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-rw-r--r--kernel/Kconfig.preempt15
-rw-r--r--kernel/exit.c2
-rw-r--r--kernel/module.c15
-rw-r--r--kernel/sched.c39
-rw-r--r--kernel/sched_fair.c14
-rw-r--r--kernel/sched_rt.c6
-rw-r--r--kernel/time/ntp.c23
-rw-r--r--kernel/time/tick-sched.c2
-rw-r--r--kernel/time/timekeeping.c6
9 files changed, 95 insertions, 27 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 0669b70fa6a..9fdba03dc1f 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -52,8 +52,23 @@ config PREEMPT
endchoice
+config PREEMPT_RCU
+ bool "Preemptible RCU"
+ depends on PREEMPT
+ default n
+ help
+ This option reduces the latency of the kernel by making certain
+ RCU sections preemptible. Normally RCU code is non-preemptible, if
+ this option is selected then read-only RCU sections become
+ preemptible. This helps latency, but may expose bugs due to
+ now-naive assumptions about each RCU read-side critical section
+ remaining on a given CPU through its execution.
+
+ Say N if you are unsure.
+
config RCU_TRACE
bool "Enable tracing for RCU - currently stats in debugfs"
+ depends on PREEMPT_RCU
select DEBUG_FS
default y
help
diff --git a/kernel/exit.c b/kernel/exit.c
index cd20bf07e9e..53872bf993f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1378,7 +1378,7 @@ unlock_sig:
if (!retval && infop)
retval = put_user(0, &infop->si_errno);
if (!retval && infop)
- retval = put_user(why, &infop->si_code);
+ retval = put_user((short)why, &infop->si_code);
if (!retval && infop)
retval = put_user(exit_code, &infop->si_status);
if (!retval && infop)
diff --git a/kernel/module.c b/kernel/module.c
index be4807fb90e..5d437bffd8d 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2178,10 +2178,20 @@ sys_init_module(void __user *umod,
wake_up(&module_wq);
return ret;
}
+ if (ret > 0) {
+ printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, "
+ "it should follow 0/-E convention\n"
+ KERN_WARNING "%s: loading module anyway...\n",
+ __func__, mod->name, ret,
+ __func__);
+ dump_stack();
+ }
- /* Now it's a first class citizen! */
- mutex_lock(&module_mutex);
+ /* Now it's a first class citizen! Wake up anyone waiting for it. */
mod->state = MODULE_STATE_LIVE;
+ wake_up(&module_wq);
+
+ mutex_lock(&module_mutex);
/* Drop initial reference. */
module_put(mod);
unwind_remove_table(mod->unwind_info, 1);
@@ -2190,7 +2200,6 @@ sys_init_module(void __user *umod,
mod->init_size = 0;
mod->init_text_size = 0;
mutex_unlock(&module_mutex);
- wake_up(&module_wq);
return 0;
}
diff --git a/kernel/sched.c b/kernel/sched.c
index dcd553cc4ee..1cb53fb1fe3 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4422,7 +4422,7 @@ int task_nice(const struct task_struct *p)
{
return TASK_NICE(p);
}
-EXPORT_SYMBOL_GPL(task_nice);
+EXPORT_SYMBOL(task_nice);
/**
* idle_cpu - is a given cpu idle currently?
@@ -5100,7 +5100,7 @@ long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval)
time_slice = 0;
if (p->policy == SCHED_RR) {
time_slice = DEF_TIMESLICE;
- } else {
+ } else if (p->policy != SCHED_FIFO) {
struct sched_entity *se = &p->se;
unsigned long flags;
struct rq *rq;
@@ -5881,7 +5881,8 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
spin_unlock_irq(&rq->lock);
break;
- case CPU_DOWN_PREPARE:
+ case CPU_DYING:
+ case CPU_DYING_FROZEN:
/* Update our root-domain */
rq = cpu_rq(cpu);
spin_lock_irqsave(&rq->lock, flags);
@@ -7625,6 +7626,11 @@ void sched_move_task(struct task_struct *tsk)
set_task_rq(tsk, task_cpu(tsk));
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ if (tsk->sched_class->moved_group)
+ tsk->sched_class->moved_group(tsk);
+#endif
+
if (on_rq) {
if (unlikely(running))
tsk->sched_class->set_curr_task(rq);
@@ -7721,9 +7727,7 @@ static unsigned long to_ratio(u64 period, u64 runtime)
if (runtime == RUNTIME_INF)
return 1ULL << 16;
- runtime *= (1ULL << 16);
- div64_64(runtime, period);
- return runtime;
+ return div64_64(runtime << 16, period);
}
static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
@@ -7747,25 +7751,40 @@ static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
return total + to_ratio(period, runtime) < global_ratio;
}
+/* Must be called with tasklist_lock held */
+static inline int tg_has_rt_tasks(struct task_group *tg)
+{
+ struct task_struct *g, *p;
+ do_each_thread(g, p) {
+ if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg)
+ return 1;
+ } while_each_thread(g, p);
+ return 0;
+}
+
int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
{
u64 rt_runtime, rt_period;
int err = 0;
- rt_period = sysctl_sched_rt_period * NSEC_PER_USEC;
+ rt_period = (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
