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Merge branch 'timers/urgent' into timers/core

Browse Source 
Reason: Update to upstream changes to avoid further conflicts.
Fixup a trivial merge conflict in kernel/time/tick-sched.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner
2012-07-15 10:24:53 +02:00
parent 924412f66f 6b1859dba0
commit e8b9dd7e24
1128 changed files with 11467 additions and 6098 deletions
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36
kernel/cgroup.c
View File

@@ -255,12 +255,17 @@ int cgroup_lock_is_held(void)
EXPORT_SYMBOL_GPL(cgroup_lock_is_held);
static int css_unbias_refcnt(int refcnt)
{
return refcnt >= 0 ? refcnt : refcnt - CSS_DEACT_BIAS;
}
/* the current nr of refs, always >= 0 whether @css is deactivated or not */
static int css_refcnt(struct cgroup_subsys_state *css)
{
int v = atomic_read(&css->refcnt);
return v >= 0 ? v : v - CSS_DEACT_BIAS;
return css_unbias_refcnt(v);
}
/* convenient tests for these bits */
@@ -896,13 +901,10 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
mutex_unlock(&cgroup_mutex);
/*
* We want to drop the active superblock reference from the
* cgroup creation after all the dentry refs are gone -
* kill_sb gets mighty unhappy otherwise. Mark
* dentry->d_fsdata with cgroup_diput() to tell
* cgroup_d_release() to call deactivate_super().
* Drop the active superblock reference that we took when we
* created the cgroup
*/
dentry->d_fsdata = cgroup_diput;
deactivate_super(cgrp->root->sb);
/*
* if we're getting rid of the cgroup, refcount should ensure
@@ -928,13 +930,6 @@ static int cgroup_delete(const struct dentry *d)
return 1;
}
static void cgroup_d_release(struct dentry *dentry)
{
/* did cgroup_diput() tell me to deactivate super? */
if (dentry->d_fsdata == cgroup_diput)
deactivate_super(dentry->d_sb);
}
static void remove_dir(struct dentry *d)
{
struct dentry *parent = dget(d->d_parent);
@@ -1542,7 +1537,6 @@ static int cgroup_get_rootdir(struct super_block *sb)
static const struct dentry_operations cgroup_dops = {
.d_iput = cgroup_diput,
.d_delete = cgroup_delete,
.d_release = cgroup_d_release,
};
struct inode *inode =
@@ -3889,8 +3883,12 @@ static void css_dput_fn(struct work_struct *work)
{
struct cgroup_subsys_state *css =
container_of(work, struct cgroup_subsys_state, dput_work);
struct dentry *dentry = css->cgroup->dentry;
struct super_block *sb = dentry->d_sb;
dput(css->cgroup->dentry);
atomic_inc(&sb->s_active);
dput(dentry);
deactivate_super(sb);
}
static void init_cgroup_css(struct cgroup_subsys_state *css,
@@ -4982,10 +4980,12 @@ EXPORT_SYMBOL_GPL(__css_tryget);
void __css_put(struct cgroup_subsys_state *css)
{
struct cgroup *cgrp = css->cgroup;
int v;
rcu_read_lock();
atomic_dec(&css->refcnt);
switch (css_refcnt(css)) {
v = css_unbias_refcnt(atomic_dec_return(&css->refcnt));
switch (v) {
case 1:
if (notify_on_release(cgrp)) {
set_bit(CGRP_RELEASABLE, &cgrp->flags);

10
kernel/events/core.c
View File

@@ -253,9 +253,9 @@ perf_cgroup_match(struct perf_event *event)
return !event->cgrp || event->cgrp == cpuctx->cgrp;
}
static inline void perf_get_cgroup(struct perf_event *event)
static inline bool perf_tryget_cgroup(struct perf_event *event)
{
css_get(&event->cgrp->css);
return css_tryget(&event->cgrp->css);
}
static inline void perf_put_cgroup(struct perf_event *event)
@@ -484,7 +484,11 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
event->cgrp = cgrp;
/* must be done before we fput() the file */
perf_get_cgroup(event);
if (!perf_tryget_cgroup(event)) {
event->cgrp = NULL;
ret = -ENOENT;
goto out;
}
/*
* all events in a group must monitor

19
kernel/exit.c
View File

@@ -72,6 +72,18 @@ static void __unhash_process(struct task_struct *p, bool group_dead)
list_del_rcu(&p->tasks);
list_del_init(&p->sibling);
__this_cpu_dec(process_counts);
/*
* If we are the last child process in a pid namespace to be
* reaped, notify the reaper sleeping zap_pid_ns_processes().
*/
if (IS_ENABLED(CONFIG_PID_NS)) {
struct task_struct *parent = p->real_parent;
if ((task_active_pid_ns(parent)->child_reaper == parent) &&
list_empty(&parent->children) &&
(parent->flags & PF_EXITING))
wake_up_process(parent);
}
}
list_del_rcu(&p->thread_group);
}
@@ -643,6 +655,7 @@ static void exit_mm(struct task_struct * tsk)
mm_release(tsk, mm);
if (!mm)
return;
sync_mm_rss(mm);
/*
* Serialize with any possible pending coredump.
* We must hold mmap_sem around checking core_state
@@ -719,12 +732,6 @@ static struct task_struct *find_new_reaper(struct task_struct *father)
zap_pid_ns_processes(pid_ns);
write_lock_irq(&tasklist_lock);
/*
* We can not clear ->child_reaper or leave it alone.
* There may by stealth EXIT_DEAD tasks on ->children,
* forget_original_parent() must move them somewhere.
*/
pid_ns->child_reaper = init_pid_ns.child_reaper;
} else if (father->signal->has_child_subreaper) {
struct task_struct *reaper;

11
kernel/fork.c
View File

@@ -304,12 +304,17 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
}
err = arch_dup_task_struct(tsk, orig);
/*
* We defer looking at err, because we will need this setup
* for the clean up path to work correctly.
*/
tsk->stack = ti;
setup_thread_stack(tsk, orig);
if (err)
goto out;
tsk->stack = ti;
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
clear_tsk_need_resched(tsk);
stackend = end_of_stack(tsk);

