From a89299c40911ee29c6ec4fb66f9c598cd947265b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 8 Nov 2023 13:58:25 +0100 Subject: time: Make sysfs_get_uname() function visible in header MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This function is defined globally in clocksource.c and used conditionally in clockevent.c, which the declaration hidden when clockevent support is disabled. This causes a harmless warning in the definition: kernel/time/clocksource.c:1324:9: warning: no previous prototype for 'sysfs_get_uname' [-Wmissing-prototypes] 1324 | ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt) Move the declaration out of the #ifdef so it is always visible. Signed-off-by: Arnd Bergmann Signed-off-by: Thomas Gleixner Reviewed-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20231108125843.3806765-5-arnd@kernel.org --- kernel/time/tick-internal.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/time') diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index 649f2b48e8f0..481b7ab65e2c 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -56,7 +56,6 @@ extern int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, bool force); extern void clockevents_handle_noop(struct clock_event_device *dev); extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq); -extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt); /* Broadcasting support */ # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST @@ -197,3 +196,5 @@ void hrtimers_resume_local(void); #else #define JIFFIES_SHIFT 8 #endif + +extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt); -- cgit v1.2.3 From cb665db94fc61512c9c94ed1d42af67e7bf6ce01 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:23 +0100 Subject: tick-sched: Fix function names in comments When referencing functions in comments, it might be helpful to use full function names (including the prefix) to be able to find it when grepping. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-2-anna-maria@linutronix.de --- kernel/time/tick-sched.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index be77b021e5d6..ff25fdff6b7c 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -920,11 +920,11 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu) } /* - * nohz_stop_sched_tick() can be called several times before - * nohz_restart_sched_tick() is called. This happens when - * interrupts arrive which do not cause a reschedule. In the - * first call we save the current tick time, so we can restart - * the scheduler tick in nohz_restart_sched_tick(). + * tick_nohz_stop_tick() can be called several times before + * tick_nohz_restart_sched_tick() is called. This happens when + * interrupts arrive which do not cause a reschedule. In the first + * call we save the current tick time, so we can restart the + * scheduler tick in tick_nohz_restart_sched_tick(). */ if (!ts->tick_stopped) { calc_load_nohz_start(); -- cgit v1.2.3 From 318050671affa92fd166d988d08d4041c7b113c4 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:24 +0100 Subject: tick/sched: Cleanup confusing variables tick_nohz_stop_tick() contains the expires (u64 variable) and tick (ktime_t) variable. In the beginning the value of expires is written to tick. Afterwards none of the variables is changed. They are only used for checks. Drop the not required variable tick and use always expires instead. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-3-anna-maria@linutronix.de --- kernel/time/tick-sched.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index ff25fdff6b7c..fce3c6f0e4a6 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -887,7 +887,6 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu) struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev); u64 basemono = ts->timer_expires_base; u64 expires = ts->timer_expires; - ktime_t tick = expires; /* Make sure we won't be trying to stop it twice in a row. */ ts->timer_expires_base = 0; @@ -910,7 +909,7 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu) /* Skip reprogram of event if it's not changed */ if (ts->tick_stopped && (expires == ts->next_tick)) { /* Sanity check: make sure clockevent is actually programmed */ - if (tick == KTIME_MAX || ts->next_tick == hrtimer_get_expires(&ts->sched_timer)) + if (expires == KTIME_MAX || ts->next_tick == hrtimer_get_expires(&ts->sched_timer)) return; WARN_ON_ONCE(1); @@ -935,7 +934,7 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu) trace_tick_stop(1, TICK_DEP_MASK_NONE); } - ts->next_tick = tick; + ts->next_tick = expires; /* * If the expiration time == KTIME_MAX, then we simply stop @@ -950,11 +949,11 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu) } if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { - hrtimer_start(&ts->sched_timer, tick, + hrtimer_start(&ts->sched_timer, expires, HRTIMER_MODE_ABS_PINNED_HARD); } else { - hrtimer_set_expires(&ts->sched_timer, tick); - tick_program_event(tick, 1); + hrtimer_set_expires(&ts->sched_timer, expires); + tick_program_event(expires, 1); } } -- cgit v1.2.3 From cbf04a22026100dceeceec67fcbf1973383eb32f Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:25 +0100 Subject: tick-sched: Warn when next tick seems to be in the past When the next tick is in the past, the delta between basemono and the next tick gets negativ. But the next tick should never be in the past. The negative effect of a wrong next tick might be a stop of the tick and timers might expire late. To prevent expensive debugging when changing underlying code, add a WARN_ON_ONCE into this code path. To prevent complete misbehaviour, also reset next_tick to basemono in this case. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-4-anna-maria@linutronix.de --- kernel/time/tick-sched.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel/time') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index fce3c6f0e4a6..a17d26002831 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -839,6 +839,10 @@ static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu) ts->next_timer = next_tick; } + /* Make sure next_tick is never before basemono! */ + if (WARN_ON_ONCE(basemono > next_tick)) + next_tick = basemono; + /* * If the tick is due in the next period, keep it ticking or * force prod the timer. -- cgit v1.2.3 From dbcdcb62b59db2cf6a24113873b90da15c6f0b19 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:26 +0100 Subject: tracing/timers: Enhance timer_start tracepoint For starting a timer, the timer is enqueued into a bucket of the timer wheel. The bucket expiry is the defacto expiry of the timer but it is not equal the timer expiry because of increasing granularity when bucket is in a higher level of the wheel. To be able to figure out in a trace whether a timer expired in time or not, the bucket expiry time is required as well. Add bucket expiry time to the timer_start tracepoint and thereby simplify the arguments. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-5-anna-maria@linutronix.de --- include/trace/events/timer.h | 20 ++++++++++---------- kernel/time/timer.c | 2 +- 2 files changed, 11 insertions(+), 11 deletions(-) (limited to 'kernel/time') diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index b4bc2828fa09..99ada928d445 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -46,22 +46,21 @@ DEFINE_EVENT(timer_class, timer_init, /** * timer_start - called when the timer is started - * @timer: pointer to struct timer_list - * @expires: the timers expiry time - * @flags: the timers flags + * @timer: pointer to struct timer_list + * @bucket_expiry: the bucket expiry time */ TRACE_EVENT(timer_start, TP_PROTO(struct timer_list *timer, - unsigned long expires, - unsigned int flags), + unsigned long bucket_expiry), - TP_ARGS(timer, expires, flags), + TP_ARGS(timer, bucket_expiry), TP_STRUCT__entry( __field( void *, timer ) __field( void *, function ) __field( unsigned long, expires ) + __field( unsigned long, bucket_expiry ) __field( unsigned long, now ) __field( unsigned int, flags ) ), @@ -69,15 +68,16 @@ TRACE_EVENT(timer_start, TP_fast_assign( __entry->timer = timer; __entry->function = timer->function; - __entry->expires = expires; + __entry->expires = timer->expires; + __entry->bucket_expiry = bucket_expiry; __entry->now = jiffies; - __entry->flags = flags; + __entry->flags = timer->flags; ), - TP_printk("timer=%p function=%ps expires=%lu [timeout=%ld] cpu=%u idx=%u flags=%s", + TP_printk("timer=%p function=%ps expires=%lu [timeout=%ld] bucket_expiry=%lu cpu=%u idx=%u flags=%s", __entry->timer, __entry->function, __entry->expires, (long)__entry->expires - __entry->now, - __entry->flags & TIMER_CPUMASK, + __entry->bucket_expiry, __entry->flags & TIMER_CPUMASK, __entry->flags >> TIMER_ARRAYSHIFT, decode_timer_flags(__entry->flags & TIMER_TRACE_FLAGMASK)) ); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 63a8ce7177dd..a81d793a43d0 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -606,7 +606,7 @@ static void enqueue_timer(struct timer_base *base, struct timer_list *timer, __set_bit(idx, base->pending_map); timer_set_idx(timer, idx); - trace_timer_start(timer, timer->expires, timer->flags); + trace_timer_start(timer, bucket_expiry); /* * Check whether this is the new first expiring timer. The -- cgit v1.2.3 From b573c73101d8786446535b2ab28cbc8907bda9a9 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:27 +0100 Subject: tracing/timers: Add tracepoint for tracking timer base is_idle flag When debugging timer code the timer tracepoints are very important. There is no tracepoint when the is_idle flag of the timer base changes. Instead of always adding manually trace_printk(), add tracepoints which can be easily enabled whenever required. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-6-anna-maria@linutronix.de --- include/trace/events/timer.h | 20 ++++++++++++++++++++ kernel/time/timer.c | 14 +++++++++++--- 2 files changed, 31 insertions(+), 3 deletions(-) (limited to 'kernel/time') diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index 99ada928d445..1ef58a04fc57 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -142,6 +142,26 @@ DEFINE_EVENT(timer_class, timer_cancel, TP_ARGS(timer) ); +TRACE_EVENT(timer_base_idle, + + TP_PROTO(bool is_idle, unsigned int cpu), + + TP_ARGS(is_idle, cpu), + + TP_STRUCT__entry( + __field( bool, is_idle ) + __field( unsigned int, cpu ) + ), + + TP_fast_assign( + __entry->is_idle = is_idle; + __entry->cpu = cpu; + ), + + TP_printk("is_idle=%d cpu=%d", + __entry->is_idle, __entry->cpu) +); + #define decode_clockid(type) \ __print_symbolic(type, \ { CLOCK_REALTIME, "CLOCK_REALTIME" }, \ diff --git a/kernel/time/timer.c b/kernel/time/timer.c index a81d793a43d0..ed8d6063d9ef 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1950,7 +1950,10 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) if (time_before_eq(nextevt, basej)) { expires = basem; - base->is_idle = false; + if (base->is_idle) { + base->is_idle = false; + trace_timer_base_idle(false, base->cpu); + } } else { if (base->timers_pending) expires = basem + (u64)(nextevt - basej) * TICK_NSEC; @@ -1961,8 +1964,10 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) * logic is only maintained for the BASE_STD base, deferrable * timers may still see large granularity skew (by design). */ - if ((expires - basem) > TICK_NSEC) + if ((expires - basem) > TICK_NSEC && !base->is_idle) { base->is_idle = true; + trace_timer_base_idle(true, base->cpu); + } } raw_spin_unlock(&base->lock); @@ -1984,7 +1989,10 @@ void timer_clear_idle(void) * sending the IPI a few instructions smaller for the cost of taking * the lock in the exit from idle path. */ - base->is_idle = false; + if (base->is_idle) { + base->is_idle = false; + trace_timer_base_idle(false, smp_processor_id()); + } } #endif -- cgit v1.2.3 From d124c3393e798b1fb142ee728d5c8976d11e722d Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:28 +0100 Subject: timers: Do not IPI for deferrable timers Deferrable timers do not prevent CPU from going idle and are not taken into account on idle path. Sending an IPI to a remote CPU when a new first deferrable timer was enqueued will wake up the remote CPU but nothing will be done regarding the deferrable timers. Drop IPI completely when a new first deferrable timer was enqueued. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-7-anna-maria@linutronix.de --- kernel/time/timer.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index ed8d6063d9ef..91882059bf3d 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -571,18 +571,15 @@ static int calc_wheel_index(unsigned long expires, unsigned long clk, static void trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer) { - if (!is_timers_nohz_active()) - return; - /* - * TODO: This wants some optimizing similar to the code below, but we - * will do that when we switch from push to pull for deferrable timers. + * Deferrable timers do not prevent the CPU from entering dynticks and + * are not taken into account on the idle/nohz_full path. An IPI when a + * new deferrable timer is enqueued will wake up the remote CPU but + * nothing will be done with the deferrable timer base. Therefore skip + * the remote IPI for deferrable timers completely. */ - if (timer->flags & TIMER_DEFERRABLE) { - if (tick_nohz_full_cpu(base->cpu)) - wake_up_nohz_cpu(base->cpu); + if (!is_timers_nohz_active() || timer->flags & TIMER_DEFERRABLE) return; - } /* * We might have to IPI the remote CPU if the base is idle and the -- cgit v1.2.3 From b5e6f59888c7bde3c05f61b3ce06b78a86713fc0 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:29 +0100 Subject: timers: Move store of next event into __next_timer_interrupt() Both call sites of __next_timer_interrupt() store the return value directly in base->next_expiry. Move the store into __next_timer_interrupt() and to make its purpose more clear, rename the function to next_expiry_recalc(). No functional change. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-8-anna-maria@linutronix.de --- kernel/time/timer.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 91882059bf3d..490ff8e66fc2 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1800,8 +1800,10 @@ static int next_pending_bucket(struct timer_base *base, unsigned offset, /* * Search the first expiring timer in the various clock levels. Caller must * hold base->lock. + * + * Store next expiry time in base->next_expiry. */ -static unsigned long __next_timer_interrupt(struct timer_base *base) +static void next_expiry_recalc(struct timer_base *base) { unsigned long clk, next, adj; unsigned lvl, offset = 0; @@ -1867,10 +1869,9 @@ static unsigned long __next_timer_interrupt(struct timer_base *base) clk += adj; } + base->next_expiry = next; base->next_expiry_recalc = false; base->timers_pending = !