data) if (old->disable) old->disable(old); } - timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -875,7 +876,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta) __timekeeping_inject_sleeptime(tk, delta); - timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -957,7 +958,7 @@ static void timekeeping_resume(void) tk->cycle_last = clock->cycle_last = cycle_now; tk->ntp_error = 0; timekeeping_suspended = 0; - timekeeping_update(tk, TK_MIRROR); + timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -1239,9 +1240,10 @@ out_adjust: * It also calls into the NTP code to handle leapsecond processing. * */ -static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) +static inline bool accumulate_nsecs_to_secs(struct timekeeper *tk) { u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; + unsigned action = 0; while (tk->xtime_nsec >= nsecps) { int leap; @@ -1264,8 +1266,10 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); clock_was_set_delayed(); + action = TK_CLOCK_WAS_SET; } } + return action; } /** @@ -1350,6 +1354,7 @@ static void update_wall_time(void) struct timekeeper *tk = &shadow_timekeeper; cycle_t offset; int shift = 0, maxshift; + unsigned action; unsigned long flags; raw_spin_lock_irqsave(&timekeeper_lock, flags); @@ -1402,7 +1407,7 @@ static void update_wall_time(void) * Finally, make sure that after the rounding * xtime_nsec isn't larger than NSEC_PER_SEC */ - accumulate_nsecs_to_secs(tk); + action = accumulate_nsecs_to_secs(tk); write_seqcount_begin(&timekeeper_seq); /* Update clock->cycle_last with the new value */ @@ -1418,7 +1423,7 @@ static void update_wall_time(void) * updating. */ memcpy(real_tk, tk, sizeof(*tk)); - timekeeping_update(real_tk, 0); + timekeeping_update(real_tk, action); write_seqcount_end(&timekeeper_seq); out: raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -1680,6 +1685,7 @@ int do_adjtimex(struct timex *txc) if (tai != orig_tai) { __timekeeping_set_tai_offset(tk, tai); + update_pvclock_gtod(tk, true); clock_was_set_delayed(); } write_seqcount_end(&timekeeper_seq); -- 1.7.2.5
WARNING: multiple messages have this Message-ID (diff)
From: David Vrabel <david.vrabel@citrix.com> To: xen-devel@lists.xen.org Cc: linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>, John Stultz <john.stultz@linaro.org>, David Vrabel <david.vrabel@citrix.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Subject: [PATCH 3/5] time: indicate that the clock was set in the pvclock gtod notifier chain Date: Thu, 27 Jun 2013 11:35:46 +0100 [thread overview] Message-ID: <1372329348-20841-4-git-send-email-david.vrabel@citrix.com> (raw) In-Reply-To: <1372329348-20841-1-git-send-email-david.vrabel@citrix.com> From: David Vrabel <david.vrabel@citrix.com> If the clock was set (stepped), set the action parameter to functions in the pvclock gtod notifier chain to non-zero. This allows the callee to only do work if the clock was stepped. This will be used on Xen as the synchronization of the Xen wallclock to the control domain's (dom0) system time will be done with this notifier and updating on every timer tick is unnecessary and too expensive. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- include/linux/pvclock_gtod.h | 7 +++++++ kernel/time/timekeeping.c | 30 ++++++++++++++++++------------ 2 files changed, 25 insertions(+), 12 deletions(-) diff --git a/include/linux/pvclock_gtod.h b/include/linux/pvclock_gtod.h index 0ca7582..a71d2db 100644 --- a/include/linux/pvclock_gtod.h +++ b/include/linux/pvclock_gtod.h @@ -3,6 +3,13 @@ #include <linux/notifier.h> +/* + * The pvclock gtod notifier is called when the system time is updated + * and is used to keep guest time synchronized with host time. + * + * The 'action' parameter in the notifier function is false (0), or + * true (non-zero) if system time was stepped. + */ extern int pvclock_gtod_register_notifier(struct notifier_block *nb); extern int pvclock_gtod_unregister_notifier(struct notifier_block *nb); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 7aed2b0..dd1b94d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -28,6 +28,7 @@ #define TK_CLEAR_NTP (1 << 0) #define TK_MIRROR (1 << 1) +#define TK_CLOCK_WAS_SET (1 << 2) static struct timekeeper timekeeper; static DEFINE_RAW_SPINLOCK(timekeeper_lock); @@ -203,9 +204,9 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); -static void update_pvclock_gtod(struct timekeeper *tk) +static void update_pvclock_gtod(struct timekeeper *tk, bool was_set) { - raw_notifier_call_chain(&pvclock_gtod_chain, 0, tk); + raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk); } /** @@ -219,7 +220,7 @@ int pvclock_gtod_register_notifier(struct notifier_block *nb) raw_spin_lock_irqsave(&timekeeper_lock, flags); ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); - update_pvclock_gtod(tk); + update_pvclock_gtod(tk, true); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); return ret; @@ -251,7 +252,7 @@ static void timekeeping_update(struct timekeeper *tk, unsigned action) ntp_clear(); } update_vsyscall(tk); - update_pvclock_gtod(tk); + update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); if (action & TK_MIRROR) memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper)); @@ -511,7 +512,7 @@ int do_settimeofday(const struct timespec *tv) tk_set_xtime(tk, tv); - timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -555,7 +556,7 @@ int timekeeping_inject_offset(struct timespec *ts) tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); error: /* even if we error out, we forwarded the time, so call update */ - timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -636,7 +637,7 @@ static int change_clocksource(void *data) if (old->disable) old->disable(old); } - timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -875,7 +876,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta) __timekeeping_inject_sleeptime(tk, delta); - timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -957,7 +958,7 @@ static void timekeeping_resume(void) tk->cycle_last = clock->cycle_last = cycle_now; tk->ntp_error = 0; timekeeping_suspended = 0; - timekeeping_update(tk, TK_MIRROR); + timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -1239,9 +1240,10 @@ out_adjust: * It also calls into the NTP code to handle leapsecond processing. * */ -static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) +static inline bool accumulate_nsecs_to_secs(struct timekeeper *tk) { u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; + unsigned action = 0; while (tk->xtime_nsec >= nsecps) { int leap; @@ -1264,8 +1266,10 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); clock_was_set_delayed(); + action = TK_CLOCK_WAS_SET; } } + return action; } /** @@ -1350,6 +1354,7 @@ static void update_wall_time(void) struct timekeeper *tk = &shadow_timekeeper; cycle_t offset; int shift = 0, maxshift; + unsigned action; unsigned long flags; raw_spin_lock_irqsave(&timekeeper_lock, flags); @@ -1402,7 +1407,7 @@ static void update_wall_time(void) * Finally, make sure that after the rounding * xtime_nsec isn't larger than NSEC_PER_SEC */ - accumulate_nsecs_to_secs(tk); + action = accumulate_nsecs_to_secs(tk); write_seqcount_begin(&timekeeper_seq); /* Update clock->cycle_last with the new value */ @@ -1418,7 +1423,7 @@ static void update_wall_time(void) * updating. */ memcpy(real_tk, tk, sizeof(*tk)); - timekeeping_update(real_tk, 0); + timekeeping_update(real_tk, action); write_seqcount_end(&timekeeper_seq); out: raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -1680,6 +1685,7 @@ int do_adjtimex(struct timex *txc) if (tai != orig_tai) { __timekeeping_set_tai_offset(tk, tai); + update_pvclock_gtod(tk, true); clock_was_set_delayed(); } write_seqcount_end(&timekeeper_seq); -- 1.7.2.5
