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-rw-r--r--kernel/fork.c16
-rw-r--r--kernel/hrtimer.c4
-rw-r--r--kernel/posix-cpu-timers.c70
-rw-r--r--kernel/sched_stats.h33
-rw-r--r--kernel/time/tick-sched.c2
-rw-r--r--kernel/workqueue.c20
6 files changed, 36 insertions, 109 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index bf0cef8bbdf..242a706e772 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -817,17 +817,17 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
{
struct signal_struct *sig;
- int ret;
if (clone_flags & CLONE_THREAD) {
- ret = thread_group_cputime_clone_thread(current);
- if (likely(!ret)) {
- atomic_inc(&current->signal->count);
- atomic_inc(&current->signal->live);
- }
- return ret;
+ atomic_inc(&current->signal->count);
+ atomic_inc(&current->signal->live);
+ return 0;
}
sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
+
+ if (sig)
+ posix_cpu_timers_init_group(sig);
+
tsk->signal = sig;
if (!sig)
return -ENOMEM;
@@ -864,8 +864,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
task_unlock(current->group_leader);
- posix_cpu_timers_init_group(sig);
-
acct_init_pacct(&sig->pacct);
tty_audit_fork(sig);
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 2dc30c59c5f..f33afb0407b 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -614,7 +614,9 @@ void clock_was_set(void)
*/
void hres_timers_resume(void)
{
- /* Retrigger the CPU local events: */
+ WARN_ONCE(!irqs_disabled(),
+ KERN_INFO "hres_timers_resume() called with IRQs enabled!");
+
retrigger_next_event(NULL);
}
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 157de3a4783..fa07da94d7b 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -10,76 +10,6 @@
#include <linux/kernel_stat.h>
/*
- * Allocate the thread_group_cputime structure appropriately and fill in the
- * current values of the fields. Called from copy_signal() via
- * thread_group_cputime_clone_thread() when adding a second or subsequent
- * thread to a thread group. Assumes interrupts are enabled when called.
- */
-int thread_group_cputime_alloc(struct task_struct *tsk)
-{
- struct signal_struct *sig = tsk->signal;
- struct task_cputime *cputime;
-
- /*
- * If we have multiple threads and we don't already have a
- * per-CPU task_cputime struct (checked in the caller), allocate
- * one and fill it in with the times accumulated so far. We may
- * race with another thread so recheck after we pick up the sighand
- * lock.
- */
- cputime = alloc_percpu(struct task_cputime);
- if (cputime == NULL)
- return -ENOMEM;
- spin_lock_irq(&tsk->sighand->siglock);
- if (sig->cputime.totals) {
- spin_unlock_irq(&tsk->sighand->siglock);
- free_percpu(cputime);
- return 0;
- }
- sig->cputime.totals = cputime;
- cputime = per_cpu_ptr(sig->cputime.totals, smp_processor_id());
- cputime->utime = tsk->utime;
- cputime->stime = tsk->stime;
- cputime->sum_exec_runtime = tsk->se.sum_exec_runtime;
- spin_unlock_irq(&tsk->sighand->siglock);
- return 0;
-}
-
-/**
- * thread_group_cputime - Sum the thread group time fields across all CPUs.
- *
- * @tsk: The task we use to identify the thread group.
- * @times: task_cputime structure in which we return the summed fields.
- *
- * Walk the list of CPUs to sum the per-CPU time fields in the thread group
- * time structure.
- */
-void thread_group_cputime(
- struct task_struct *tsk,
- struct task_cputime *times)
-{
- struct task_cputime *totals, *tot;
- int i;
-
- totals = tsk->signal->cputime.totals;
- if (!totals) {
- times->utime = tsk->utime;
- times->stime = tsk->stime;
- times->sum_exec_runtime = tsk->se.sum_exec_runtime;
- return;
- }
-
- times->stime = times->utime = cputime_zero;
- times->sum_exec_runtime = 0;
- for_each_possible_cpu(i) {
- tot = per_cpu_ptr(totals, i);
- times->utime = cputime_add(times->utime, tot->utime);
- times->stime = cputime_add(times->stime, tot->stime);
- times->sum_exec_runtime += tot->sum_exec_runtime;
- }
-}
-
-/*
* Called after updating RLIMIT_CPU to set timer expiration if necessary.