(next == base->clk + NEXT_TIMER_MAX_DELTA); - - return next; } #ifdef CONFIG_NO_HZ_COMMON @@ -1930,7 +1931,7 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) raw_spin_lock(&base->lock); if (base->next_expiry_recalc) - base->next_expiry = __next_timer_interrupt(base); + next_expiry_recalc(base); nextevt = base->next_expiry; /* @@ -2021,7 +2022,7 @@ static inline void __run_timers(struct timer_base *base) WARN_ON_ONCE(!levels && !base->next_expiry_recalc && base->timers_pending); base->clk++; - base->next_expiry = __next_timer_interrupt(base); + next_expiry_recalc(base); while (levels--) expire_timers(base, heads + levels); -- cgit v1.2.3 From 8a2c9c7e7848d7f63d38b698209148b5bb4ba7f3 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:30 +0100 Subject: timers: Clarify check in forward_timer_base() The current check whether a forward of the timer base is required can be simplified by using an already existing comparison function which is easier to read. The related comment is outdated and was not updated when the check changed in commit 36cd28a4cdd0 ("timers: Lower base clock forwarding threshold"). Use time_before_eq() for the check and replace the comment by copying the comment from the same check inside get_next_timer_interrupt(). Move the precious information of the outdated comment to the proper place in __run_timers(). No functional change. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-9-anna-maria@linutronix.de --- kernel/time/timer.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 490ff8e66fc2..f75f932b128e 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -944,11 +944,10 @@ static inline void forward_timer_base(struct timer_base *base) unsigned long jnow = READ_ONCE(jiffies); /* - * No need to forward if we are close enough below jiffies. - * Also while executing timers, base->clk is 1 offset ahead - * of jiffies to avoid endless requeuing to current jiffies. + * Check whether we can forward the base. We can only do that when + * @basej is past base->clk otherwise we might rewind base->clk. */ - if ((long)(jnow - base->clk) < 1) + if (time_before_eq(jnow, base->clk)) return; /* @@ -2021,6 +2020,10 @@ static inline void __run_timers(struct timer_base *base) */ WARN_ON_ONCE(!levels && !base->next_expiry_recalc && base->timers_pending); + /* + * While executing timers, base->clk is set 1 offset ahead of + * jiffies to avoid endless requeuing to current jiffies. + */ base->clk++; next_expiry_recalc(base); -- cgit v1.2.3 From 1e490484aa3af42d4eeffabf96d6a02be69d586b Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:31 +0100 Subject: timers: Split out forward timer base functionality Forwarding timer base is done when the next expiry value is calculated and when a new timer is enqueued. When the next expiry value is calculated the jiffies value is already available and does not need to be reread a second time. Splitting out the forward timer base functionality to make it executable via both contextes - those where jiffies are already known and those, where jiffies need to be read. No functional change. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-10-anna-maria@linutronix.de --- kernel/time/timer.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index f75f932b128e..5b02e169ab23 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -939,30 +939,34 @@ get_target_base(struct timer_base *base, unsigned tflags) return get_timer_this_cpu_base(tflags); } -static inline void forward_timer_base(struct timer_base *base) +static inline void __forward_timer_base(struct timer_base *base, + unsigned long basej) { - unsigned long jnow = READ_ONCE(jiffies); - /* * Check whether we can forward the base. We can only do that when * @basej is past base->clk otherwise we might rewind base->clk. */ - if (time_before_eq(jnow, base->clk)) + if (time_before_eq(basej, base->clk)) return; /* * If the next expiry value is > jiffies, then we fast forward to * jiffies otherwise we forward to the next expiry value. */ - if (time_after(base->next_expiry, jnow)) { - base->clk = jnow; + if (time_after(base->next_expiry, basej)) { + base->clk = basej; } else { if (WARN_ON_ONCE(time_before(base->next_expiry, base->clk))) return; base->clk = base->next_expiry; } + } +static inline void forward_timer_base(struct timer_base *base) +{ + __forward_timer_base(base, READ_ONCE(jiffies)); +} /* * We are using hashed locking: Holding per_cpu(timer_bases[x]).lock means -- cgit v1.2.3 From 7a39a5080ef0e3cf233d92165f6a778f08a08244 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:32 +0100 Subject: timers: Use already existing function for forwarding timer base There is an already existing function for forwarding the timer base. Forwarding the timer base is implemented directly in get_next_timer_interrupt() as well. Remove the code duplication and invoke __forward_timer_base() instead. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-11-anna-maria@linutronix.de --- kernel/time/timer.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 5b02e169ab23..1a73d396101b 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1939,15 +1939,9 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) /* * We have a fresh next event. Check whether we can forward the - * base. We can only do that when @basej is past base->clk - * otherwise we might rewind base->clk. + * base. */ - if (time_after(basej, base->clk)) { - if (time_after(nextevt, basej)) - base->clk = basej; - else if (time_after(nextevt, base->clk)) - base->clk = nextevt; - } + __forward_timer_base(base, basej); if (time_before_eq(nextevt, basej)) { expires = basem; -- cgit v1.2.3 From bb8caad5083f8fbba70faf41f1d3bab7cf09da6d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 1 Dec 2023 10:26:33 +0100 Subject: timers: Rework idle logic To improve readability of the code, split base->idle calculation and expires calculation into separate parts. While at it, update the comment about timer base idle marking. Thereby the following subtle change happens if the next event is just one jiffy ahead and the tick was already stopped: Originally base->is_idle remains true in this situation. Now base->is_idle turns to false. This may spare an IPI if a timer is enqueued remotely to an idle CPU that is going to tick on the next jiffy. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-12-anna-maria@linutronix.de --- kernel/time/timer.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 1a73d396101b..cf51655add64 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1924,6 +1924,7 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]); u64 expires = KTIME_MAX; unsigned long nextevt; + bool was_idle; /* * Pretend that there is no timer pending if the cpu is offline. @@ -1943,27 +1944,26 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) */ __forward_timer_base(base, basej); - if (time_before_eq(nextevt, basej)) { - expires = basem; - if (base->is_idle) { - base->is_idle = false; - trace_timer_base_idle(false, base->cpu); - } - } else { - if (base->timers_pending) - expires = basem + (u64)(nextevt - basej) * TICK_NSEC; - /* - * If we expect to sleep more than a tick, mark the base idle. - * Also the tick is stopped so any added timer must forward - * the base clk itself to keep granularity small. This idle - * logic is only maintained for the BASE_STD base, deferrable - * timers may still see large granularity skew (by design). - */ - if ((expires - basem) > TICK_NSEC && !base->is_idle) { - base->is_idle = true; - trace_timer_base_idle(true, base->cpu); - } + if (base->timers_pending) { + /* If we missed a tick already, force 0 delta */ + if (time_before(nextevt, basej)) + nextevt = basej; + expires = basem + (u64)(nextevt - basej) * TICK_NSEC; } + + /* + * Base is idle if the next event is more than a tick away. + * + * If the base is marked idle then any timer add operation must forward + * the base clk itself to keep granularity small. This idle logic is + * only maintained for the BASE_STD base, deferrable timers may still + * see large granularity skew (by design). + */ + was_idle = base->is_idle; + base->is_idle = time_after(nextevt, basej + 1); + if (was_idle != base->is_idle) + trace_timer_base_idle(base->is_idle, base->cpu); + raw_spin_unlock(&base->lock); return cmp_next_hrtimer_event(basem, expires); -- cgit v1.2.3 From da65f29dada7f7cbbf0d6375b88a0316f5f7d6f5 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Fri, 1 Dec 2023 10:26:34 +0100 Subject: timers: Fix nextevt calculation when no timers are pending When no timer is queued into an empty timer base, the next_expiry will not be updated. It was originally calculated as base->clk + NEXT_TIMER_MAX_DELTA When the timer base stays empty long enough (> NEXT_TIMER_MAX_DELTA), the next_expiry value of the empty base suggests that there is a timer pending soon. This might be more a kind of a theoretical problem, but the fix doesn't hurt. Use only base->next_expiry value as nextevt when timers are pending. Otherwise nextevt will be jiffies + NEXT_TIMER_MAX_DELTA. As all information is in place, update base->next_expiry value of the empty timer base as well. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20231201092654.34614-13-anna-maria@linutronix.de --- kernel/time/timer.