53
kernel/hrtimer.c
View File

@@ -657,6 +657,14 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
return 0;
}
static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
{
ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset;
ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset;
return ktime_get_update_offsets(offs_real, offs_boot);
}
/*
* Retrigger next event is called after clock was set
*
@@ -665,22 +673,12 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
static void retrigger_next_event(void *arg)
{
struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases);
struct timespec realtime_offset, xtim, wtm, sleep;
if (!hrtimer_hres_active())
return;
/* Optimized out for !HIGH_RES */
get_xtime_and_monotonic_and_sleep_offset(&xtim, &wtm, &sleep);
set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec);
/* Adjust CLOCK_REALTIME offset */
raw_spin_lock(&base->lock);
base->clock_base[HRTIMER_BASE_REALTIME].offset =
timespec_to_ktime(realtime_offset);
base->clock_base[HRTIMER_BASE_BOOTTIME].offset =
timespec_to_ktime(sleep);
hrtimer_update_base(base);
hrtimer_force_reprogram(base, 0);
raw_spin_unlock(&base->lock);
}
@@ -710,13 +708,25 @@ static int hrtimer_switch_to_hres(void)
base->clock_base[i].resolution = KTIME_HIGH_RES;
tick_setup_sched_timer();
/* "Retrigger" the interrupt to get things going */
retrigger_next_event(NULL);
local_irq_restore(flags);
return 1;
}
/*
* Called from timekeeping code to reprogramm the hrtimer interrupt
* device. If called from the timer interrupt context we defer it to
* softirq context.
*/
void clock_was_set_delayed(void)
{
struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
cpu_base->clock_was_set = 1;
__raise_softirq_irqoff(HRTIMER_SOFTIRQ);
}
#else
static inline int hrtimer_hres_active(void) { return 0; }
@@ -1250,11 +1260,10 @@ void hrtimer_interrupt(struct clock_event_device *dev)
cpu_base->nr_events++;
dev->next_event.tv64 = KTIME_MAX;
entry_time = now = ktime_get();
raw_spin_lock(&cpu_base->lock);
entry_time = now = hrtimer_update_base(cpu_base);
retry:
expires_next.tv64 = KTIME_MAX;
raw_spin_lock(&cpu_base->lock);
/*
* We set expires_next to KTIME_MAX here with cpu_base->lock
* held to prevent that a timer is enqueued in our queue via
@@ -1330,8 +1339,12 @@ retry:
* We need to prevent that we loop forever in the hrtimer
* interrupt routine. We give it 3 attempts to avoid
* overreacting on some spurious event.
*
* Acquire base lock for updating the offsets and retrieving
* the current time.
*/
now = ktime_get();
raw_spin_lock(&cpu_base->lock);
now = hrtimer_update_base(cpu_base);
cpu_base->nr_retries++;
if (++retries < 3)
goto retry;
@@ -1343,6 +1356,7 @@ retry:
*/
cpu_base->nr_hangs++;
cpu_base->hang_detected = 1;
raw_spin_unlock(&cpu_base->lock);
delta = ktime_sub(now, entry_time);
if (delta.tv64 > cpu_base->max_hang_time.tv64)
cpu_base->max_hang_time = delta;
@@ -1395,6 +1409,13 @@ void hrtimer_peek_ahead_timers(void)
static void run_hrtimer_softirq(struct softirq_action *h)
{
struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
if (cpu_base->clock_was_set) {
cpu_base->clock_was_set = 0;
clock_was_set();
}
hrtimer_peek_ahead_timers();
}

6
kernel/panic.c
View File

@@ -27,7 +27,7 @@
#define PANIC_TIMER_STEP 100
#define PANIC_BLINK_SPD 18
int panic_on_oops;
int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
static unsigned long tainted_mask;
static int pause_on_oops;
static int pause_on_oops_flag;
@@ -108,8 +108,6 @@ void panic(const char *fmt, ...)
*/
crash_kexec(NULL);
kmsg_dump(KMSG_DUMP_PANIC);
/*
* Note smp_send_stop is the usual smp shutdown function, which
* unfortunately means it may not be hardened to work in a panic
@@ -117,6 +115,8 @@ void panic(const char *fmt, ...)
*/
smp_send_stop();
kmsg_dump(KMSG_DUMP_PANIC);
atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
bust_spinlocks(0);

20
kernel/pid_namespace.c
View File

@@ -184,11 +184,31 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
}
read_unlock(&tasklist_lock);
/* Firstly reap the EXIT_ZOMBIE children we may have. */
do {
clear_thread_flag(TIF_SIGPENDING);
rc = sys_wait4(-1, NULL, __WALL, NULL);
} while (rc != -ECHILD);
/*
* sys_wait4() above can't reap the TASK_DEAD children.
* Make sure they all go away, see __unhash_process().
*/
for (;;) {
bool need_wait = false;
read_lock(&tasklist_lock);
if (!list_empty(&current->children)) {
__set_current_state(TASK_UNINTERRUPTIBLE);
need_wait = true;
}
read_unlock(&tasklist_lock);
if (!need_wait)
break;
schedule();
}
if (pid_ns->reboot)
current->signal->group_exit_code = pid_ns->reboot;

684
kernel/printk.c
View File

File diff suppressed because it is too large Load Diff

17
kernel/rcutree.c
View File

@@ -201,6 +201,7 @@ void rcu_note_context_switch(int cpu)
{
trace_rcu_utilization("Start context switch");
rcu_sched_qs(cpu);
rcu_preempt_note_context_switch(cpu);
trace_rcu_utilization("End context switch");
}
EXPORT_SYMBOL_GPL(rcu_note_context_switch);
@@ -1397,6 +1398,8 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
rdp->qlen_lazy += rsp->qlen_lazy;
rdp->qlen += rsp->qlen;
rdp->n_cbs_adopted += rsp->qlen;
if (rsp->qlen_lazy != rsp->qlen)
rcu_idle_count_callbacks_posted();
rsp->qlen_lazy = 0;
rsp->qlen = 0;
@@ -1528,7 +1531,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
{
unsigned long flags;
struct rcu_head *next, *list, **tail;
int bl, count, count_lazy;
int bl, count, count_lazy, i;
/* If no callbacks are ready, just return.*/
if (!cpu_has_callbacks_ready_to_invoke(rdp)) {
@@ -1551,9 +1554,9 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
rdp->nxtlist = *rdp->nxttail[RCU_DONE_TAIL];
*rdp->nxttail[RCU_DONE_TAIL] = NULL;
tail = rdp->nxttail[RCU_DONE_TAIL];
for (count = RCU_NEXT_SIZE - 1; count >= 0; count--)
if (rdp->nxttail[count] == rdp->nxttail[RCU_DONE_TAIL])
rdp->nxttail[count] = &rdp->nxtlist;
for (i = RCU_NEXT_SIZE - 1; i >= 0; i--)
if (rdp->nxttail[i] == rdp->nxttail[RCU_DONE_TAIL])
rdp->nxttail[i] = &rdp->nxtlist;
local_irq_restore(flags);
/* Invoke callbacks. */
@@ -1581,9 +1584,9 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
if (list != NULL) {
*tail = rdp->nxtlist;
rdp->nxtlist = list;
for (count = 0; count < RCU_NEXT_SIZE; count++)
if (&rdp->nxtlist == rdp->nxttail[count])
rdp->nxttail[count] = tail;
for (i = 0; i < RCU_NEXT_SIZE; i++)
if (&rdp->nxtlist == rdp->nxttail[i])
rdp->nxttail[i] = tail;
else
break;
}

