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

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (35 commits)
  sched, cputime: Introduce thread_group_times()
  sched, cputime: Cleanups related to task_times()
  Revert "sched, x86: Optimize branch hint in __switch_to()"
  sched: Fix isolcpus boot option
  sched: Revert 498657a478
  sched, time: Define nsecs_to_jiffies()
  sched: Remove task_{u,s,g}time()
  sched: Introduce task_times() to replace task_{u,s}time() pair
  sched: Limit the number of scheduler debug messages
  sched.c: Call debug_show_all_locks() when dumping all tasks
  sched, x86: Optimize branch hint in __switch_to()
  sched: Optimize branch hint in context_switch()
  sched: Optimize branch hint in pick_next_task_fair()
  sched_feat_write(): Update ppos instead of file->f_pos
  sched: Sched_rt_periodic_timer vs cpu hotplug
  sched, kvm: Fix race condition involving sched_in_preempt_notifers
  sched: More generic WAKE_AFFINE vs select_idle_sibling()
  sched: Cleanup select_task_rq_fair()
  sched: Fix granularity of task_u/stime()
  sched: Fix/add missing update_rq_clock() calls
  ...
This commit is contained in:
Linus Torvalds 2009-12-05 15:30:49 -08:00
parent c3fa27d136 0cf55e1ec0
commit 897e81bea1
19 changed files with 399 additions and 203 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
Documentation/feature-removal-schedule.txt
View File

@ -6,6 +6,21 @@ be removed from this file.
---------------------------
What: USER_SCHED
When: 2.6.34
Why: USER_SCHED was implemented as a proof of concept for group scheduling.
The effect of USER_SCHED can already be achieved from userspace with
the help of libcgroup. The removal of USER_SCHED will also simplify
the scheduler code with the removal of one major ifdef. There are also
issues USER_SCHED has with USER_NS. A decision was taken not to fix
those and instead remove USER_SCHED. Also new group scheduling
features will not be implemented for USER_SCHED.
Who: Dhaval Giani <dhaval@linux.vnet.ibm.com>
---------------------------
What: PRISM54
When: 2.6.34

3
Documentation/filesystems/proc.txt
View File

@ -1072,7 +1072,8 @@ second). The meanings of the columns are as follows, from left to right:
- irq: servicing interrupts
- softirq: servicing softirqs
- steal: involuntary wait
- guest: running a guest
- guest: running a normal guest
- guest_nice: running a niced guest
The "intr" line gives counts of interrupts serviced since boot time, for each
of the possible system interrupts. The first column is the total of all

2
Documentation/kernel-parameters.txt
View File

@ -2186,6 +2186,8 @@ and is between 256 and 4096 characters. It is defined in the file
sbni= [NET] Granch SBNI12 leased line adapter
sched_debug [KNL] Enables verbose scheduler debug messages.
sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
Format: <io>[,<timeout>[,<isapnp>]]

23
fs/proc/array.c
View File

@ -410,6 +410,16 @@ static void task_show_stack_usage(struct seq_file *m, struct task_struct *task)
}
#endif /* CONFIG_MMU */
static void task_cpus_allowed(struct seq_file *m, struct task_struct *task)
{
seq_printf(m, "Cpus_allowed:\t");
seq_cpumask(m, &task->cpus_allowed);
seq_printf(m, "\n");
seq_printf(m, "Cpus_allowed_list:\t");
seq_cpumask_list(m, &task->cpus_allowed);
seq_printf(m, "\n");
}
int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
@ -424,6 +434,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
}
task_sig(m, task);
task_cap(m, task);
task_cpus_allowed(m, task);
cpuset_task_status_allowed(m, task);
#if defined(CONFIG_S390)
task_show_regs(m, task);
@ -495,20 +506,17 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
/* add up live thread stats at the group level */
if (whole) {
struct task_cputime cputime;
struct task_struct *t = task;
do {
min_flt += t->min_flt;
maj_flt += t->maj_flt;
gtime = cputime_add(gtime, task_gtime(t));
gtime = cputime_add(gtime, t->gtime);
t = next_thread(t);
} while (t != task);
min_flt += sig->min_flt;
maj_flt += sig->maj_flt;
thread_group_cputime(task, &cputime);
utime = cputime.utime;
stime = cputime.stime;
thread_group_times(task, &utime, &stime);
gtime = cputime_add(gtime, sig->gtime);
}
@ -524,9 +532,8 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
if (!whole) {
min_flt = task->min_flt;
maj_flt = task->maj_flt;
utime = task_utime(task);
stime = task_stime(task);
gtime = task_gtime(task);
task_times(task, &utime, &stime);
gtime = task->gtime;
}
/* scale priority and nice values from timeslices to -20..20 */