*/
void update_rlimit_cpu(unsigned long rlim_new)
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index f2773b5d122..8ab0cef8eca 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -296,6 +296,7 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next)
static inline void account_group_user_time(struct task_struct *tsk,
cputime_t cputime)
{
+ struct task_cputime *times;
struct signal_struct *sig;
/* tsk == current, ensure it is safe to use ->signal */
@@ -303,13 +304,11 @@ static inline void account_group_user_time(struct task_struct *tsk,
return;
sig = tsk->signal;
- if (sig->cputime.totals) {
- struct task_cputime *times;
+ times = &sig->cputime.totals;
- times = per_cpu_ptr(sig->cputime.totals, get_cpu());
- times->utime = cputime_add(times->utime, cputime);
- put_cpu_no_resched();
- }
+ spin_lock(&times->lock);
+ times->utime = cputime_add(times->utime, cputime);
+ spin_unlock(&times->lock);
}
/**
@@ -325,6 +324,7 @@ static inline void account_group_user_time(struct task_struct *tsk,
static inline void account_group_system_time(struct task_struct *tsk,
cputime_t cputime)
{
+ struct task_cputime *times;
struct signal_struct *sig;
/* tsk == current, ensure it is safe to use ->signal */
@@ -332,13 +332,11 @@ static inline void account_group_system_time(struct task_struct *tsk,
return;
sig = tsk->signal;
- if (sig->cputime.totals) {
- struct task_cputime *times;
+ times = &sig->cputime.totals;
- times = per_cpu_ptr(sig->cputime.totals, get_cpu());
- times->stime = cputime_add(times->stime, cputime);
- put_cpu_no_resched();
- }
+ spin_lock(&times->lock);
+ times->stime = cputime_add(times->stime, cputime);
+ spin_unlock(&times->lock);
}
/**
@@ -354,6 +352,7 @@ static inline void account_group_system_time(struct task_struct *tsk,
static inline void account_group_exec_runtime(struct task_struct *tsk,
unsigned long long ns)
{
+ struct task_cputime *times;
struct signal_struct *sig;
sig = tsk->signal;
@@ -362,11 +361,9 @@ static inline void account_group_exec_runtime(struct task_struct *tsk,
if (unlikely(!sig))
return;
- if (sig->cputime.totals) {
- struct task_cputime *times;
+ times = &sig->cputime.totals;
- times = per_cpu_ptr(sig->cputime.totals, get_cpu());
- times->sum_exec_runtime += ns;
- put_cpu_no_resched();
- }
+ spin_lock(&times->lock);
+ times->sum_exec_runtime += ns;
+ spin_unlock(&times->lock);
}
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 1b6c05bd0d0..d3f1ef4d5cb 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -134,7 +134,7 @@ __setup("nohz=", setup_tick_nohz);
* value. We do this unconditionally on any cpu, as we don't know whether the
* cpu, which has the update task assigned is in a long sleep.
*/
-void tick_nohz_update_jiffies(void)
+static void tick_nohz_update_jiffies(void)
{
int cpu = smp_processor_id();
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 2f445833ae3..1f0c509b40d 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -971,6 +971,8 @@ undo:
}
#ifdef CONFIG_SMP
+static struct workqueue_struct *work_on_cpu_wq __read_mostly;
+
struct work_for_cpu {
struct work_struct work;
long (*fn)(void *);
@@ -991,8 +993,8 @@ static void do_work_for_cpu(struct work_struct *w)
* @fn: the function to run
* @arg: the function arg
*
- * This will return -EINVAL in the cpu is not online, or the return value
- * of @fn otherwise.
+ * This will return the value @fn returns.
+ * It is up to the caller to ensure that the cpu doesn't go offline.
*/
long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
{
@@ -1001,14 +1003,8 @@ long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
INIT_WORK(&wfc.work, do_work_for_cpu);
wfc.fn = fn;
wfc.arg = arg;
- get_online_cpus();
- if (unlikely(!cpu_online(cpu)))
- wfc.ret = -EINVAL;
- else {
- schedule_work_on(cpu, &wfc.work);
- flush_work(&wfc.work);
- }
- put_online_cpus();
+ queue_work_on(cpu, work_on_cpu_wq, &wfc.work);
+ flush_work(&wfc.work);
return wfc.ret;
}
@@ -1025,4 +1021,8 @@ void __init init_workqueues(void)
hotcpu_notifier(workqueue_cpu_callback, 0);
keventd_wq = create_workqueue("events");
BUG_ON(!keventd_wq);
+#ifdef CONFIG_SMP
+ work_on_cpu_wq = create_workqueue("work_on_cpu");
+ BUG_ON(!work_on_cpu_wq);
+#endif
}