15
kernel/rcutree.h
View File

@@ -84,6 +84,20 @@ struct rcu_dynticks {
/* Process level is worth LLONG_MAX/2. */
int dynticks_nmi_nesting; /* Track NMI nesting level. */
atomic_t dynticks; /* Even value for idle, else odd. */
#ifdef CONFIG_RCU_FAST_NO_HZ
int dyntick_drain; /* Prepare-for-idle state variable. */
unsigned long dyntick_holdoff;
/* No retries for the jiffy of failure. */
struct timer_list idle_gp_timer;
/* Wake up CPU sleeping with callbacks. */
unsigned long idle_gp_timer_expires;
/* When to wake up CPU (for repost). */
bool idle_first_pass; /* First pass of attempt to go idle? */
unsigned long nonlazy_posted;
/* # times non-lazy CBs posted to CPU. */
unsigned long nonlazy_posted_snap;
/* idle-period nonlazy_posted snapshot. */
#endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
};
/* RCU's kthread states for tracing. */
@@ -430,6 +444,7 @@ DECLARE_PER_CPU(char, rcu_cpu_has_work);
/* Forward declarations for rcutree_plugin.h */
static void rcu_bootup_announce(void);
long rcu_batches_completed(void);
static void rcu_preempt_note_context_switch(int cpu);
static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp);
#ifdef CONFIG_HOTPLUG_CPU
static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,

