diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0100-hrtimer-by-timers-by-default-into-the-softirq-contex.patch | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/debian/patches-rt/0100-hrtimer-by-timers-by-default-into-the-softirq-contex.patch b/debian/patches-rt/0100-hrtimer-by-timers-by-default-into-the-softirq-contex.patch new file mode 100644 index 000000000..1b924bac1 --- /dev/null +++ b/debian/patches-rt/0100-hrtimer-by-timers-by-default-into-the-softirq-contex.patch @@ -0,0 +1,237 @@ +From 8a7e45b02f567fa32754c24195d5c0d095069685 Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Fri, 3 Jul 2009 08:44:31 -0500 +Subject: [PATCH 100/347] hrtimer: by timers by default into the softirq + context +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +We can't have hrtimers callbacks running in hardirq context on RT. Therefore +the timers are deferred to the softirq context by default. +There are few timers which expect to be run in hardirq context even on RT. +Those are: +- very short running where low latency is critical (kvm lapic) +- timers which take raw locks and need run in hard-irq context (perf, sched) +- wake up related timer (kernel side of clock_nanosleep() and so on) + +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + arch/x86/kvm/lapic.c | 2 +- + include/linux/hrtimer.h | 6 ++++++ + kernel/events/core.c | 4 ++-- + kernel/sched/core.c | 2 +- + kernel/sched/deadline.c | 2 +- + kernel/sched/fair.c | 4 ++-- + kernel/sched/rt.c | 4 ++-- + kernel/time/hrtimer.c | 21 +++++++++++++++++++-- + kernel/time/tick-broadcast-hrtimer.c | 2 +- + kernel/time/tick-sched.c | 2 +- + kernel/watchdog.c | 2 +- + 11 files changed, 37 insertions(+), 14 deletions(-) + +diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c +index 89d07312e58c..037dbe04fda2 100644 +--- a/arch/x86/kvm/lapic.c ++++ b/arch/x86/kvm/lapic.c +@@ -2258,7 +2258,7 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu) + apic->vcpu = vcpu; + + hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC, +- HRTIMER_MODE_ABS_PINNED); ++ HRTIMER_MODE_ABS_PINNED_HARD); + apic->lapic_timer.timer.function = apic_timer_fn; + + /* +diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h +index 8714f1a37d84..082147c07831 100644 +--- a/include/linux/hrtimer.h ++++ b/include/linux/hrtimer.h +@@ -42,6 +42,7 @@ enum hrtimer_mode { + HRTIMER_MODE_REL = 0x01, + HRTIMER_MODE_PINNED = 0x02, + HRTIMER_MODE_SOFT = 0x04, ++ HRTIMER_MODE_HARD = 0x08, + + HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED, + HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED, +@@ -52,6 +53,11 @@ enum hrtimer_mode { + HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT, + HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT, + ++ HRTIMER_MODE_ABS_HARD = HRTIMER_MODE_ABS | HRTIMER_MODE_HARD, ++ HRTIMER_MODE_REL_HARD = HRTIMER_MODE_REL | HRTIMER_MODE_HARD, ++ ++ HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_HARD, ++ HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD, + }; + + /* +diff --git a/kernel/events/core.c b/kernel/events/core.c +index 88dd1398ae88..7f2441f671d3 100644 +--- a/kernel/events/core.c ++++ b/kernel/events/core.c +@@ -1108,7 +1108,7 @@ static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu) + cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval); + + raw_spin_lock_init(&cpuctx->hrtimer_lock); +- hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); ++ hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD); + timer->function = perf_mux_hrtimer_handler; + } + +@@ -9311,7 +9311,7 @@ static void perf_swevent_init_hrtimer(struct perf_event *event) + if (!is_sampling_event(event)) + return; + +- hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); ++ hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); + hwc->hrtimer.function = perf_swevent_hrtimer; + + /* +diff --git a/kernel/sched/core.c b/kernel/sched/core.c +index 3c5999476609..0f949b7738fd 100644 +--- a/kernel/sched/core.c ++++ b/kernel/sched/core.c +@@ -315,7 +315,7 @@ static void hrtick_rq_init(struct rq *rq) + rq->hrtick_csd.info = rq; + #endif + +- hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); ++ hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); + rq->hrtick_timer.function = hrtick; + } + #else /* CONFIG_SCHED_HRTICK */ +diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c +index 95ebbb2074c7..1a285367081c 100644 +--- a/kernel/sched/deadline.c ++++ b/kernel/sched/deadline.c +@@ -1086,7 +1086,7 @@ void init_dl_task_timer(struct sched_dl_entity *dl_se) + { + struct hrtimer *timer = &dl_se->dl_timer; + +- hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); ++ hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); + timer->function = dl_task_timer; + } + +diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c +index 16940416d526..d804b5443bb9 100644 +--- a/kernel/sched/fair.c ++++ b/kernel/sched/fair.c +@@ -4951,9 +4951,9 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) + cfs_b->period = ns_to_ktime(default_cfs_period()); + + INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq); +- hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); ++ hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD); + cfs_b->period_timer.function = sched_cfs_period_timer; +- hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); ++ hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); + cfs_b->slack_timer.function = sched_cfs_slack_timer; + cfs_b->distribute_running = 0; + } +diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c +index 52b55144d8ad..a2f2c6c91e05 100644 +--- a/kernel/sched/rt.c ++++ b/kernel/sched/rt.c +@@ -45,8 +45,8 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) + + raw_spin_lock_init(&rt_b->rt_runtime_lock); + +- hrtimer_init(&rt_b->rt_period_timer, +- CLOCK_MONOTONIC, HRTIMER_MODE_REL); ++ hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC, ++ HRTIMER_MODE_REL_HARD); + rt_b->rt_period_timer.function = sched_rt_period_timer; + } + +diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c +index 8bbde17325c7..e947f3b344ac 100644 +--- a/kernel/time/hrtimer.c ++++ b/kernel/time/hrtimer.c +@@ -1202,7 +1202,9 @@ void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, + * Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft + * match. + */ ++#ifndef CONFIG_PREEMPT_RT_BASE + WARN_ON_ONCE(!(mode & HRTIMER_MODE_SOFT) ^ !timer->is_soft); ++#endif + + base = lock_hrtimer_base(timer, &flags); + +@@ -1362,10 +1364,17 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id) + static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, + enum hrtimer_mode mode) + { +- bool softtimer = !!(mode & HRTIMER_MODE_SOFT); +- int base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0; ++ bool softtimer; ++ int base; + struct hrtimer_cpu_base *cpu_base; + ++ softtimer = !!(mode & HRTIMER_MODE_SOFT); ++#ifdef CONFIG_PREEMPT_RT_FULL ++ if (!softtimer && !(mode & HRTIMER_MODE_HARD)) ++ softtimer = true; ++#endif ++ base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0; ++ + memset(timer, 0, sizeof(struct hrtimer)); + + cpu_base = raw_cpu_ptr(&hrtimer_bases); +@@ -1748,6 +1757,14 @@ static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl, + enum hrtimer_mode mode, + struct task_struct *task) + { ++#ifdef CONFIG_PREEMPT_RT_FULL ++ if (!(mode & (HRTIMER_MODE_SOFT | HRTIMER_MODE_HARD))) { ++ if (task_is_realtime(current) || system_state != SYSTEM_RUNNING) ++ mode |= HRTIMER_MODE_HARD; ++ else ++ mode |= HRTIMER_MODE_SOFT; ++ } ++#endif + __hrtimer_init(&sl->timer, clock_id, mode); + sl->timer.function = hrtimer_wakeup; + sl->task = task; +diff --git a/kernel/time/tick-broadcast-hrtimer.c b/kernel/time/tick-broadcast-hrtimer.c +index a836efd34589..c50e8f3262de 100644 +--- a/kernel/time/tick-broadcast-hrtimer.c ++++ b/kernel/time/tick-broadcast-hrtimer.c +@@ -107,7 +107,7 @@ static enum hrtimer_restart bc_handler(struct hrtimer *t) + + void tick_setup_hrtimer_broadcast(void) + { +- hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); ++ hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); + bctimer.function = bc_handler; + clockevents_register_device(&ce_broadcast_hrtimer); + } +diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c +index e774a49176cc..012bc81879bf 100644 +--- a/kernel/time/tick-sched.c ++++ b/kernel/time/tick-sched.c +@@ -1314,7 +1314,7 @@ void tick_setup_sched_timer(void) + /* + * Emulate tick processing via per-CPU hrtimers: + */ +- hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); ++ hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); + ts->sched_timer.function = tick_sched_timer; + + /* Get the next period (per-CPU) */ +diff --git a/kernel/watchdog.c b/kernel/watchdog.c +index 6d60701dc636..328620fe85f6 100644 +--- a/kernel/watchdog.c ++++ b/kernel/watchdog.c +@@ -485,7 +485,7 @@ static void watchdog_enable(unsigned int cpu) + * Start the timer first to prevent the NMI watchdog triggering + * before the timer has a chance to fire. + */ +- hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); ++ hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); + hrtimer->function = watchdog_timer_fn; + hrtimer_start(hrtimer, ns_to_ktime(sample_period), + HRTIMER_MODE_REL_PINNED); +-- +2.36.1 + |