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Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  timers: fix TIMER_ABSTIME for process wide cpu timers
  timers: split process wide cpu clocks/timers, fix
  x86: clean up hpet timer reinit
  timers: split process wide cpu clocks/timers, remove spurious warning
  timers: split process wide cpu clocks/timers
  signal: re-add dead task accumulation stats.
  x86: fix hpet timer reinit for x86_64
  sched: fix nohz load balancer on cpu offline
This commit is contained in:
Linus Torvalds 2009-02-11 08:24:32 -08:00
parent 9ce04f9238 4da94d49b2
commit 94dba89533
10 changed files with 209 additions and 75 deletions
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12
arch/x86/kernel/hpet.c
View File

@ -897,13 +897,21 @@ static unsigned long hpet_rtc_flags;
static int hpet_prev_update_sec;
static struct rtc_time hpet_alarm_time;
static unsigned long hpet_pie_count;
static unsigned long hpet_t1_cmp;
static u32 hpet_t1_cmp;
static unsigned long hpet_default_delta;
static unsigned long hpet_pie_delta;
static unsigned long hpet_pie_limit;
static rtc_irq_handler irq_handler;
/*
* Check that the hpet counter c1 is ahead of the c2
*/
static inline int hpet_cnt_ahead(u32 c1, u32 c2)
{
return (s32)(c2 - c1) < 0;
}
/*
* Registers a IRQ handler.
*/
@ -1075,7 +1083,7 @@ static void hpet_rtc_timer_reinit(void)
hpet_t1_cmp += delta;
hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
lost_ints++;
} while ((long)(hpet_readl(HPET_COUNTER) - hpet_t1_cmp) > 0);
} while (!hpet_cnt_ahead(hpet_t1_cmp, hpet_readl(HPET_COUNTER)));
if (lost_ints) {
if (hpet_rtc_flags & RTC_PIE)

11
include/linux/init_task.h
View File

@ -48,12 +48,11 @@ extern struct fs_struct init_fs;
.posix_timers = LIST_HEAD_INIT(sig.posix_timers), \
.cpu_timers = INIT_CPU_TIMERS(sig.cpu_timers), \
.rlim = INIT_RLIMITS, \
.cputime = { .totals = { \
.utime = cputime_zero, \
.stime = cputime_zero, \
.sum_exec_runtime = 0, \
.lock = __SPIN_LOCK_UNLOCKED(sig.cputime.totals.lock), \
}, }, \
.cputimer = { \
.cputime = INIT_CPUTIME, \
.running = 0, \
.lock = __SPIN_LOCK_UNLOCKED(sig.cputimer.lock), \
}, \
}
extern struct nsproxy init_nsproxy;