179
kernel/rcutree_plugin.h
View File

@@ -153,7 +153,7 @@ static void rcu_preempt_qs(int cpu)
*
* Caller must disable preemption.
*/
void rcu_preempt_note_context_switch(void)
static void rcu_preempt_note_context_switch(int cpu)
{
struct task_struct *t = current;
unsigned long flags;
@@ -164,7 +164,7 @@ void rcu_preempt_note_context_switch(void)
(t->rcu_read_unlock_special & RCU_READ_UNLOCK_BLOCKED) == 0) {
/* Possibly blocking in an RCU read-side critical section. */
rdp = __this_cpu_ptr(rcu_preempt_state.rda);
rdp = per_cpu_ptr(rcu_preempt_state.rda, cpu);
rnp = rdp->mynode;
raw_spin_lock_irqsave(&rnp->lock, flags);
t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED;
@@ -228,7 +228,7 @@ void rcu_preempt_note_context_switch(void)
* means that we continue to block the current grace period.
*/
local_irq_save(flags);
rcu_preempt_qs(smp_processor_id());
rcu_preempt_qs(cpu);
local_irq_restore(flags);
}
@@ -1001,6 +1001,14 @@ void rcu_force_quiescent_state(void)
}
EXPORT_SYMBOL_GPL(rcu_force_quiescent_state);
/*
* Because preemptible RCU does not exist, we never have to check for
* CPUs being in quiescent states.
*/
static void rcu_preempt_note_context_switch(int cpu)
{
}
/*
* Because preemptible RCU does not exist, there are never any preempted
* RCU readers.
@@ -1886,8 +1894,9 @@ static void __cpuinit rcu_prepare_kthreads(int cpu)
* Because we not have RCU_FAST_NO_HZ, just check whether this CPU needs
* any flavor of RCU.
*/
int rcu_needs_cpu(int cpu)
int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
{
*delta_jiffies = ULONG_MAX;
return rcu_cpu_has_callbacks(cpu);
}
@@ -1962,41 +1971,6 @@ static void rcu_idle_count_callbacks_posted(void)
#define RCU_IDLE_GP_DELAY 6 /* Roughly one grace period. */
#define RCU_IDLE_LAZY_GP_DELAY (6 * HZ) /* Roughly six seconds. */
/* Loop counter for rcu_prepare_for_idle(). */
static DEFINE_PER_CPU(int, rcu_dyntick_drain);
/* If rcu_dyntick_holdoff==jiffies, don't try to enter dyntick-idle mode. */
static DEFINE_PER_CPU(unsigned long, rcu_dyntick_holdoff);
/* Timer to awaken the CPU if it enters dyntick-idle mode with callbacks. */
static DEFINE_PER_CPU(struct timer_list, rcu_idle_gp_timer);
/* Scheduled expiry time for rcu_idle_gp_timer to allow reposting. */
static DEFINE_PER_CPU(unsigned long, rcu_idle_gp_timer_expires);
/* Enable special processing on first attempt to enter dyntick-idle mode. */
static DEFINE_PER_CPU(bool, rcu_idle_first_pass);
/* Running count of non-lazy callbacks posted, never decremented. */
static DEFINE_PER_CPU(unsigned long, rcu_nonlazy_posted);
/* Snapshot of rcu_nonlazy_posted to detect meaningful exits from idle. */
static DEFINE_PER_CPU(unsigned long, rcu_nonlazy_posted_snap);
/*
* Allow the CPU to enter dyntick-idle mode if either: (1) There are no
* callbacks on this CPU, (2) this CPU has not yet attempted to enter
* dyntick-idle mode, or (3) this CPU is in the process of attempting to
* enter dyntick-idle mode. Otherwise, if we have recently tried and failed
* to enter dyntick-idle mode, we refuse to try to enter it. After all,
* it is better to incur scheduling-clock interrupts than to spin
* continuously for the same time duration!
*/
int rcu_needs_cpu(int cpu)
{
/* Flag a new idle sojourn to the idle-entry state machine. */
per_cpu(rcu_idle_first_pass, cpu) = 1;
/* If no callbacks, RCU doesn't need the CPU. */
if (!rcu_cpu_has_callbacks(cpu))
return 0;
/* Otherwise, RCU needs the CPU only if it recently tried and failed. */
return per_cpu(rcu_dyntick_holdoff, cpu) == jiffies;
}
/*
* Does the specified flavor of RCU have non-lazy callbacks pending on
* the specified CPU? Both RCU flavor and CPU are specified by the
@@ -2039,6 +2013,47 @@ static bool rcu_cpu_has_nonlazy_callbacks(int cpu)
rcu_preempt_cpu_has_nonlazy_callbacks(cpu);
}
/*
* Allow the CPU to enter dyntick-idle mode if either: (1) There are no
* callbacks on this CPU, (2) this CPU has not yet attempted to enter
* dyntick-idle mode, or (3) this CPU is in the process of attempting to
* enter dyntick-idle mode. Otherwise, if we have recently tried and failed
* to enter dyntick-idle mode, we refuse to try to enter it. After all,
* it is better to incur scheduling-clock interrupts than to spin
* continuously for the same time duration!
*
* The delta_jiffies argument is used to store the time when RCU is
* going to need the CPU again if it still has callbacks. The reason
* for this is that rcu_prepare_for_idle() might need to post a timer,
* but if so, it will do so after tick_nohz_stop_sched_tick() has set
* the wakeup time for this CPU. This means that RCU's timer can be
* delayed until the wakeup time, which defeats the purpose of posting
* a timer.
*/
int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
{
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
/* Flag a new idle sojourn to the idle-entry state machine. */
rdtp->idle_first_pass = 1;
/* If no callbacks, RCU doesn't need the CPU. */
if (!rcu_cpu_has_callbacks(cpu)) {
*delta_jiffies = ULONG_MAX;
return 0;
}
if (rdtp->dyntick_holdoff == jiffies) {
/* RCU recently tried and failed, so don't try again. */
*delta_jiffies = 1;
return 1;
}
/* Set up for the possibility that RCU will post a timer. */
if (rcu_cpu_has_nonlazy_callbacks(cpu))
*delta_jiffies = RCU_IDLE_GP_DELAY;
else
*delta_jiffies = RCU_IDLE_LAZY_GP_DELAY;
return 0;
}
/*
* Handler for smp_call_function_single(). The only point of this
* handler is to wake the CPU up, so the handler does only tracing.
@@ -2075,21 +2090,24 @@ static void rcu_idle_gp_timer_func(unsigned long cpu_in)
*/
static void rcu_prepare_for_idle_init(int cpu)
{
per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1;
setup_timer(&per_cpu(rcu_idle_gp_timer, cpu),
rcu_idle_gp_timer_func, cpu);
per_cpu(rcu_idle_gp_timer_expires, cpu) = jiffies - 1;