19
fs/proc/stat.c
View File

@ -27,7 +27,7 @@ static int show_stat(struct seq_file *p, void *v)
int i, j;
unsigned long jif;
cputime64_t user, nice, system, idle, iowait, irq, softirq, steal;
cputime64_t guest;
cputime64_t guest, guest_nice;
u64 sum = 0;
u64 sum_softirq = 0;
unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
@ -36,7 +36,7 @@ static int show_stat(struct seq_file *p, void *v)
user = nice = system = idle = iowait =
irq = softirq = steal = cputime64_zero;
guest = cputime64_zero;
guest = guest_nice = cputime64_zero;
getboottime(&boottime);
jif = boottime.tv_sec;
@ -51,6 +51,8 @@ static int show_stat(struct seq_file *p, void *v)
softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq);
steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal);
guest = cputime64_add(guest, kstat_cpu(i).cpustat.guest);
guest_nice = cputime64_add(guest_nice,
kstat_cpu(i).cpustat.guest_nice);
for_each_irq_nr(j) {
sum += kstat_irqs_cpu(j, i);
}
@ -65,7 +67,8 @@ static int show_stat(struct seq_file *p, void *v)
}
sum += arch_irq_stat();
seq_printf(p, "cpu %llu %llu %llu %llu %llu %llu %llu %llu %llu\n",
seq_printf(p, "cpu %llu %llu %llu %llu %llu %llu %llu %llu %llu "
"%llu\n",
(unsigned long long)cputime64_to_clock_t(user),
(unsigned long long)cputime64_to_clock_t(nice),
(unsigned long long)cputime64_to_clock_t(system),
@ -74,7 +77,8 @@ static int show_stat(struct seq_file *p, void *v)
(unsigned long long)cputime64_to_clock_t(irq),
(unsigned long long)cputime64_to_clock_t(softirq),
(unsigned long long)cputime64_to_clock_t(steal),
(unsigned long long)cputime64_to_clock_t(guest));
(unsigned long long)cputime64_to_clock_t(guest),
(unsigned long long)cputime64_to_clock_t(guest_nice));
for_each_online_cpu(i) {
/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
@ -88,8 +92,10 @@ static int show_stat(struct seq_file *p, void *v)
softirq = kstat_cpu(i).cpustat.softirq;
steal = kstat_cpu(i).cpustat.steal;
guest = kstat_cpu(i).cpustat.guest;
guest_nice = kstat_cpu(i).cpustat.guest_nice;
seq_printf(p,
"cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu\n",
"cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu "
"%llu\n",
i,
(unsigned long long)cputime64_to_clock_t(user),
(unsigned long long)cputime64_to_clock_t(nice),
@ -99,7 +105,8 @@ static int show_stat(struct seq_file *p, void *v)
(unsigned long long)cputime64_to_clock_t(irq),
(unsigned long long)cputime64_to_clock_t(softirq),
(unsigned long long)cputime64_to_clock_t(steal),
(unsigned long long)cputime64_to_clock_t(guest));
(unsigned long long)cputime64_to_clock_t(guest),
(unsigned long long)cputime64_to_clock_t(guest_nice));
}
seq_printf(p, "intr %llu", (unsigned long long)sum);

1
include/linux/jiffies.h
View File

@ -307,6 +307,7 @@ extern clock_t jiffies_to_clock_t(long x);
extern unsigned long clock_t_to_jiffies(unsigned long x);
extern u64 jiffies_64_to_clock_t(u64 x);
extern u64 nsec_to_clock_t(u64 x);
extern unsigned long nsecs_to_jiffies(u64 n);
#define TIMESTAMP_SIZE 30