next prev parent reply other threads:[~2013-06-27 10:36 UTC|newest] Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-06-27 10:35 [PATCHv6 0/5] xen: maintain an accurate persistent clock in more cases David Vrabel 2013-06-27 10:35 ` [PATCH 1/5] hrtimers: support resuming with two or more CPUs online (but stopped) David Vrabel 2013-06-27 10:35 ` David Vrabel 2013-06-28 21:18 ` [tip:timers/core] hrtimers: Support " tip-bot for David Vrabel 2013-06-28 21:18 ` tip-bot for David Vrabel 2013-07-05 9:30 ` Artem Savkov 2013-07-05 10:07 ` David Vrabel 2013-07-05 10:07 ` David Vrabel 2013-07-05 10:10 ` Thomas Gleixner 2013-07-05 10:10 ` Thomas Gleixner 2013-07-05 10:25 ` Thomas Gleixner 2013-07-05 10:25 ` Thomas Gleixner 2013-07-05 10:36 ` Thomas Gleixner 2013-07-05 10:36 ` Thomas Gleixner 2013-07-05 10:45 ` Artem Savkov 2013-07-05 10:45 ` Artem Savkov 2013-07-05 13:26 ` Thomas Gleixner 2013-07-05 13:26 ` Thomas Gleixner 2013-07-05 10:38 ` Artem Savkov 2013-07-05 10:38 ` Artem Savkov 2013-07-05 13:46 ` David Vrabel 2013-07-05 13:51 ` Thomas Gleixner 2013-07-05 13:51 ` Thomas Gleixner 2013-07-05 13:46 ` David Vrabel 2013-07-05 10:09 ` Thomas Gleixner 2013-07-05 10:09 ` Thomas Gleixner 2013-07-05 9:30 ` Artem Savkov 2013-06-28 21:18 ` [tip:timers/core] xen: Remove clock_was_set() call in the resume path tip-bot for David Vrabel 2013-06-28 21:18 ` tip-bot for David Vrabel 2013-06-27 10:35 ` [PATCH 2/5] time: pass flags instead of multiple bools to timekeeping_update() David Vrabel 2013-06-27 17:39 ` John Stultz 2013-06-27 17:39 ` John Stultz 2013-06-28 21:18 ` [tip:timers/core] timekeeping: Pass " tip-bot for David Vrabel 2013-06-28 21:18 ` tip-bot for David Vrabel 2013-06-27 10:35 ` [PATCH 2/5] time: pass " David Vrabel 2013-06-27 10:35 ` David Vrabel [this message] 2013-06-27 10:35 ` [PATCH 3/5] time: indicate that the clock was set in the pvclock gtod notifier chain David Vrabel 2013-06-27 17:37 ` John Stultz 2013-06-27 17:37 ` John Stultz 2013-06-28 10:20 ` David Vrabel 2013-06-28 10:20 ` David Vrabel 2013-06-28 21:19 ` [tip:timers/core] timekeeping: Indicate that clock was set in the pvclock gtod notifier tip-bot for David Vrabel 2013-06-28 21:19 ` tip-bot for David Vrabel 2013-06-27 10:35 ` [PATCH 4/5] x86/xen: sync the wallclock when the system time is set David Vrabel 2013-06-28 21:19 ` [tip:timers/core] x86: xen: Sync " tip-bot for David Vrabel 2013-06-28 21:19 ` tip-bot for David Vrabel 2013-06-27 10:35 ` [PATCH 4/5] x86/xen: sync " David Vrabel 2013-06-27 10:35 ` [PATCH 5/5] x86/xen: sync the CMOS RTC as well as the Xen wallclock David Vrabel 2013-06-28 15:38 ` Thomas Gleixner 2013-06-28 15:49 ` David Vrabel 2013-06-28 15:49 ` David Vrabel 2013-06-28 16:09 ` Thomas Gleixner 2013-06-28 16:51 ` David Vrabel 2013-06-28 20:41 ` Thomas Gleixner 2013-06-28 20:41 ` Thomas Gleixner 2013-06-28 16:51 ` David Vrabel 2013-06-28 16:09 ` Thomas Gleixner 2013-06-28 15:38 ` Thomas Gleixner 2013-06-28 21:19 ` [tip:timers/core] x86: xen: Sync " tip-bot for David Vrabel 2013-06-28 21:19 ` tip-bot for David Vrabel 2013-06-27 10:35 ` [PATCH 5/5] x86/xen: sync " David Vrabel 2013-06-28 13:14 ` [PATCHv6 0/5] xen: maintain an accurate persistent clock in more cases Thomas Gleixner 2013-06-28 13:14 ` Thomas Gleixner 2013-06-28 15:01 ` Konrad Rzeszutek Wilk 2013-06-28 15:01 ` Konrad Rzeszutek Wilk 2013-06-28 15:12 ` Thomas Gleixner 2013-06-28 15:12 ` Thomas Gleixner 2013-06-28 16:19 ` Konrad Rzeszutek Wilk 2013-06-28 16:19 ` Konrad Rzeszutek Wilk 2013-06-28 18:58 ` Thomas Gleixner 2013-06-28 18:58 ` Thomas Gleixner
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