per_cpu(rcu_idle_first_pass, cpu) = 1;
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
rdtp->dyntick_holdoff = jiffies - 1;
setup_timer(&rdtp->idle_gp_timer, rcu_idle_gp_timer_func, cpu);
rdtp->idle_gp_timer_expires = jiffies - 1;
rdtp->idle_first_pass = 1;
}
/*
* Clean up for exit from idle. Because we are exiting from idle, there
* is no longer any point to rcu_idle_gp_timer, so cancel it. This will
* is no longer any point to ->idle_gp_timer, so cancel it. This will
* do nothing if this timer is not active, so just cancel it unconditionally.
*/
static void rcu_cleanup_after_idle(int cpu)
{
del_timer(&per_cpu(rcu_idle_gp_timer, cpu));
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
del_timer(&rdtp->idle_gp_timer);
trace_rcu_prep_idle("Cleanup after idle");
}
@@ -2108,42 +2126,41 @@ static void rcu_cleanup_after_idle(int cpu)
* Because it is not legal to invoke rcu_process_callbacks() with irqs
* disabled, we do one pass of force_quiescent_state(), then do a
* invoke_rcu_core() to cause rcu_process_callbacks() to be invoked
* later. The per-cpu rcu_dyntick_drain variable controls the sequencing.
* later. The ->dyntick_drain field controls the sequencing.
*
* The caller must have disabled interrupts.
*/
static void rcu_prepare_for_idle(int cpu)
{
struct timer_list *tp;
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
/*
* If this is an idle re-entry, for example, due to use of
* RCU_NONIDLE() or the new idle-loop tracing API within the idle
* loop, then don't take any state-machine actions, unless the
* momentary exit from idle queued additional non-lazy callbacks.
* Instead, repost the rcu_idle_gp_timer if this CPU has callbacks
* Instead, repost the ->idle_gp_timer if this CPU has callbacks
* pending.
*/
if (!per_cpu(rcu_idle_first_pass, cpu) &&
(per_cpu(rcu_nonlazy_posted, cpu) ==
per_cpu(rcu_nonlazy_posted_snap, cpu))) {
if (!rdtp->idle_first_pass &&
(rdtp->nonlazy_posted == rdtp->nonlazy_posted_snap)) {
if (rcu_cpu_has_callbacks(cpu)) {
tp = &per_cpu(rcu_idle_gp_timer, cpu);
mod_timer_pinned(tp, per_cpu(rcu_idle_gp_timer_expires, cpu));
tp = &rdtp->idle_gp_timer;
mod_timer_pinned(tp, rdtp->idle_gp_timer_expires);
}
return;
}
per_cpu(rcu_idle_first_pass, cpu) = 0;
per_cpu(rcu_nonlazy_posted_snap, cpu) =
per_cpu(rcu_nonlazy_posted, cpu) - 1;
rdtp->idle_first_pass = 0;
rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted - 1;
/*
* If there are no callbacks on this CPU, enter dyntick-idle mode.
* Also reset state to avoid prejudicing later attempts.
*/
if (!rcu_cpu_has_callbacks(cpu)) {
per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1;
per_cpu(rcu_dyntick_drain, cpu) = 0;
rdtp->dyntick_holdoff = jiffies - 1;
rdtp->dyntick_drain = 0;
trace_rcu_prep_idle("No callbacks");
return;
}
@@ -2152,36 +2169,37 @@ static void rcu_prepare_for_idle(int cpu)
* If in holdoff mode, just return. We will presumably have
* refrained from disabling the scheduling-clock tick.
*/
if (per_cpu(rcu_dyntick_holdoff, cpu) == jiffies) {
if (rdtp->dyntick_holdoff == jiffies) {
trace_rcu_prep_idle("In holdoff");
return;
}
/* Check and update the rcu_dyntick_drain sequencing. */
if (per_cpu(rcu_dyntick_drain, cpu) <= 0) {
/* Check and update the ->dyntick_drain sequencing. */
if (rdtp->dyntick_drain <= 0) {
/* First time through, initialize the counter. */
per_cpu(rcu_dyntick_drain, cpu) = RCU_IDLE_FLUSHES;
} else if (per_cpu(rcu_dyntick_drain, cpu) <= RCU_IDLE_OPT_FLUSHES &&
rdtp->dyntick_drain = RCU_IDLE_FLUSHES;
} else if (rdtp->dyntick_drain <= RCU_IDLE_OPT_FLUSHES &&
!rcu_pending(cpu) &&
!local_softirq_pending()) {
/* Can we go dyntick-idle despite still having callbacks? */
trace_rcu_prep_idle("Dyntick with callbacks");
per_cpu(rcu_dyntick_drain, cpu) = 0;
per_cpu(rcu_dyntick_holdoff, cpu) = jiffies;
if (rcu_cpu_has_nonlazy_callbacks(cpu))
per_cpu(rcu_idle_gp_timer_expires, cpu) =
rdtp->dyntick_drain = 0;
rdtp->dyntick_holdoff = jiffies;
if (rcu_cpu_has_nonlazy_callbacks(cpu)) {
trace_rcu_prep_idle("Dyntick with callbacks");
rdtp->idle_gp_timer_expires =
jiffies + RCU_IDLE_GP_DELAY;
else
per_cpu(rcu_idle_gp_timer_expires, cpu) =
} else {
rdtp->idle_gp_timer_expires =
jiffies + RCU_IDLE_LAZY_GP_DELAY;
tp = &per_cpu(rcu_idle_gp_timer, cpu);
mod_timer_pinned(tp, per_cpu(rcu_idle_gp_timer_expires, cpu));
per_cpu(rcu_nonlazy_posted_snap, cpu) =
per_cpu(rcu_nonlazy_posted, cpu);
trace_rcu_prep_idle("Dyntick with lazy callbacks");
}
tp = &rdtp->idle_gp_timer;
mod_timer_pinned(tp, rdtp->idle_gp_timer_expires);
rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted;
return; /* Nothing more to do immediately. */
} else if (--per_cpu(rcu_dyntick_drain, cpu) <= 0) {
} else if (--(rdtp->dyntick_drain) <= 0) {
/* We have hit the limit, so time to give up. */
per_cpu(rcu_dyntick_holdoff, cpu) = jiffies;
rdtp->dyntick_holdoff = jiffies;
trace_rcu_prep_idle("Begin holdoff");
invoke_rcu_core(); /* Force the CPU out of dyntick-idle. */
return;
@@ -2227,7 +2245,7 @@ static void rcu_prepare_for_idle(int cpu)
*/
static void rcu_idle_count_callbacks_posted(void)
{
__this_cpu_add(rcu_nonlazy_posted, 1);
__this_cpu_add(rcu_dynticks.nonlazy_posted, 1);
}
#endif /* #else #if !defined(CONFIG_RCU_FAST_NO_HZ) */
@@ -2238,11 +2256,12 @@ static void rcu_idle_count_callbacks_posted(void)
static void print_cpu_stall_fast_no_hz(char *cp, int cpu)
{
struct timer_list *tltp = &per_cpu(rcu_idle_gp_timer, cpu);
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
struct timer_list *tltp = &rdtp->idle_gp_timer;
sprintf(cp, "drain=%d %c timer=%lu",
per_cpu(rcu_dyntick_drain, cpu),
per_cpu(rcu_dyntick_holdoff, cpu) == jiffies ? 'H' : '.',
rdtp->dyntick_drain,
rdtp->dyntick_holdoff == jiffies ? 'H' : '.',
timer_pending(tltp) ? tltp->expires - jiffies : -1);
}