1
include/linux/kernel_stat.h
View File

@ -25,6 +25,7 @@ struct cpu_usage_stat {
cputime64_t iowait;
cputime64_t steal;
cputime64_t guest;
cputime64_t guest_nice;
};
struct kernel_stat {

5
include/linux/preempt.h
View File

@ -105,6 +105,11 @@ struct preempt_notifier;
* @sched_out: we've just been preempted
* notifier: struct preempt_notifier for the task being preempted
* next: the task that's kicking us out
*
* Please note that sched_in and out are called under different
* contexts. sched_out is called with rq lock held and irq disabled
* while sched_in is called without rq lock and irq enabled. This
* difference is intentional and depended upon by its users.
*/
struct preempt_ops {
void (*sched_in)(struct preempt_notifier *notifier, int cpu);

22
include/linux/sched.h
View File

@ -145,7 +145,6 @@ extern unsigned long this_cpu_load(void);
extern void calc_global_load(void);
extern u64 cpu_nr_migrations(int cpu);
extern unsigned long get_parent_ip(unsigned long addr);
@ -171,8 +170,6 @@ print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
}
#endif
extern unsigned long long time_sync_thresh;
/*
* Task state bitmask. NOTE! These bits are also
* encoded in fs/proc/array.c: get_task_state().
@ -349,7 +346,6 @@ extern signed long schedule_timeout(signed long timeout);
extern signed long schedule_timeout_interruptible(signed long timeout);
extern signed long schedule_timeout_killable(signed long timeout);
extern signed long schedule_timeout_uninterruptible(signed long timeout);
asmlinkage void __schedule(void);
asmlinkage void schedule(void);
extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
@ -628,6 +624,9 @@ struct signal_struct {
cputime_t utime, stime, cutime, cstime;
cputime_t gtime;
cputime_t cgtime;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
cputime_t prev_utime, prev_stime;
#endif
unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
unsigned long inblock, oublock, cinblock, coublock;
@ -1013,9 +1012,13 @@ static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
return to_cpumask(sd->span);
}
extern void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
struct sched_domain_attr *dattr_new);
/* Allocate an array of sched domains, for partition_sched_domains(). */
cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
/* Test a flag in parent sched domain */
static inline int test_sd_parent(struct sched_domain *sd, int flag)
{
@ -1033,7 +1036,7 @@ unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
struct sched_domain_attr;
static inline void
partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
struct sched_domain_attr *dattr_new)
{
}
@ -1331,7 +1334,9 @@ struct task_struct {
cputime_t utime, stime, utimescaled, stimescaled;
cputime_t gtime;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
cputime_t prev_utime, prev_stime;
#endif
unsigned long nvcsw, nivcsw; /* context switch counts */
struct timespec start_time; /* monotonic time */
struct timespec real_start_time; /* boot based time */
@ -1720,9 +1725,8 @@ static inline void put_task_struct(struct task_struct *t)
__put_task_struct(t);
}
extern cputime_t task_utime(struct task_struct *p);
extern cputime_t task_stime(struct task_struct *p);
extern cputime_t task_gtime(struct task_struct *p);
extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
/*
* Per process flags