64
include/linux/sched.h
View File

@ -443,7 +443,6 @@ struct pacct_struct {
* @utime: time spent in user mode, in &cputime_t units
* @stime: time spent in kernel mode, in &cputime_t units
* @sum_exec_runtime: total time spent on the CPU, in nanoseconds
* @lock: lock for fields in this struct
*
* This structure groups together three kinds of CPU time that are
* tracked for threads and thread groups. Most things considering
@ -454,23 +453,33 @@ struct task_cputime {
cputime_t utime;
cputime_t stime;
unsigned long long sum_exec_runtime;
spinlock_t lock;
};
/* Alternate field names when used to cache expirations. */
#define prof_exp stime
#define virt_exp utime
#define sched_exp sum_exec_runtime
#define INIT_CPUTIME \
(struct task_cputime) { \
.utime = cputime_zero, \
.stime = cputime_zero, \
.sum_exec_runtime = 0, \
}
/**
* struct thread_group_cputime - thread group interval timer counts
* @totals: thread group interval timers; substructure for
* uniprocessor kernel, per-cpu for SMP kernel.
* struct thread_group_cputimer - thread group interval timer counts
* @cputime: thread group interval timers.
* @running: non-zero when there are timers running and
* @cputime receives updates.
* @lock: lock for fields in this struct.
*
* This structure contains the version of task_cputime, above, that is
* used for thread group CPU clock calculations.
* used for thread group CPU timer calculations.
*/
struct thread_group_cputime {
struct task_cputime totals;
struct thread_group_cputimer {
struct task_cputime cputime;
int running;
spinlock_t lock;
};
/*
@ -519,10 +528,10 @@ struct signal_struct {
cputime_t it_prof_incr, it_virt_incr;
/*
* Thread group totals for process CPU clocks.
* See thread_group_cputime(), et al, for details.
* Thread group totals for process CPU timers.
* See thread_group_cputimer(), et al, for details.
*/
struct thread_group_cputime cputime;
struct thread_group_cputimer cputimer;
/* Earliest-expiration cache. */
struct task_cputime cputime_expires;
@ -559,7 +568,7 @@ struct signal_struct {
* Live threads maintain their own counters and add to these
* in __exit_signal, except for the group leader.
*/
cputime_t cutime, cstime;
cputime_t utime, stime, cutime, cstime;
cputime_t gtime;
cputime_t cgtime;
unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
@ -567,6 +576,14 @@ struct signal_struct {
unsigned long inblock, oublock, cinblock, coublock;
struct task_io_accounting ioac;
/*
* Cumulative ns of schedule CPU time fo dead threads in the
* group, not including a zombie group leader, (This only differs
* from jiffies_to_ns(utime + stime) if sched_clock uses something
* other than jiffies.)
*/
unsigned long long sum_sched_runtime;
/*
* We don't bother to synchronize most readers of this at all,
* because there is no reader checking a limit that actually needs
@ -2183,27 +2200,14 @@ static inline int spin_needbreak(spinlock_t *lock)
/*
* Thread group CPU time accounting.
*/
static inline
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
{
struct task_cputime *totals = &tsk->signal->cputime.totals;
unsigned long flags;
spin_lock_irqsave(&totals->lock, flags);
*times = *totals;
spin_unlock_irqrestore(&totals->lock, flags);
}
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
static inline void thread_group_cputime_init(struct signal_struct *sig)
{
sig->cputime.totals = (struct task_cputime){
.utime = cputime_zero,
.stime = cputime_zero,
.sum_exec_runtime = 0,
};
spin_lock_init(&sig->cputime.totals.lock);
sig->cputimer.cputime = INIT_CPUTIME;
spin_lock_init(&sig->cputimer.lock);
sig->cputimer.running = 0;
}
static inline void thread_group_cputime_free(struct signal_struct *sig)

3
kernel/exit.c
View File

@ -118,6 +118,8 @@ static void __exit_signal(struct task_struct *tsk)
* We won't ever get here for the group leader, since it
* will have been the last reference on the signal_struct.
*/
sig->utime = cputime_add(sig->utime, task_utime(tsk));
sig->stime = cputime_add(sig->stime, task_stime(tsk));
sig->gtime = cputime_add(sig->gtime, task_gtime(tsk));
sig->min_flt += tsk->min_flt;
sig->maj_flt += tsk->maj_flt;
@ -126,6 +128,7 @@ static void __exit_signal(struct task_struct *tsk)
sig->inblock += task_io_get_inblock(tsk);
sig->oublock += task_io_get_oublock(tsk);
task_io_accounting_add(&sig->ioac, &tsk->ioac);
sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
sig = NULL; /* Marker for below. */
}

3
kernel/fork.c
View File

@ -851,13 +851,14 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
sig->tty_old_pgrp = NULL;
sig->tty = NULL;
sig->cutime = sig->cstime = cputime_zero;
sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
sig->gtime = cputime_zero;
sig->cgtime = cputime_zero;
sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
task_io_accounting_init(&sig->ioac);
sig->sum_sched_runtime = 0;
taskstats_tgid_init(sig);
task_lock(current->group_leader);

4
kernel/itimer.c
View File

@ -62,7 +62,7 @@ int do_getitimer(int which, struct itimerval *value)
struct task_cputime cputime;
cputime_t utime;
thread_group_cputime(tsk, &cputime);
thread_group_cputimer(tsk, &cputime);
utime = cputime.utime;
if (cputime_le(cval, utime)) { /* about to fire */
cval = jiffies_to_cputime(1);
@ -82,7 +82,7 @@ int do_getitimer(int which, struct itimerval *value)
struct task_cputime times;
cputime_t ptime;
thread_group_cputime(tsk, &times);
thread_group_cputimer(tsk, &times);
ptime = cputime_add(times.utime, times.stime);
if (cputime_le(cval, ptime)) { /* about to fire */
cval = jiffies_to_cputime(1);