5
kernel/relay.c
View File

@@ -1235,6 +1235,7 @@ static ssize_t subbuf_splice_actor(struct file *in,
struct splice_pipe_desc spd = {
.pages = pages,
.nr_pages = 0,
.nr_pages_max = PIPE_DEF_BUFFERS,
.partial = partial,
.flags = flags,
.ops = &relay_pipe_buf_ops,
@@ -1302,8 +1303,8 @@ static ssize_t subbuf_splice_actor(struct file *in,
ret += padding;
out:
splice_shrink_spd(pipe, &spd);
return ret;
splice_shrink_spd(&spd);
return ret;
}
static ssize_t relay_file_splice_read(struct file *in,

278
kernel/sched/core.c
View File

@@ -2081,7 +2081,6 @@ context_switch(struct rq *rq, struct task_struct *prev,
#endif
/* Here we just switch the register state and the stack. */
rcu_switch_from(prev);
switch_to(prev, next, prev);
barrier();
@@ -2161,11 +2160,73 @@ unsigned long this_cpu_load(void)
}
/*
* Global load-average calculations
*
* We take a distributed and async approach to calculating the global load-avg
* in order to minimize overhead.
*
* The global load average is an exponentially decaying average of nr_running +
* nr_uninterruptible.
*
* Once every LOAD_FREQ:
*
* nr_active = 0;
* for_each_possible_cpu(cpu)
* nr_active += cpu_of(cpu)->nr_running + cpu_of(cpu)->nr_uninterruptible;
*
* avenrun[n] = avenrun[0] * exp_n + nr_active * (1 - exp_n)
*
* Due to a number of reasons the above turns in the mess below:
*
* - for_each_possible_cpu() is prohibitively expensive on machines with
* serious number of cpus, therefore we need to take a distributed approach
* to calculating nr_active.
*
* \Sum_i x_i(t) = \Sum_i x_i(t) - x_i(t_0) | x_i(t_0) := 0
* = \Sum_i { \Sum_j=1 x_i(t_j) - x_i(t_j-1) }
*
* So assuming nr_active := 0 when we start out -- true per definition, we
* can simply take per-cpu deltas and fold those into a global accumulate
* to obtain the same result. See calc_load_fold_active().
*
* Furthermore, in order to avoid synchronizing all per-cpu delta folding
* across the machine, we assume 10 ticks is sufficient time for every
* cpu to have completed this task.
*
* This places an upper-bound on the IRQ-off latency of the machine. Then
* again, being late doesn't loose the delta, just wrecks the sample.
*
* - cpu_rq()->nr_uninterruptible isn't accurately tracked per-cpu because
* this would add another cross-cpu cacheline miss and atomic operation
* to the wakeup path. Instead we increment on whatever cpu the task ran
* when it went into uninterruptible state and decrement on whatever cpu
* did the wakeup. This means that only the sum of nr_uninterruptible over
* all cpus yields the correct result.
*
* This covers the NO_HZ=n code, for extra head-aches, see the comment below.
*/
/* Variables and functions for calc_load */
static atomic_long_t calc_load_tasks;
static unsigned long calc_load_update;
unsigned long avenrun[3];
EXPORT_SYMBOL(avenrun);
EXPORT_SYMBOL(avenrun); /* should be removed */
/**
* get_avenrun - get the load average array
* @loads: pointer to dest load array
* @offset: offset to add
* @shift: shift count to shift the result left
*
* These values are estimates at best, so no need for locking.
*/
void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
{
loads[0] = (avenrun[0] + offset) << shift;
loads[1] = (avenrun[1] + offset) << shift;
loads[2] = (avenrun[2] + offset) << shift;
}
static long calc_load_fold_active(struct rq *this_rq)
{
@@ -2182,6 +2243,9 @@ static long calc_load_fold_active(struct rq *this_rq)
return delta;
}
/*
* a1 = a0 * e + a * (1 - e)
*/
static unsigned long
calc_load(unsigned long load, unsigned long exp, unsigned long active)
{
@@ -2193,30 +2257,118 @@ calc_load(unsigned long load, unsigned long exp, unsigned long active)
#ifdef CONFIG_NO_HZ
/*
* For NO_HZ we delay the active fold to the next LOAD_FREQ update.
* Handle NO_HZ for the global load-average.
*
* Since the above described distributed algorithm to compute the global
* load-average relies on per-cpu sampling from the tick, it is affected by
* NO_HZ.
*
* The basic idea is to fold the nr_active delta into a global idle-delta upon
* entering NO_HZ state such that we can include this as an 'extra' cpu delta
* when we read the global state.
*
* Obviously reality has to ruin such a delightfully simple scheme:
*
* - When we go NO_HZ idle during the window, we can negate our sample
* contribution, causing under-accounting.
*
* We avoid this by keeping two idle-delta counters and flipping them
* when the window starts, thus separating old and new NO_HZ load.
*
* The only trick is the slight shift in index flip for read vs write.
*
* 0s 5s 10s 15s
* +10 +10 +10 +10
* |-|-----------|-|-----------|-|-----------|-|
* r:0 0 1 1 0 0 1 1 0
* w:0 1 1 0 0 1 1 0 0
*
* This ensures we'll fold the old idle contribution in this window while
* accumlating the new one.
*
* - When we wake up from NO_HZ idle during the window, we push up our
* contribution, since we effectively move our sample point to a known
* busy state.
*
* This is solved by pushing the window forward, and thus skipping the
* sample, for this cpu (effectively using the idle-delta for this cpu which
* was in effect at the time the window opened). This also solves the issue
* of having to deal with a cpu having been in NOHZ idle for multiple
* LOAD_FREQ intervals.
*
* When making the ILB scale, we should try to pull this in as well.
*/
static atomic_long_t calc_load_tasks_idle;
static atomic_long_t calc_load_idle[2];
static int calc_load_idx;
void calc_load_account_idle(struct rq *this_rq)
static inline int calc_load_write_idx(void)
{
int idx = calc_load_idx;
/*
* See calc_global_nohz(), if we observe the new index, we also
* need to observe the new update time.
*/
smp_rmb();
/*
* If the folding window started, make sure we start writing in the
* next idle-delta.
*/
if (!time_before(jiffies, calc_load_update))
idx++;
return idx & 1;
}
static inline int calc_load_read_idx(void)
{
return calc_load_idx & 1;
}
void calc_load_enter_idle(void)
{
struct rq *this_rq = this_rq();
long delta;
/*
* We're going into NOHZ mode, if there's any pending delta, fold it
* into the pending idle delta.
*/
delta = calc_load_fold_active(this_rq);
if (delta)
atomic_long_add(delta, &calc_load_tasks_idle);
if (delta) {
int idx = calc_load_write_idx();
atomic_long_add(delta, &calc_load_idle[idx]);
}
}
void calc_load_exit_idle(void)
{
struct rq *this_rq = this_rq();
/*
* If we're still before the sample window, we're done.
*/
if (time_before(jiffies, this_rq->calc_load_update))
return;
/*
* We woke inside or after the sample window, this means we're already
* accounted through the nohz accounting, so skip the entire deal and
* sync up for the next window.
*/
this_rq->calc_load_update = calc_load_update;
if (time_before(jiffies, this_rq->calc_load_update + 10))
this_rq->calc_load_update += LOAD_FREQ;
}
static long calc_load_fold_idle(void)
{
int idx = calc_load_read_idx();
long delta = 0;
/*
* Its got a race, we don't care...
*/
if (atomic_long_read(&calc_load_tasks_idle))
delta = atomic_long_xchg(&calc_load_tasks_idle, 0);
if (atomic_long_read(&calc_load_idle[idx]))
delta = atomic_long_xchg(&calc_load_idle[idx], 0);
return delta;
}
@@ -2302,66 +2454,39 @@ static void calc_global_nohz(void)
{
long delta, active, n;
/*
* If we crossed a calc_load_update boundary, make sure to fold
* any pending idle changes, the respective CPUs might have
* missed the tick driven calc_load_account_active() update
* due to NO_HZ.
*/
delta = calc_load_fold_idle();
if (delta)
atomic_long_add(delta, &calc_load_tasks);
if (!time_before(jiffies, calc_load_update + 10)) {
/*
* Catch-up, fold however many we are behind still
*/
delta = jiffies - calc_load_update - 10;
n = 1 + (delta / LOAD_FREQ);
active = atomic_long_read(&calc_load_tasks);
active = active > 0 ? active * FIXED_1 : 0;
avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
calc_load_update += n * LOAD_FREQ;
}
/*
* It could be the one fold was all it took, we done!
* Flip the idle index...
*
* Make sure we first write the new time then flip the index, so that
* calc_load_write_idx() will see the new time when it reads the new
* index, this avoids a double flip messing things up.
*/
if (time_before(jiffies, calc_load_update + 10))
return;
/*
* Catch-up, fold however many we are behind still
*/
delta = jiffies - calc_load_update - 10;
n = 1 + (delta / LOAD_FREQ);
active = atomic_long_read(&calc_load_tasks);
active = active > 0 ? active * FIXED_1 : 0;
avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
calc_load_update += n * LOAD_FREQ;
}
#else
void calc_load_account_idle(struct rq *this_rq)
{
smp_wmb();
calc_load_idx++;
}
#else /* !CONFIG_NO_HZ */
static inline long calc_load_fold_idle(void)
{
return 0;
}
static inline long calc_load_fold_idle(void) { return 0; }
static inline void calc_global_nohz(void) { }
static void calc_global_nohz(void)
{
}
#endif
/**
* get_avenrun - get the load average array
* @loads: pointer to dest load array
* @offset: offset to add
* @shift: shift count to shift the result left
*
* These values are estimates at best, so no need for locking.
*/
void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
{
loads[0] = (avenrun[0] + offset) << shift;
loads[1] = (avenrun[1] + offset) << shift;
loads[2] = (avenrun[2] + offset) << shift;
}
#endif /* CONFIG_NO_HZ */
/*
* calc_load - update the avenrun load estimates 10 ticks after the
@@ -2369,11 +2494,18 @@ void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
*/
void calc_global_load(unsigned long ticks)
{
long active;
long active, delta;
if (time_before(jiffies, calc_load_update + 10))
return;
/*
* Fold the 'old' idle-delta to include all NO_HZ cpus.
*/
delta = calc_load_fold_idle();
if (delta)
atomic_long_add(delta, &calc_load_tasks);
active = atomic_long_read(&calc_load_tasks);
active = active > 0 ? active * FIXED_1 : 0;
@@ -2384,12 +2516,7 @@ void calc_global_load(unsigned long ticks)
calc_load_update += LOAD_FREQ;
/*
* Account one period with whatever state we found before
* folding in the nohz state and ageing the entire idle period.
*
* This avoids loosing a sample when we go idle between
* calc_load_account_active() (10 ticks ago) and now and thus
* under-accounting.
* In case we idled for multiple LOAD_FREQ intervals, catch up in bulk.
*/
calc_global_nohz();
}
@@ -2406,13 +2533,16 @@ static void calc_load_account_active(struct rq *this_rq)
return;
delta = calc_load_fold_active(this_rq);
delta += calc_load_fold_idle();
if (delta)
atomic_long_add(delta, &calc_load_tasks);
this_rq->calc_load_update += LOAD_FREQ;
}
/*
* End of global load-average stuff
*/
/*
* The exact cpuload at various idx values, calculated at every tick would be
* load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load