27
kernel/cpuset.c
View File

@ -537,8 +537,7 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
* element of the partition (one sched domain) to be passed to
* partition_sched_domains().
*/
/* FIXME: see the FIXME in partition_sched_domains() */
static int generate_sched_domains(struct cpumask **domains,
static int generate_sched_domains(cpumask_var_t **domains,
struct sched_domain_attr **attributes)
{
LIST_HEAD(q); /* queue of cpusets to be scanned */
@ -546,7 +545,7 @@ static int generate_sched_domains(struct cpumask **domains,
struct cpuset **csa; /* array of all cpuset ptrs */
int csn; /* how many cpuset ptrs in csa so far */
int i, j, k; /* indices for partition finding loops */
struct cpumask *doms; /* resulting partition; i.e. sched domains */
cpumask_var_t *doms; /* resulting partition; i.e. sched domains */
struct sched_domain_attr *dattr; /* attributes for custom domains */
int ndoms = 0; /* number of sched domains in result */
int nslot; /* next empty doms[] struct cpumask slot */
@ -557,7 +556,8 @@ static int generate_sched_domains(struct cpumask **domains,
/* Special case for the 99% of systems with one, full, sched domain */
if (is_sched_load_balance(&top_cpuset)) {
doms = kmalloc(cpumask_size(), GFP_KERNEL);
ndoms = 1;
doms = alloc_sched_domains(ndoms);
if (!doms)
goto done;
@ -566,9 +566,8 @@ static int generate_sched_domains(struct cpumask **domains,
*dattr = SD_ATTR_INIT;
update_domain_attr_tree(dattr, &top_cpuset);
}
cpumask_copy(doms, top_cpuset.cpus_allowed);
cpumask_copy(doms[0], top_cpuset.cpus_allowed);
ndoms = 1;
goto done;
}
@ -636,7 +635,7 @@ restart:
* Now we know how many domains to create.
* Convert <csn, csa> to <ndoms, doms> and populate cpu masks.
*/
doms = kmalloc(ndoms * cpumask_size(), GFP_KERNEL);
doms = alloc_sched_domains(ndoms);
if (!doms)
goto done;
@ -656,7 +655,7 @@ restart:
continue;
}
dp = doms + nslot;
dp = doms[nslot];
if (nslot == ndoms) {
static int warnings = 10;
@ -718,7 +717,7 @@ done:
static void do_rebuild_sched_domains(struct work_struct *unused)
{
struct sched_domain_attr *attr;
struct cpumask *doms;
cpumask_var_t *doms;
int ndoms;
get_online_cpus();
@ -2052,7 +2051,7 @@ static int cpuset_track_online_cpus(struct notifier_block *unused_nb,
unsigned long phase, void *unused_cpu)
{
struct sched_domain_attr *attr;
struct cpumask *doms;
cpumask_var_t *doms;
int ndoms;
switch (phase) {
@ -2537,15 +2536,9 @@ const struct file_operations proc_cpuset_operations = {
};
#endif /* CONFIG_PROC_PID_CPUSET */
/* Display task cpus_allowed, mems_allowed in /proc/<pid>/status file. */
/* Display task mems_allowed in /proc/<pid>/status file. */
void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task)
{
seq_printf(m, "Cpus_allowed:\t");
seq_cpumask(m, &task->cpus_allowed);
seq_printf(m, "\n");
seq_printf(m, "Cpus_allowed_list:\t");
seq_cpumask_list(m, &task->cpus_allowed);
seq_printf(m, "\n");
seq_printf(m, "Mems_allowed:\t");
seq_nodemask(m, &task->mems_allowed);
seq_printf(m, "\n");

22
kernel/exit.c
View File

@ -111,9 +111,9 @@ 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->utime = cputime_add(sig->utime, tsk->utime);
sig->stime = cputime_add(sig->stime, tsk->stime);
sig->gtime = cputime_add(sig->gtime, tsk->gtime);
sig->min_flt += tsk->min_flt;
sig->maj_flt += tsk->maj_flt;
sig->nvcsw += tsk->nvcsw;
@ -1210,6 +1210,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
struct signal_struct *psig;
struct signal_struct *sig;
unsigned long maxrss;
cputime_t tgutime, tgstime;
/*
* The resource counters for the group leader are in its
@ -1225,20 +1226,23 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
* need to protect the access to parent->signal fields,
* as other threads in the parent group can be right
* here reaping other children at the same time.
*
* We use thread_group_times() to get times for the thread
* group, which consolidates times for all threads in the
* group including the group leader.
*/
thread_group_times(p, &tgutime, &tgstime);
spin_lock_irq(&p->real_parent->sighand->siglock);
psig = p->real_parent->signal;
sig = p->signal;
psig->cutime =
cputime_add(psig->cutime,
cputime_add(p->utime,
cputime_add(sig->utime,
sig->cutime)));
cputime_add(tgutime,
sig->cutime));
psig->cstime =
cputime_add(psig->cstime,
cputime_add(p->stime,
cputime_add(sig->stime,
sig->cstime)));
cputime_add(tgstime,
sig->cstime));
psig->cgtime =
cputime_add(psig->cgtime,
cputime_add(p->gtime,

