From ba919d1caa2e624eb8c6cae1f2ce0a253e697d45 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2013 20:31:44 +0000 Subject: clocksource: Let timekeeping_notify return success/error timekeeping_notify() can fail due cs->enable() failure. Though the caller does not notice and happily keeps the wrong clocksource as the current one. Let the caller know about failure, so the current clocksource will be shown correctly in sysfs. Signed-off-by: Thomas Gleixner Acked-by: John Stultz Cc: Magnus Damm Link: http://lkml.kernel.org/r/20130425143435.696321912@linutronix.de Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 98cd470bbe49..da6e10c7a378 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -648,14 +648,15 @@ static int change_clocksource(void *data) * This function is called from clocksource.c after a new, better clock * source has been registered. The caller holds the clocksource_mutex. */ -void timekeeping_notify(struct clocksource *clock) +int timekeeping_notify(struct clocksource *clock) { struct timekeeper *tk = &timekeeper; if (tk->clock == clock) - return; + return 0; stop_machine(change_clocksource, clock, NULL); tick_clock_notify(); + return tk->clock == clock ? 0 : -1; } /** -- cgit From 09ac369c825d9d593404306d59062d854b321e9b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 25 Apr 2013 20:31:44 +0000 Subject: clocksource: Add module refcount Add a module refcount, so the current clocksource cannot be removed unconditionally. Signed-off-by: Thomas Gleixner Cc: John Stultz Cc: Magnus Damm Link: http://lkml.kernel.org/r/20130425143435.762417789@linutronix.de Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index da6e10c7a378..933efa4071c3 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -627,11 +627,20 @@ static int change_clocksource(void *data) write_seqcount_begin(&timekeeper_seq); timekeeping_forward_now(tk); - if (!new->enable || new->enable(new) == 0) { - old = tk->clock; - tk_setup_internals(tk, new); - if (old->disable) - old->disable(old); + /* + * If the cs is in module, get a module reference. Succeeds + * for built-in code (owner == NULL) as well. + */ + if (try_module_get(new->owner)) { + if (!new->enable || new->enable(new) == 0) { + old = tk->clock; + tk_setup_internals(tk, new); + if (old->disable) + old->disable(old); + module_put(old->owner); + } else { + module_put(new->owner); + } } timekeeping_update(tk, true, true); -- cgit From 5c83545f24ab3dd67e0ae0e2b795fea750f08c34 Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Tue, 21 May 2013 22:32:14 -0700 Subject: power: Add option to log time spent in suspend Below is a patch from android kernel that maintains a histogram of suspend times. Please review and provide feedback. Statistices on the time spent in suspend are kept in /sys/kernel/debug/sleep_time. Cc: Android Kernel Team Cc: Colin Cross Cc: Todd Poynor Cc: San Mehat Cc: Benoit Goby Cc: John Stultz Cc: Thomas Gleixner Signed-off-by: Colin Cross Signed-off-by: Todd Poynor [zoran.markovic@linaro.org: Re-formatted suspend time table to better fit expected values. Moved accounting of suspend time into timekeeping core. Removed CONFIG_SUSPEND_TIME flag and made the feature conditional on CONFIG_DEBUG_FS. Changed the file name to sleep_time to better fit terminology in timekeeping core. Changed seq_printf to seq_puts. Tweaked commit message] Signed-off-by: Zoran Markovic Signed-off-by: John Stultz --- kernel/time/timekeeping.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 933efa4071c3..838fc0777b68 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -25,6 +25,7 @@ #include "tick-internal.h" #include "ntp_internal.h" +#include "timekeeping_internal.h" static struct timekeeper timekeeper; static DEFINE_RAW_SPINLOCK(timekeeper_lock); @@ -851,6 +852,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk, tk_xtime_add(tk, delta); tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta)); tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta)); + tk_debug_account_sleep_time(delta); } /** -- cgit From 04397fe94ad65289884b9862b6a0c722ececaadf Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Thu, 27 Jun 2013 11:35:45 +0100 Subject: timekeeping: Pass flags instead of multiple bools to timekeeping_update() Instead of passing multiple bools to timekeeping_updated(), define flags and use a single 'action' parameter. It is then more obvious what each timekeeping_update() call does. Signed-off-by: David Vrabel Cc: Konrad Rzeszutek Wilk Cc: John Stultz Cc: Link: http://lkml.kernel.org/r/1372329348-20841-3-git-send-email-david.vrabel@citrix.com Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 838fc0777b68..d8b23a929e66 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -27,6 +27,9 @@ #include "ntp_internal.h" #include "timekeeping_internal.h" +#define TK_CLEAR_NTP (1 << 0) +#define TK_MIRROR (1 << 1) + static struct timekeeper timekeeper; static DEFINE_RAW_SPINLOCK(timekeeper_lock); static seqcount_t timekeeper_seq; @@ -242,16 +245,16 @@ int pvclock_gtod_unregister_notifier(struct notifier_block *nb) EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); /* must hold timekeeper_lock */ -static void timekeeping_update(struct timekeeper *tk, bool clearntp, bool mirror) +static void timekeeping_update(struct timekeeper *tk, unsigned int action) { - if (clearntp) { + if (action & TK_CLEAR_NTP) { tk->ntp_error = 0; ntp_clear(); } update_vsyscall(tk); update_pvclock_gtod(tk); - if (mirror) + if (action & TK_MIRROR) memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper)); } @@ -509,7 +512,7 @@ int do_settimeofday(const struct timespec *tv) tk_set_xtime(tk, tv); - timekeeping_update(tk, true, true); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -553,7 +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, true, true); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -643,7 +646,7 @@ static int change_clocksource(void *data) module_put(new->owner); } } - timekeeping_update(tk, true, true); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -884,7 +887,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta) __timekeeping_inject_sleeptime(tk, delta); - timekeeping_update(tk, true, true); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -966,7 +969,7 @@ static void timekeeping_resume(void) tk->cycle_last = clock->cycle_last = cycle_now; tk->ntp_error = 0; timekeeping_suspended = 0; - timekeeping_update(tk, false, true); + timekeeping_update(tk, TK_MIRROR); write_seqcount_end(&timekeeper_seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); @@ -1419,7 +1422,7 @@ static void update_wall_time(void) * updating. */ memcpy(real_tk, tk, sizeof(*tk)); - timekeeping_update(real_tk, false, false); + timekeeping_update(real_tk, 0); write_seqcount_end(&timekeeper_seq); out: raw_spin_unlock_irqrestore(&timekeeper_lock, flags); -- cgit From 780427f0e113b4c77dfff4d258c05a902cdb0eb9 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Thu, 27 Jun 2013 11:35:46 +0100 Subject: timekeeping: Indicate that clock was set in the pvclock gtod notifier 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 Cc: Konrad Rzeszutek Wilk Cc: John Stultz Cc: Link: http://lkml.kernel.org/r/1372329348-20841-4-git-send-email-david.vrabel@citrix.com Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index d8b23a929e66..846d0a1f235e 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -29,6 +29,7 @@ #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); @@ -204,9 +205,9 @@ 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); } /** @@ -220,7 +221,7 @@ 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; @@ -252,7 +253,7 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int 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)); @@ -512,7 +513,7 @@ 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); @@ -556,7 +557,7 @@ 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); @@ -646,7 +647,7 @@ static int change_clocksource(void *data) module_put(new->owner); } } - 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); @@ -887,7 +888,7 @@ 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); @@ -969,7 +970,7 @@ 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); @@ -1243,9 +1244,10 @@ 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 unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) { u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; + unsigned int action = 0; while (tk->xtime_nsec >= nsecps) { int leap; @@ -1268,8 +1270,10 @@ 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; } /** @@ -1354,6 +1358,7 @@ static void update_wall_time(void) struct timekeeper *tk = &shadow_timekeeper; cycle_t offset; int shift = 0, maxshift; + unsigned int action; unsigned long flags; raw_spin_lock_irqsave(&timekeeper_lock, flags); @@ -1406,7 +1411,7 @@ 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 */ @@ -1422,7 +1427,7 @@ 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); @@ -1684,6 +1689,7 @@ 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); -- cgit