117
kernel/posix-cpu-timers.c
View File

@ -230,6 +230,71 @@ static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
return 0;
}
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
{
struct sighand_struct *sighand;
struct signal_struct *sig;
struct task_struct *t;
*times = INIT_CPUTIME;
rcu_read_lock();
sighand = rcu_dereference(tsk->sighand);
if (!sighand)
goto out;
sig = tsk->signal;
t = tsk;
do {
times->utime = cputime_add(times->utime, t->utime);
times->stime = cputime_add(times->stime, t->stime);
times->sum_exec_runtime += t->se.sum_exec_runtime;
t = next_thread(t);
} while (t != tsk);
times->utime = cputime_add(times->utime, sig->utime);
times->stime = cputime_add(times->stime, sig->stime);
times->sum_exec_runtime += sig->sum_sched_runtime;
out:
rcu_read_unlock();
}
static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
{
if (cputime_gt(b->utime, a->utime))
a->utime = b->utime;
if (cputime_gt(b->stime, a->stime))
a->stime = b->stime;
if (b->sum_exec_runtime > a->sum_exec_runtime)
a->sum_exec_runtime = b->sum_exec_runtime;
}
void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
struct task_cputime sum;
unsigned long flags;
spin_lock_irqsave(&cputimer->lock, flags);
if (!cputimer->running) {
cputimer->running = 1;
/*
* The POSIX timer interface allows for absolute time expiry
* values through the TIMER_ABSTIME flag, therefore we have
* to synchronize the timer to the clock every time we start
* it.
*/
thread_group_cputime(tsk, &sum);
update_gt_cputime(&cputimer->cputime, &sum);
}
*times = cputimer->cputime;
spin_unlock_irqrestore(&cputimer->lock, flags);
}
/*
* Sample a process (thread group) clock for the given group_leader task.
* Must be called with tasklist_lock held for reading.
@ -457,7 +522,7 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk)
{
struct task_cputime cputime;
thread_group_cputime(tsk, &cputime);
thread_group_cputimer(tsk, &cputime);
cleanup_timers(tsk->signal->cpu_timers,
cputime.utime, cputime.stime, cputime.sum_exec_runtime);
}
@ -964,6 +1029,19 @@ static void check_thread_timers(struct task_struct *tsk,
}
}
static void stop_process_timers(struct task_struct *tsk)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
unsigned long flags;
if (!cputimer->running)
return;
spin_lock_irqsave(&cputimer->lock, flags);
cputimer->running = 0;
spin_unlock_irqrestore(&cputimer->lock, flags);
}
/*
* Check for any per-thread CPU timers that have fired and move them
* off the tsk->*_timers list onto the firing list. Per-thread timers
@ -987,13 +1065,15 @@ static void check_process_timers(struct task_struct *tsk,
sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
list_empty(&timers[CPUCLOCK_VIRT]) &&
cputime_eq(sig->it_virt_expires, cputime_zero) &&
list_empty(&timers[CPUCLOCK_SCHED]))
list_empty(&timers[CPUCLOCK_SCHED])) {
stop_process_timers(tsk);
return;
}
/*
* Collect the current process totals.
*/
thread_group_cputime(tsk, &cputime);
thread_group_cputimer(tsk, &cputime);
utime = cputime.utime;
ptime = cputime_add(utime, cputime.stime);
sum_sched_runtime = cputime.sum_exec_runtime;
@ -1259,7 +1339,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
if (!task_cputime_zero(&sig->cputime_expires)) {
struct task_cputime group_sample;
thread_group_cputime(tsk, &group_sample);
thread_group_cputimer(tsk, &group_sample);
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
}
@ -1328,6 +1408,33 @@ void run_posix_cpu_timers(struct task_struct *tsk)
}
}
/*
* Sample a process (thread group) timer for the given group_leader task.
* Must be called with tasklist_lock held for reading.
*/
static int cpu_timer_sample_group(const clockid_t which_clock,
struct task_struct *p,
union cpu_time_count *cpu)
{
struct task_cputime cputime;
thread_group_cputimer(p, &cputime);
switch (CPUCLOCK_WHICH(which_clock)) {
default:
return -EINVAL;
case CPUCLOCK_PROF:
cpu->cpu = cputime_add(cputime.utime, cputime.stime);
break;
case CPUCLOCK_VIRT:
cpu->cpu = cputime.utime;
break;
case CPUCLOCK_SCHED:
cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
break;
}
return 0;
}
/*
* Set one of the process-wide special case CPU timers.
* The tsk->sighand->siglock must be held by the caller.
@ -1341,7 +1448,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
struct list_head *head;
BUG_ON(clock_idx == CPUCLOCK_SCHED);
cpu_clock_sample_group(clock_idx, tsk, &now);
cpu_timer_sample_group(clock_idx, tsk, &now);
if (oldval) {
if (!cputime_eq(*oldval, cputime_zero)) {