5
kernel/fork.c
View File

@ -884,6 +884,9 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
sig->gtime = cputime_zero;
sig->cgtime = cputime_zero;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
sig->prev_utime = sig->prev_stime = cputime_zero;
#endif
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;
@ -1066,8 +1069,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->gtime = cputime_zero;
p->utimescaled = cputime_zero;
p->stimescaled = cputime_zero;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
p->prev_utime = cputime_zero;
p->prev_stime = cputime_zero;
#endif
p->default_timer_slack_ns = current->timer_slack_ns;

2
kernel/kgdb.c
View File

@ -870,7 +870,7 @@ static void gdb_cmd_getregs(struct kgdb_state *ks)
/*
* All threads that don't have debuggerinfo should be
* in __schedule() sleeping, since all other CPUs
* in schedule() sleeping, since all other CPUs
* are in kgdb_wait, and thus have debuggerinfo.
*/
if (local_debuggerinfo) {

276
kernel/sched.c
View File

@ -535,14 +535,12 @@ struct rq {
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
#ifdef CONFIG_NO_HZ
unsigned long last_tick_seen;
unsigned char in_nohz_recently;
#endif
/* capture load from *all* tasks on this cpu: */
struct load_weight load;
unsigned long nr_load_updates;
u64 nr_switches;
u64 nr_migrations_in;
struct cfs_rq cfs;
struct rt_rq rt;
@ -591,6 +589,8 @@ struct rq {
u64 rt_avg;
u64 age_stamp;
u64 idle_stamp;
u64 avg_idle;
#endif
/* calc_load related fields */
@ -772,7 +772,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
if (!sched_feat_names[i])
return -EINVAL;
filp->f_pos += cnt;
*ppos += cnt;
return cnt;
}
@ -2017,6 +2017,7 @@ void kthread_bind(struct task_struct *p, unsigned int cpu)
}
spin_lock_irqsave(&rq->lock, flags);
update_rq_clock(rq);
set_task_cpu(p, cpu);
p->cpus_allowed = cpumask_of_cpu(cpu);
p->rt.nr_cpus_allowed = 1;
@ -2078,7 +2079,6 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
#endif
if (old_cpu != new_cpu) {
p->se.nr_migrations++;
new_rq->nr_migrations_in++;
#ifdef CONFIG_SCHEDSTATS
if (task_hot(p, old_rq->clock, NULL))
schedstat_inc(p, se.nr_forced2_migrations);
@ -2115,6 +2115,7 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
* it is sufficient to simply update the task's cpu field.
*/
if (!p->se.on_rq && !task_running(rq, p)) {
update_rq_clock(rq);
set_task_cpu(p, dest_cpu);
return 0;
}
@ -2376,13 +2377,14 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
task_rq_unlock(rq, &flags);
cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
if (cpu != orig_cpu)
set_task_cpu(p, cpu);
rq = task_rq_lock(p, &flags);
if (rq != orig_rq)
if (cpu != orig_cpu) {
local_irq_save(flags);
rq = cpu_rq(cpu);
update_rq_clock(rq);
set_task_cpu(p, cpu);
local_irq_restore(flags);
}
rq = task_rq_lock(p, &flags);
WARN_ON(p->state != TASK_WAKING);
cpu = task_cpu(p);
@ -2440,6 +2442,17 @@ out_running:
#ifdef CONFIG_SMP
if (p->sched_class->task_wake_up)
p->sched_class->task_wake_up(rq, p);
if (unlikely(rq->idle_stamp)) {
u64 delta = rq->clock - rq->idle_stamp;
u64 max = 2*sysctl_sched_migration_cost;
if (delta > max)
rq->avg_idle = max;
else
update_avg(&rq->avg_idle, delta);
rq->idle_stamp = 0;
}
#endif
out:
task_rq_unlock(rq, &flags);
@ -2545,6 +2558,7 @@ static void __sched_fork(struct task_struct *p)
void sched_fork(struct task_struct *p, int clone_flags)
{
int cpu = get_cpu();
unsigned long flags;
__sched_fork(p);
@ -2581,7 +2595,10 @@ void sched_fork(struct task_struct *p, int clone_flags)
#ifdef CONFIG_SMP
cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0);
#endif
local_irq_save(flags);
update_rq_clock(cpu_rq(cpu));
set_task_cpu(p, cpu);
local_irq_restore(flags);
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))
@ -2848,14 +2865,14 @@ context_switch(struct rq *rq, struct task_struct *prev,