if (rt_runtime_us == -1)
- rt_runtime = rt_period;
+ rt_runtime = RUNTIME_INF;
mutex_lock(&rt_constraints_mutex);
+ read_lock(&tasklist_lock);
+ if (rt_runtime_us == 0 && tg_has_rt_tasks(tg)) {
+ err = -EBUSY;
+ goto unlock;
+ }
if (!__rt_schedulable(tg, rt_period, rt_runtime)) {
err = -EINVAL;
goto unlock;
}
- if (rt_runtime_us == -1)
- rt_runtime = RUNTIME_INF;
tg->rt_runtime = rt_runtime;
unlock:
+ read_unlock(&tasklist_lock);
mutex_unlock(&rt_constraints_mutex);
return err;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 3df4d46994c..e2a53051561 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1353,6 +1353,16 @@ static void set_curr_task_fair(struct rq *rq)
set_next_entity(cfs_rq_of(se), se);
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static void moved_group_fair(struct task_struct *p)
+{
+ struct cfs_rq *cfs_rq = task_cfs_rq(p);
+
+ update_curr(cfs_rq);
+ place_entity(cfs_rq, &p->se, 1);
+}
+#endif
+
/*
* All the scheduling class methods:
*/
@@ -1381,6 +1391,10 @@ static const struct sched_class fair_sched_class = {
.prio_changed = prio_changed_fair,
.switched_to = switched_to_fair,
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ .moved_group = moved_group_fair,
+#endif
};
#ifdef CONFIG_SCHED_DEBUG
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 76e82851754..0a6d2e51642 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1107,9 +1107,11 @@ static void prio_changed_rt(struct rq *rq, struct task_struct *p,
pull_rt_task(rq);
/*
* If there's a higher priority task waiting to run
- * then reschedule.
+ * then reschedule. Note, the above pull_rt_task
+ * can release the rq lock and p could migrate.
+ * Only reschedule if p is still on the same runqueue.
*/
- if (p->prio > rq->rt.highest_prio)
+ if (p->prio > rq->rt.highest_prio && rq->curr == p)
resched_task(p);
#else
/* For UP simply resched on drop of prio */
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index c88b5910e7a..5fd9b946977 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -42,12 +42,13 @@ long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
long time_freq; /* frequency offset (scaled ppm)*/
static long time_reftime; /* time at last adjustment (s) */
long time_adjust;
+static long ntp_tick_adj;
static void ntp_update_frequency(void)
{
u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
<< TICK_LENGTH_SHIFT;
- second_length += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
+ second_length += (s64)ntp_tick_adj << TICK_LENGTH_SHIFT;
second_length += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC);
tick_length_base = second_length;
@@ -342,14 +343,16 @@ int do_adjtimex(struct timex *txc)
freq_adj = shift_right(freq_adj, time_constant * 2 +
(SHIFT_PLL + 2) * 2 - SHIFT_NSEC);
if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
+ u64 utemp64;
temp64 = time_offset << (SHIFT_NSEC - SHIFT_FLL);
if (time_offset < 0) {
- temp64 = -temp64;
- do_div(temp64, mtemp);
- freq_adj -= temp64;
+ utemp64 = -temp64;
+ do_div(utemp64, mtemp);
+ freq_adj -= utemp64;
} else {
- do_div(temp64, mtemp);
- freq_adj += temp64;
+ utemp64 = temp64;
+ do_div(utemp64, mtemp);
+ freq_adj += utemp64;
}
}
freq_adj += time_freq;
@@ -400,3 +403,11 @@ leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
notify_cmos_timer();
return(result);
}
+
+static int __init ntp_tick_adj_setup(char *str)
+{
+ ntp_tick_adj = simple_strtol(str, NULL, 0);
+ return 1;
+}
+
+__setup("ntp_tick_adj=", ntp_tick_adj_setup);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 2968298f8f3..686da821d37 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -640,7 +640,7 @@ void tick_cancel_sched_timer(int cpu)
if (ts->sched_timer.base)
hrtimer_cancel(&ts->sched_timer);
- ts->tick_stopped = 0;
+
ts->nohz_mode = NOHZ_MODE_INACTIVE;
}
#endif /* HIGH_RES_TIMERS */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 1af9fb050fe..671af612b76 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -187,8 +187,7 @@ static void change_clocksource(void)
clock->error = 0;
clock->xtime_nsec = 0;
- clocksource_calculate_interval(clock,
- (unsigned long)(current_tick_length()>>TICK_LENGTH_SHIFT));
+ clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
tick_clock_notify();
@@ -245,8 +244,7 @@ void __init timekeeping_init(void)
ntp_clear();
clock = clocksource_get_next();
- clocksource_calculate_interval(clock,
- (unsigned long)(current_tick_length()>>TICK_LENGTH_SHIFT));
+ clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
clock->cycle_last = clocksource_read(clock);
xtime.tv_sec = sec;
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-16 15:38:42 +0000