17
kernel/sched.c
View File

@ -3890,19 +3890,24 @@ int select_nohz_load_balancer(int stop_tick)
int cpu = smp_processor_id();
if (stop_tick) {
cpumask_set_cpu(cpu, nohz.cpu_mask);
cpu_rq(cpu)->in_nohz_recently = 1;
/*
* If we are going offline and still the leader, give up!
*/
if (!cpu_active(cpu) &&
atomic_read(&nohz.load_balancer) == cpu) {
if (!cpu_active(cpu)) {
if (atomic_read(&nohz.load_balancer) != cpu)
return 0;
/*
* If we are going offline and still the leader,
* give up!
*/
if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
BUG();
return 0;
}
cpumask_set_cpu(cpu, nohz.cpu_mask);
/* time for ilb owner also to sleep */
if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
if (atomic_read(&nohz.load_balancer) == cpu)

45
kernel/sched_stats.h
View File

@ -296,19 +296,21 @@ 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;
struct thread_group_cputimer *cputimer;
/* tsk == current, ensure it is safe to use ->signal */
if (unlikely(tsk->exit_state))
return;
sig = tsk->signal;
times = &sig->cputime.totals;
cputimer = &tsk->signal->cputimer;
spin_lock(&times->lock);
times->utime = cputime_add(times->utime, cputime);
spin_unlock(&times->lock);
if (!cputimer->running)
return;
spin_lock(&cputimer->lock);
cputimer->cputime.utime =
cputime_add(cputimer->cputime.utime, cputime);
spin_unlock(&cputimer->lock);
}
/**
@ -324,19 +326,21 @@ 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;
struct thread_group_cputimer *cputimer;
/* tsk == current, ensure it is safe to use ->signal */
if (unlikely(tsk->exit_state))
return;
sig = tsk->signal;
times = &sig->cputime.totals;
cputimer = &tsk->signal->cputimer;
spin_lock(&times->lock);
times->stime = cputime_add(times->stime, cputime);
spin_unlock(&times->lock);
if (!cputimer->running)
return;
spin_lock(&cputimer->lock);
cputimer->cputime.stime =
cputime_add(cputimer->cputime.stime, cputime);
spin_unlock(&cputimer->lock);
}
/**
@ -352,7 +356,7 @@ 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 thread_group_cputimer *cputimer;
struct signal_struct *sig;
sig = tsk->signal;
@ -361,9 +365,12 @@ static inline void account_group_exec_runtime(struct task_struct *tsk,
if (unlikely(!sig))
return;
times = &sig->cputime.totals;
cputimer = &sig->cputimer;
spin_lock(&times->lock);
times->sum_exec_runtime += ns;
spin_unlock(&times->lock);
if (!cputimer->running)
return;
spin_lock(&cputimer->lock);
cputimer->cputime.sum_exec_runtime += ns;
spin_unlock(&cputimer->lock);
}

8
kernel/signal.c
View File

@ -1367,7 +1367,6 @@ int do_notify_parent(struct task_struct *tsk, int sig)
struct siginfo info;
unsigned long flags;
struct sighand_struct *psig;
struct task_cputime cputime;
int ret = sig;
BUG_ON(sig == -1);
@ -1397,9 +1396,10 @@ int do_notify_parent(struct task_struct *tsk, int sig)
info.si_uid = __task_cred(tsk)->uid;
rcu_read_unlock();
thread_group_cputime(tsk, &cputime);
info.si_utime = cputime_to_jiffies(cputime.utime);
info.si_stime = cputime_to_jiffies(cputime.stime);
info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime,
tsk->signal->utime));
info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime,
tsk->signal->stime));
info.si_status = tsk->exit_code & 0x7f;
if (tsk->exit_code & 0x80)