*/
arch_start_context_switch(prev);
if (unlikely(!mm)) {
if (likely(!mm)) {
next->active_mm = oldmm;
atomic_inc(&oldmm->mm_count);
enter_lazy_tlb(oldmm, next);
} else
switch_mm(oldmm, mm, next);
if (unlikely(!prev->mm)) {
if (likely(!prev->mm)) {
prev->active_mm = NULL;
rq->prev_mm = oldmm;
}
@ -3017,15 +3034,6 @@ static void calc_load_account_active(struct rq *this_rq)
}
}
/*
* Externally visible per-cpu scheduler statistics:
* cpu_nr_migrations(cpu) - number of migrations into that cpu
*/
u64 cpu_nr_migrations(int cpu)
{
return cpu_rq(cpu)->nr_migrations_in;
}
/*
* Update rq->cpu_load[] statistics. This function is usually called every
* scheduler tick (TICK_NSEC).
@ -4126,7 +4134,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
unsigned long flags;
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
cpumask_setall(cpus);
cpumask_copy(cpus, cpu_online_mask);
/*
* When power savings policy is enabled for the parent domain, idle
@ -4289,7 +4297,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd)
int all_pinned = 0;
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
cpumask_setall(cpus);
cpumask_copy(cpus, cpu_online_mask);
/*
* When power savings policy is enabled for the parent domain, idle
@ -4429,6 +4437,11 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
int pulled_task = 0;
unsigned long next_balance = jiffies + HZ;
this_rq->idle_stamp = this_rq->clock;
if (this_rq->avg_idle < sysctl_sched_migration_cost)
return;
for_each_domain(this_cpu, sd) {
unsigned long interval;
@ -4443,8 +4456,10 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
interval = msecs_to_jiffies(sd->balance_interval);
if (time_after(next_balance, sd->last_balance + interval))
next_balance = sd->last_balance + interval;
if (pulled_task)
if (pulled_task) {
this_rq->idle_stamp = 0;
break;
}
}
if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
/*
@ -5046,8 +5061,13 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime,
p->gtime = cputime_add(p->gtime, cputime);
/* Add guest time to cpustat. */
cpustat->user = cputime64_add(cpustat->user, tmp);
cpustat->guest = cputime64_add(cpustat->guest, tmp);
if (TASK_NICE(p) > 0) {
cpustat->nice = cputime64_add(cpustat->nice, tmp);
cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp);
} else {
cpustat->user = cputime64_add(cpustat->user, tmp);
cpustat->guest = cputime64_add(cpustat->guest, tmp);
}
}
/*
@ -5162,61 +5182,87 @@ void account_idle_ticks(unsigned long ticks)
* Use precise platform statistics if available:
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
cputime_t task_utime(struct task_struct *p)
void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
{
return p->utime;
*ut = p->utime;
*st = p->stime;
}
cputime_t task_stime(struct task_struct *p)
void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
{
return p->stime;
struct task_cputime cputime;
thread_group_cputime(p, &cputime);
*ut = cputime.utime;
*st = cputime.stime;
}
#else
cputime_t task_utime(struct task_struct *p)
#ifndef nsecs_to_cputime
# define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs)
#endif
void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
{
clock_t utime = cputime_to_clock_t(p->utime),
total = utime + cputime_to_clock_t(p->stime);
u64 temp;
cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime);
/*
* Use CFS's precise accounting:
*/
temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
if (total) {
temp *= utime;
u64 temp;
temp = (u64)(rtime * utime);
do_div(temp, total);
}
utime = (clock_t)temp;
p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
return p->prev_utime;
}
cputime_t task_stime(struct task_struct *p)
{
clock_t stime;
utime = (cputime_t)temp;
} else
utime = rtime;
/*
* Use CFS's precise accounting. (we subtract utime from