1
kernel/sched/idle_task.c
View File

@@ -25,7 +25,6 @@ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int fl
static struct task_struct *pick_next_task_idle(struct rq *rq)
{
schedstat_inc(rq, sched_goidle);
calc_load_account_idle(rq);
return rq->idle;
}

2
kernel/sched/sched.h
View File

@@ -942,8 +942,6 @@ static inline u64 sched_avg_period(void)
return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
}
void calc_load_account_idle(struct rq *this_rq);
#ifdef CONFIG_SCHED_HRTICK
/*

22
kernel/sys.c
View File

@@ -1788,7 +1788,6 @@ SYSCALL_DEFINE1(umask, int, mask)
#ifdef CONFIG_CHECKPOINT_RESTORE
static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
{
struct vm_area_struct *vma;
struct file *exe_file;
struct dentry *dentry;
int err;
@@ -1816,13 +1815,17 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
down_write(&mm->mmap_sem);
/*
* Forbid mm->exe_file change if there are mapped other files.
* Forbid mm->exe_file change if old file still mapped.
*/
err = -EBUSY;
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (vma->vm_file && !path_equal(&vma->vm_file->f_path,
&exe_file->f_path))
goto exit_unlock;
if (mm->exe_file) {
struct vm_area_struct *vma;
for (vma = mm->mmap; vma; vma = vma->vm_next)
if (vma->vm_file &&
path_equal(&vma->vm_file->f_path,
&mm->exe_file->f_path))
goto exit_unlock;
}
/*
@@ -1835,6 +1838,7 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
goto exit_unlock;
err = 0;
set_mm_exe_file(mm, exe_file);
exit_unlock:
up_write(&mm->mmap_sem);
@@ -2127,9 +2131,6 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
else
return -EINVAL;
break;
case PR_GET_TID_ADDRESS:
error = prctl_get_tid_address(me, (int __user **)arg2);
break;
default:
return -EINVAL;
}
@@ -2147,6 +2148,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
case PR_SET_MM:
error = prctl_set_mm(arg2, arg3, arg4, arg5);
break;
case PR_GET_TID_ADDRESS:
error = prctl_get_tid_address(me, (int __user **)arg2);
break;
case PR_SET_CHILD_SUBREAPER:
me->signal->is_child_subreaper = !!arg2;
error = 0;

8
kernel/time/ntp.c
View File

@@ -409,7 +409,9 @@ int second_overflow(unsigned long secs)
time_state = TIME_DEL;
break;
case TIME_INS:
if (secs % 86400 == 0) {
if (!(time_status & STA_INS))
time_state = TIME_OK;
else if (secs % 86400 == 0) {
leap = -1;
time_state = TIME_OOP;
time_tai++;
@@ -418,7 +420,9 @@ int second_overflow(unsigned long secs)
}
break;
case TIME_DEL:
if ((secs + 1) % 86400 == 0) {
if (!(time_status & STA_DEL))
time_state = TIME_OK;
else if ((secs + 1) % 86400 == 0) {
leap = 1;
time_tai--;
time_state = TIME_WAIT;

9
kernel/time/tick-sched.c
View File

@@ -276,10 +276,10 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
{
unsigned long seq, last_jiffies, next_jiffies, delta_jiffies;
ktime_t last_update, expires, ret = { .tv64 = 0 };
unsigned long rcu_delta_jiffies;
struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
u64 time_delta;
/* Read jiffies and the time when jiffies were updated last */
do {
seq = read_seqbegin(&xtime_lock);
@@ -288,7 +288,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
time_delta = timekeeping_max_deferment();
} while (read_seqretry(&xtime_lock, seq));
if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) ||
if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) ||
arch_needs_cpu(cpu)) {
next_jiffies = last_jiffies + 1;
delta_jiffies = 1;
@@ -296,6 +296,10 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
/* Get the next timer wheel timer */
next_jiffies = get_next_timer_interrupt(last_jiffies);
delta_jiffies = next_jiffies - last_jiffies;
if (rcu_delta_jiffies < delta_jiffies) {
next_jiffies = last_jiffies + rcu_delta_jiffies;
delta_jiffies = rcu_delta_jiffies;
}
}
/*
* Do not stop the tick, if we are only one off
@@ -369,6 +373,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
*/
if (!ts->tick_stopped) {
select_nohz_load_balancer(1);
calc_load_enter_idle();
ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
ts->tick_stopped = 1;