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timer.c b/kernel/time/timer.c index cf51655add64..352b161113cd 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1922,8 +1922,8 @@ static u64 cmp_next_hrtimer_event(u64 basem, u64 expires) u64 get_next_timer_interrupt(unsigned long basej, u64 basem) { struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]); + unsigned long nextevt = basej + NEXT_TIMER_MAX_DELTA; u64 expires = KTIME_MAX; - unsigned long nextevt; bool was_idle; /* @@ -1936,7 +1936,6 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) raw_spin_lock(&base->lock); if (base->next_expiry_recalc) next_expiry_recalc(base); - nextevt = base->next_expiry; /* * We have a fresh next event. Check whether we can forward the @@ -1945,10 +1944,20 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem) __forward_timer_base(base, basej); if (base->timers_pending) { + nextevt = base->next_expiry; + /* If we missed a tick already, force 0 delta */ if (time_before(nextevt, basej)) nextevt = basej; expires = basem + (u64)(nextevt - basej) * TICK_NSEC; + } else { + /* + * Move next_expiry for the empty base into the future to + * prevent a unnecessary raise of the timer softirq when the + * next_expiry value will be reached even if there is no timer + * pending. + */ + base->next_expiry = nextevt; } /* -- cgit v1.2.3 From a4aebe936554dac6a91e5d091179c934f8325708 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 19 Dec 2023 15:26:59 -0800 Subject: posix-timers: Get rid of [COMPAT_]SYS_NI() uses Only the posix timer system calls use this (when the posix timer support is disabled, which does not actually happen in any normal case), because they had debug code to print out a warning about missing system calls. Get rid of that special case, and just use the standard COND_SYSCALL interface that creates weak system call stubs that return -ENOSYS for when the system call does not exist. This fixes a kCFI issue with the SYS_NI() hackery: CFI failure at int80_emulation+0x67/0xb0 (target: sys_ni_posix_timers+0x0/0x70; expected type: 0xb02b34d9) WARNING: CPU: 0 PID: 48 at int80_emulation+0x67/0xb0 Reported-by: kernel test robot Reviewed-by: Sami Tolvanen Tested-by: Sami Tolvanen Cc: Thomas Gleixner Cc: Dave Hansen Cc: Borislav Petkov Signed-off-by: Linus Torvalds --- arch/arm64/include/asm/syscall_wrapper.h | 4 --- arch/riscv/include/asm/syscall_wrapper.h | 5 ---- arch/s390/include/asm/syscall_wrapper.h | 13 +-------- arch/x86/include/asm/syscall_wrapper.h | 34 +++--------------------- kernel/sys_ni.c | 14 ++++++++++ kernel/time/posix-stubs.c | 45 -------------------------------- 6 files changed, 19 insertions(+), 96 deletions(-) (limited to 'kernel/time') diff --git a/arch/arm64/include/asm/syscall_wrapper.h b/arch/arm64/include/asm/syscall_wrapper.h index d977713ec0ba..abb57bc54305 100644 --- a/arch/arm64/include/asm/syscall_wrapper.h +++ b/arch/arm64/include/asm/syscall_wrapper.h @@ -44,9 +44,6 @@ return sys_ni_syscall(); \ } -#define COMPAT_SYS_NI(name) \ - SYSCALL_ALIAS(__arm64_compat_sys_##name, sys_ni_posix_timers); - #endif /* CONFIG_COMPAT */ #define __SYSCALL_DEFINEx(x, name, ...) \ @@ -81,6 +78,5 @@ } asmlinkage long __arm64_sys_ni_syscall(const struct pt_regs *__unused); -#define SYS_NI(name) SYSCALL_ALIAS(__arm64_sys_##name, sys_ni_posix_timers); #endif /* __ASM_SYSCALL_WRAPPER_H */ diff --git a/arch/riscv/include/asm/syscall_wrapper.h b/arch/riscv/include/asm/syscall_wrapper.h index 1d7942c8a6cb..eeec04b7dae6 100644 --- a/arch/riscv/include/asm/syscall_wrapper.h +++ b/arch/riscv/include/asm/syscall_wrapper.h @@ -46,9 +46,6 @@ asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *); return sys_ni_syscall(); \ } -#define COMPAT_SYS_NI(name) \ - SYSCALL_ALIAS(__riscv_compat_sys_##name, sys_ni_posix_timers); - #endif /* CONFIG_COMPAT */ #define __SYSCALL_DEFINEx(x, name, ...) \ @@ -82,6 +79,4 @@ asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *); return sys_ni_syscall(); \ } -#define SYS_NI(name) SYSCALL_ALIAS(__riscv_sys_##name, sys_ni_posix_timers); - #endif /* __ASM_SYSCALL_WRAPPER_H */ diff --git a/arch/s390/include/asm/syscall_wrapper.h b/arch/s390/include/asm/syscall_wrapper.h index 9286430fe729..35c1d1b860d8 100644 --- a/arch/s390/include/asm/syscall_wrapper.h +++ b/arch/s390/include/asm/syscall_wrapper.h @@ -63,10 +63,6 @@ cond_syscall(__s390x_sys_##name); \ cond_syscall(__s390_sys_##name) -#define SYS_NI(name) \ - SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers); \ - SYSCALL_ALIAS(__s390_sys_##name, sys_ni_posix_timers) - #define COMPAT_SYSCALL_DEFINEx(x, name, ...) \ long __s390_compat_sys##name(struct pt_regs *regs); \ ALLOW_ERROR_INJECTION(__s390_compat_sys##name, ERRNO); \ @@ -85,15 +81,11 @@ /* * As some compat syscalls may not be implemented, we need to expand - * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in - * kernel/time/posix-stubs.c to cover this case as well. + * COND_SYSCALL_COMPAT in kernel/sys_ni.c to cover this case as well. */ #define COND_SYSCALL_COMPAT(name) \ cond_syscall(__s390_compat_sys_##name) -#define COMPAT_SYS_NI(name) \ - SYSCALL_ALIAS(__s390_compat_sys_##name, sys_ni_posix_timers) - #define __S390_SYS_STUBx(x, name, ...) \ long __s390_sys##name(struct pt_regs *regs); \ ALLOW_ERROR_INJECTION(__s390_sys##name, ERRNO); \ @@ -124,9 +116,6 @@ #define COND_SYSCALL(name) \ cond_syscall(__s390x_sys_##name) -#define SYS_NI(name) \ - SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers) - #define __S390_SYS_STUBx(x, fullname, name, ...) #endif /* CONFIG_COMPAT */ diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h index fd2669b1cb2d..21f9407be5d3 100644 --- a/arch/x86/include/asm/syscall_wrapper.h +++ b/arch/x86/include/asm/syscall_wrapper.h @@ -86,9 +86,6 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); return sys_ni_syscall(); \ } -#define __SYS_NI(abi, name) \ - SYSCALL_ALIAS(__##abi##_##name, sys_ni_posix_timers); - #ifdef CONFIG_X86_64 #define __X64_SYS_STUB0(name) \ __SYS_STUB0(x64, sys_##name) @@ -100,13 +97,10 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); #define __X64_COND_SYSCALL(name) \ __COND_SYSCALL(x64, sys_##name) -#define __X64_SYS_NI(name) \ - __SYS_NI(x64, sys_##name) #else /* CONFIG_X86_64 */ #define __X64_SYS_STUB0(name) #define __X64_SYS_STUBx(x, name, ...) #define __X64_COND_SYSCALL(name) -#define __X64_SYS_NI(name) #endif /* CONFIG_X86_64 */ #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) @@ -120,13 +114,10 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); #define __IA32_COND_SYSCALL(name) \ __COND_SYSCALL(ia32, sys_##name) -#define __IA32_SYS_NI(name) \ - __SYS_NI(ia32, sys_##name) #else /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */ #define __IA32_SYS_STUB0(name) #define __IA32_SYS_STUBx(x, name, ...) #define __IA32_COND_SYSCALL(name) -#define __IA32_SYS_NI(name) #endif /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */ #ifdef CONFIG_IA32_EMULATION @@ -135,8 +126,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); * additional wrappers (aptly named __ia32_sys_xyzzy) which decode the * ia32 regs in the proper order for shared or "common" syscalls. As some * syscalls may not be implemented, we need to expand COND_SYSCALL in - * kernel/sys_ni.c and SYS_NI in kernel/time/posix-stubs.c to cover this - * case as well. + * kernel/sys_ni.c to cover this case as well. */ #define __IA32_COMPAT_SYS_STUB0(name) \ __SYS_STUB0(ia32, compat_sys_##name) @@ -148,14 +138,10 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); #define __IA32_COMPAT_COND_SYSCALL(name) \ __COND_SYSCALL(ia32, compat_sys_##name) -#define __IA32_COMPAT_SYS_NI(name) \ - __SYS_NI(ia32, compat_sys_##name) - #else /* CONFIG_IA32_EMULATION */ #define __IA32_COMPAT_SYS_STUB0(name) #define __IA32_COMPAT_SYS_STUBx(x, name, ...) #define __IA32_COMPAT_COND_SYSCALL(name) -#define __IA32_COMPAT_SYS_NI(name) #endif /* CONFIG_IA32_EMULATION */ @@ -175,13 +161,10 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); #define __X32_COMPAT_COND_SYSCALL(name) \ __COND_SYSCALL(x64, compat_sys_##name) -#define __X32_COMPAT_SYS_NI(name) \ - __SYS_NI(x64, compat_sys_##name) #else /* CONFIG_X86_X32_ABI */ #define __X32_COMPAT_SYS_STUB0(name) #define __X32_COMPAT_SYS_STUBx(x, name, ...) #define __X32_COMPAT_COND_SYSCALL(name) -#define __X32_COMPAT_SYS_NI(name) #endif /* CONFIG_X86_X32_ABI */ @@ -212,17 +195,12 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); /* * As some compat syscalls may not be implemented, we need to expand - * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in - * kernel/time/posix-stubs.c to cover this case as well. + * COND_SYSCALL_COMPAT in kernel/sys_ni.c to cover this case as well. */ #define COND_SYSCALL_COMPAT(name) \ __IA32_COMPAT_COND_SYSCALL(name) \ __X32_COMPAT_COND_SYSCALL(name) -#define COMPAT_SYS_NI(name) \ - __IA32_COMPAT_SYS_NI(name) \ - __X32_COMPAT_SYS_NI(name) - #endif /* CONFIG_COMPAT */ #define __SYSCALL_DEFINEx(x, name, ...) \ @@ -243,8 +221,8 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not * hurt, we only need to re-define it here to keep the naming congruent to - * SYSCALL_DEFINEx() -- which is essential for the COND_SYSCALL() and SYS_NI() - * macros to work correctly. + * SYSCALL_DEFINEx() -- which is essential for the COND_SYSCALL() macro + * to work correctly. */ #define SYSCALL_DEFINE0(sname) \ SYSCALL_METADATA(_##sname, 0); \ @@ -257,10 +235,6 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); __X64_COND_SYSCALL(name) \ __IA32_COND_SYSCALL(name) -#define SYS_NI(name) \ - __X64_SYS_NI(name) \ - __IA32_SYS_NI(name) - /* * For VSYSCALLS, we need to declare these three syscalls with the new diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index e1a6e3c675c0..9a846439b36a 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -201,6 +201,20 @@ COND_SYSCALL(recvmmsg_time32); COND_SYSCALL_COMPAT(recvmmsg_time32); COND_SYSCALL_COMPAT(recvmmsg_time64); +/* Posix timer syscalls may be configured out */ +COND_SYSCALL(timer_create); +COND_SYSCALL(timer_gettime); +COND_SYSCALL(timer_getoverrun); +COND_SYSCALL(timer_settime); +COND_SYSCALL(timer_delete); +COND_SYSCALL(clock_adjtime); +COND_SYSCALL(getitimer); +COND_SYSCALL(setitimer); +COND_SYSCALL(alarm); +COND_SYSCALL_COMPAT(timer_create); +COND_SYSCALL_COMPAT(getitimer); +COND_SYSCALL_COMPAT(setitimer); + /* * Architecture specific syscalls: see further below */ diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c index 828aeecbd1e8..9b6fcb8d85e7 100644 --- a/kernel/time/posix-stubs.c +++ b/kernel/time/posix-stubs.c @@ -17,40 +17,6 @@ #include #include -#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER -/* Architectures may override SYS_NI and COMPAT_SYS_NI */ -#include -#endif - -asmlinkage long sys_ni_posix_timers(void) -{ - pr_err_once("process %d (%s) attempted a POSIX timer syscall " - "while CONFIG_POSIX_TIMERS is not set\n", - current->pid, current->comm); - return -ENOSYS; -} - -#ifndef SYS_NI -#define SYS_NI(name) SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers) -#endif - -#ifndef COMPAT_SYS_NI -#define COMPAT_SYS_NI(name) SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers) -#endif - -SYS_NI(timer_create); -SYS_NI(timer_gettime); -SYS_NI(timer_getoverrun); -SYS_NI(timer_settime); -SYS_NI(timer_delete); -SYS_NI(clock_adjtime); -SYS_NI(getitimer); -SYS_NI(setitimer); -SYS_NI(clock_adjtime32); -#ifdef __ARCH_WANT_SYS_ALARM -SYS_NI(alarm); -#endif - /* * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC * as it is easy to remain compatible with little code. CLOCK_BOOTTIME @@ -158,18 +124,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags, which_clock); } -#ifdef CONFIG_COMPAT -COMPAT_SYS_NI(timer_create); -#endif - -#if defined(CONFIG_COMPAT) || defined(CONFIG_ALPHA) -COMPAT_SYS_NI(getitimer); -COMPAT_SYS_NI(setitimer); -#endif - #ifdef CONFIG_COMPAT_32BIT_TIME -SYS_NI(timer_settime32); -SYS_NI(timer_gettime32); SYSCALL_DEFINE2(clock_settime32, const clockid_t, which_clock, struct old_timespec32 __user *, tp) -- cgit v1.2.3 From 71fee48fb772ac4f6cfa63dbebc5629de8b4cc09 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 15 Jan 2024 17:35:55 +0100 Subject: tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug When offlining and onlining CPUs the overall reported idle and iowait times as reported by /proc/stat jump backward and forward: cpu 132 0 176 225249 47 6 6 21 0 0 cpu0 80 0 115 112575 33 3 4 18 0 0 cpu1 52 0 60 112673 13 3 1 2 0 0 cpu 133 0 177 226681 47 6 6 21 0 0 cpu0 80 0 116 113387 33 3 4 18 0 0 cpu 133 0 178 114431 33 6 6 21 0 0 <---- jump backward cpu0 80 0 116 114247 33 3 4 18 0 0 cpu1 52 0 61 183 0 3 1 2 0 0 <---- idle + iowait start with 0 cpu 133 0 178 228956 47 6 6 21 0 0 <---- jump forward cpu0 81 0 117 114929 33 3 4 18 0 0 Reason for this is that get_idle_time() in fs/proc/stat.c has different sources for both values depending on if a CPU is online or offline: - if a CPU is online the values may be taken from its per cpu tick_cpu_sched structure - if a CPU is offline the values are taken from its per cpu cpustat structure The problem is that the per cpu tick_cpu_sched structure is set to zero on CPU offline. See tick_cancel_sched_timer() in kernel/time/tick-sched.c. Therefore when a CPU is brought offline and online afterwards both its idle and iowait sleeptime will be zero, causing a jump backward in total system idle and iowait sleeptime. In a similar way if a CPU is then brought offline again the total idle and iowait sleeptimes will jump forward. It looks like this behavior was introduced with commit 4b0c0f294f60 ("tick: Cleanup NOHZ per cpu data on cpu down"). This was only noticed now on s390, since we switched to generic idle time reporting with commit be76ea614460 ("s390/idle: remove arch_cpu_idle_time() and corresponding code"). Fix this by preserving the values of idle_sleeptime and iowait_sleeptime members of the per-cpu tick_sched structure on CPU hotplug. Fixes: 4b0c0f294f60 ("tick: Cleanup NOHZ per cpu data on cpu down") Reported-by: Gerald Schaefer Signed-off-by: Heiko Carstens Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20240115163555.1004144-1-hca@linux.ibm.com --- kernel/time/tick-sched.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/time') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index a17d26002831..d2501673028d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -1576,13 +1576,18 @@ void tick_setup_sched_timer(void) void tick_cancel_sched_timer(int cpu) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + ktime_t idle_sleeptime, iowait_sleeptime; # ifdef CONFIG_HIGH_RES_TIMERS if (ts->sched_timer.base) hrtimer_cancel(&ts->sched_timer); # endif + idle_sleeptime = ts->idle_sleeptime; + iowait_sleeptime = ts->iowait_sleeptime; memset(ts, 0, sizeof(*ts)); + ts->idle_sleeptime = idle_sleeptime; + ts->iowait_sleeptime = iowait_sleeptime; } #endif -- cgit v1.2.3