* the total, to make sure the total observed by userspace
* grows monotonically - apps rely on that):
* Compare with previous values, to keep monotonicity:
*/
stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
cputime_to_clock_t(task_utime(p));
p->prev_utime = max(p->prev_utime, utime);
p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime));
if (stime >= 0)
p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
*ut = p->prev_utime;
*st = p->prev_stime;
}
return p->prev_stime;
/*
* Must be called with siglock held.
*/
void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
{
struct signal_struct *sig = p->signal;
struct task_cputime cputime;
cputime_t rtime, utime, total;
thread_group_cputime(p, &cputime);
total = cputime_add(cputime.utime, cputime.stime);
rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
if (total) {
u64 temp;
temp = (u64)(rtime * cputime.utime);
do_div(temp, total);
utime = (cputime_t)temp;
} else
utime = rtime;
sig->prev_utime = max(sig->prev_utime, utime);
sig->prev_stime = max(sig->prev_stime,
cputime_sub(rtime, sig->prev_utime));
*ut = sig->prev_utime;
*st = sig->prev_stime;
}
#endif
inline cputime_t task_gtime(struct task_struct *p)
{
return p->gtime;
}
/*
* This function gets called by the timer code, with HZ frequency.
* We call it with interrupts disabled.
@ -6175,22 +6221,14 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
BUG_ON(p->se.on_rq);
p->policy = policy;
switch (p->policy) {
case SCHED_NORMAL:
case SCHED_BATCH:
case SCHED_IDLE:
p->sched_class = &fair_sched_class;
break;
case SCHED_FIFO:
case SCHED_RR:
p->sched_class = &rt_sched_class;
break;
}
p->rt_priority = prio;
p->normal_prio = normal_prio(p);
/* we are holding p->pi_lock already */
p->prio = rt_mutex_getprio(p);
if (rt_prio(p->prio))
p->sched_class = &rt_sched_class;
else
p->sched_class = &fair_sched_class;
set_load_weight(p);
}
@ -6935,7 +6973,7 @@ void show_state_filter(unsigned long state_filter)
/*
* Only show locks if all tasks are dumped:
*/
if (state_filter == -1)
if (!state_filter)
debug_show_all_locks();
}
@ -7740,6 +7778,16 @@ early_initcall(migration_init);
#ifdef CONFIG_SCHED_DEBUG
static __read_mostly int sched_domain_debug_enabled;
static int __init sched_domain_debug_setup(char *str)
{
sched_domain_debug_enabled = 1;
return 0;
}
early_param("sched_debug", sched_domain_debug_setup);
static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
struct cpumask *groupmask)
{
@ -7826,6 +7874,9 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
cpumask_var_t groupmask;
int level = 0;
if (!sched_domain_debug_enabled)
return;
if (!sd) {
printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
return;
@ -7905,6 +7956,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
static void free_rootdomain(struct root_domain *rd)
{
synchronize_sched();
cpupri_cleanup(&rd->cpupri);
free_cpumask_var(rd->rto_mask);
@ -8045,6 +8098,7 @@ static cpumask_var_t cpu_isolated_map;
/* Setup the mask of cpus configured for isolated domains */
static int __init isolated_cpu_setup(char *str)
{
alloc_bootmem_cpumask_var(&cpu_isolated_map);
cpulist_parse(str, cpu_isolated_map);
return 1;
}
@ -8881,7 +8935,7 @@ static int build_sched_domains(const struct cpumask *cpu_map)
return __build_sched_domains(cpu_map, NULL);
}
static struct cpumask *doms_cur; /* current sched domains */
static cpumask_var_t *doms_cur; /* current sched domains */
static int ndoms_cur; /* number of sched domains in 'doms_cur' */
static struct sched_domain_attr *dattr_cur;
/* attribues of custom domains in 'doms_cur' */
@ -8903,6 +8957,31 @@ int __attribute__((weak)) arch_update_cpu_topology(void)
return 0;
}
cpumask_var_t *alloc_sched_domains(unsigned int ndoms)
{
int i;
cpumask_var_t *doms;
doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL);