63
kernel/time/timekeeping.c
View File

@@ -70,6 +70,12 @@ struct timekeeper {
/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
struct timespec raw_time;
/* Offset clock monotonic -> clock realtime */
ktime_t offs_real;
/* Offset clock monotonic -> clock boottime */
ktime_t offs_boot;
/* Seqlock for all timekeeper values */
seqlock_t lock;
};
@@ -172,6 +178,14 @@ static inline s64 timekeeping_get_ns_raw(void)
return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
}
static void update_rt_offset(void)
{
struct timespec tmp, *wtm = &timekeeper.wall_to_monotonic;
set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
timekeeper.offs_real = timespec_to_ktime(tmp);
}
/* must hold write on timekeeper.lock */
static void timekeeping_update(bool clearntp)
{
@@ -179,6 +193,7 @@ static void timekeeping_update(bool clearntp)
timekeeper.ntp_error = 0;
ntp_clear();
}
update_rt_offset();
update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic,
timekeeper.clock, timekeeper.mult);
}
@@ -604,6 +619,7 @@ void __init timekeeping_init(void)
}
set_normalized_timespec(&timekeeper.wall_to_monotonic,
-boot.tv_sec, -boot.tv_nsec);
update_rt_offset();
timekeeper.total_sleep_time.tv_sec = 0;
timekeeper.total_sleep_time.tv_nsec = 0;
write_sequnlock_irqrestore(&timekeeper.lock, flags);
@@ -612,6 +628,12 @@ void __init timekeeping_init(void)
/* time in seconds when suspend began */
static struct timespec timekeeping_suspend_time;
static void update_sleep_time(struct timespec t)
{
timekeeper.total_sleep_time = t;
timekeeper.offs_boot = timespec_to_ktime(t);
}
/**
* __timekeeping_inject_sleeptime - Internal function to add sleep interval
* @delta: pointer to a timespec delta value
@@ -630,8 +652,7 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta)
timekeeper.xtime = timespec_add(timekeeper.xtime, *delta);
timekeeper.wall_to_monotonic =
timespec_sub(timekeeper.wall_to_monotonic, *delta);
timekeeper.total_sleep_time = timespec_add(
timekeeper.total_sleep_time, *delta);
update_sleep_time(timespec_add(timekeeper.total_sleep_time, *delta));
}
@@ -963,6 +984,8 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
leap = second_overflow(timekeeper.xtime.tv_sec);
timekeeper.xtime.tv_sec += leap;
timekeeper.wall_to_monotonic.tv_sec -= leap;
if (leap)
clock_was_set_delayed();
}
/* Accumulate raw time */
@@ -1079,6 +1102,8 @@ static void update_wall_time(void)
leap = second_overflow(timekeeper.xtime.tv_sec);
timekeeper.xtime.tv_sec += leap;
timekeeper.wall_to_monotonic.tv_sec -= leap;
if (leap)
clock_was_set_delayed();
}
timekeeping_update(false);
@@ -1246,6 +1271,40 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
} while (read_seqretry(&timekeeper.lock, seq));
}
#ifdef CONFIG_HIGH_RES_TIMERS
/**
* ktime_get_update_offsets - hrtimer helper
* @offs_real: pointer to storage for monotonic -> realtime offset
* @offs_boot: pointer to storage for monotonic -> boottime offset
*
* Returns current monotonic time and updates the offsets
* Called from hrtimer_interupt() or retrigger_next_event()
*/
ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
{
ktime_t now;
unsigned int seq;
u64 secs, nsecs;
do {
seq = read_seqbegin(&timekeeper.lock);
secs = timekeeper.xtime.tv_sec;
nsecs = timekeeper.xtime.tv_nsec;
nsecs += timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
*offs_real = timekeeper.offs_real;
*offs_boot = timekeeper.offs_boot;
} while (read_seqretry(&timekeeper.lock, seq));
now = ktime_add_ns(ktime_set(secs, 0), nsecs);
now = ktime_sub(now, *offs_real);
return now;
}
#endif
/**
* ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
*/

6
kernel/trace/ring_buffer.c
View File

@@ -1075,6 +1075,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu)
rb_init_page(bpage->page);
INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
INIT_LIST_HEAD(&cpu_buffer->new_pages);
ret = rb_allocate_pages(cpu_buffer, nr_pages);
if (ret < 0)
@@ -1346,10 +1347,9 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned int nr_pages)
* If something was added to this page, it was full
* since it is not the tail page. So we deduct the
* bytes consumed in ring buffer from here.
* No need to update overruns, since this page is
* deleted from ring buffer and its entries are
* already accounted for.
* Increment overrun to account for the lost events.
*/
local_add(page_entries, &cpu_buffer->overrun);
local_sub(BUF_PAGE_SIZE, &cpu_buffer->entries_bytes);
}

8
kernel/trace/trace.c
View File

@@ -371,7 +371,7 @@ EXPORT_SYMBOL_GPL(tracing_on);
void tracing_off(void)
{
if (global_trace.buffer)
ring_buffer_record_on(global_trace.buffer);
ring_buffer_record_off(global_trace.buffer);
/*
* This flag is only looked at when buffers haven't been
* allocated yet. We don't really care about the race
@@ -3609,6 +3609,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
.pages = pages_def,
.partial = partial_def,
.nr_pages = 0, /* This gets updated below. */
.nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &tracing_pipe_buf_ops,
.spd_release = tracing_spd_release_pipe,
@@ -3680,7 +3681,7 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
ret = splice_to_pipe(pipe, &spd);
out:
splice_shrink_spd(pipe, &spd);
splice_shrink_spd(&spd);
return ret;
out_err:
@@ -4231,6 +4232,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages_def,
.partial = partial_def,
.nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &buffer_pipe_buf_ops,
.spd_release = buffer_spd_release,
@@ -4318,7 +4320,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
}
ret = splice_to_pipe(pipe, &spd);
splice_shrink_spd(pipe, &spd);
splice_shrink_spd(&spd);
out:
return ret;
}

19
kernel/watchdog.c
View File

@@ -372,6 +372,13 @@ static int watchdog(void *unused)
#ifdef CONFIG_HARDLOCKUP_DETECTOR
/*
* People like the simple clean cpu node info on boot.
* Reduce the watchdog noise by only printing messages
* that are different from what cpu0 displayed.
*/
static unsigned long cpu0_err;
static int watchdog_nmi_enable(int cpu)
{
struct perf_event_attr *wd_attr;
@@ -390,11 +397,21 @@ static int watchdog_nmi_enable(int cpu)
/* Try to register using hardware perf events */
event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
/* save cpu0 error for future comparision */
if (cpu == 0 && IS_ERR(event))
cpu0_err = PTR_ERR(event);
if (!IS_ERR(event)) {
pr_info("enabled, takes one hw-pmu counter.\n");
/* only print for cpu0 or different than cpu0 */
if (cpu == 0 || cpu0_err)
pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
goto out_save;
}
/* skip displaying the same error again */
if (cpu > 0 && (PTR_ERR(event) == cpu0_err))
return PTR_ERR(event);
/* vary the KERN level based on the returned errno */
if (PTR_ERR(event) == -EOPNOTSUPP)