if (!doms)
return NULL;
for (i = 0; i < ndoms; i++) {
if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) {
free_sched_domains(doms, i);
return NULL;
}
}
return doms;
}
void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms)
{
unsigned int i;
for (i = 0; i < ndoms; i++)
free_cpumask_var(doms[i]);
kfree(doms);
}
/*
* Set up scheduler domains and groups. Callers must hold the hotplug lock.
* For now this just excludes isolated cpus, but could be used to
@ -8914,12 +8993,12 @@ static int arch_init_sched_domains(const struct cpumask *cpu_map)
arch_update_cpu_topology();
ndoms_cur = 1;
doms_cur = kmalloc(cpumask_size(), GFP_KERNEL);
doms_cur = alloc_sched_domains(ndoms_cur);
if (!doms_cur)
doms_cur = fallback_doms;
cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map);
doms_cur = &fallback_doms;
cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map);
dattr_cur = NULL;
err = build_sched_domains(doms_cur);
err = build_sched_domains(doms_cur[0]);
register_sched_domain_sysctl();
return err;
@ -8969,19 +9048,19 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
* doms_new[] to the current sched domain partitioning, doms_cur[].
* It destroys each deleted domain and builds each new domain.
*
* 'doms_new' is an array of cpumask's of length 'ndoms_new'.
* 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'.
* The masks don't intersect (don't overlap.) We should setup one
* sched domain for each mask. CPUs not in any of the cpumasks will
* not be load balanced. If the same cpumask appears both in the
* current 'doms_cur' domains and in the new 'doms_new', we can leave
* it as it is.
*
* The passed in 'doms_new' should be kmalloc'd. This routine takes
* ownership of it and will kfree it when done with it. If the caller
* failed the kmalloc call, then it can pass in doms_new == NULL &&
* ndoms_new == 1, and partition_sched_domains() will fallback to
* the single partition 'fallback_doms', it also forces the domains
* to be rebuilt.
* The passed in 'doms_new' should be allocated using
* alloc_sched_domains. This routine takes ownership of it and will
* free_sched_domains it when done with it. If the caller failed the
* alloc call, then it can pass in doms_new == NULL && ndoms_new == 1,
* and partition_sched_domains() will fallback to the single partition
* 'fallback_doms', it also forces the domains to be rebuilt.
*
* If doms_new == NULL it will be replaced with cpu_online_mask.
* ndoms_new == 0 is a special case for destroying existing domains,
@ -8989,8 +9068,7 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
*
* Call with hotplug lock held
*/
/* FIXME: Change to struct cpumask *doms_new[] */
void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
struct sched_domain_attr *dattr_new)
{
int i, j, n;
@ -9009,40 +9087,40 @@ void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
/* Destroy deleted domains */
for (i = 0; i < ndoms_cur; i++) {
for (j = 0; j < n && !new_topology; j++) {
if (cpumask_equal(&doms_cur[i], &doms_new[j])
if (cpumask_equal(doms_cur[i], doms_new[j])
&& dattrs_equal(dattr_cur, i, dattr_new, j))
goto match1;
}
/* no match - a current sched domain not in new doms_new[] */
detach_destroy_domains(doms_cur + i);
detach_destroy_domains(doms_cur[i]);
match1:
;
}
if (doms_new == NULL) {
ndoms_cur = 0;
doms_new = fallback_doms;
cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map);
doms_new = &fallback_doms;
cpumask_andnot(doms_new[0], cpu_online_mask, cpu_isolated_map);
WARN_ON_ONCE(dattr_new);
}
/* Build new domains */
for (i = 0; i < ndoms_new; i++) {
for (j = 0; j < ndoms_cur && !new_topology; j++) {
if (cpumask_equal(&doms_new[i], &doms_cur[j])
if (cpumask_equal(doms_new[i], doms_cur[j])
&& dattrs_equal(dattr_new, i, dattr_cur, j))
goto match2;
}
/* no match - add a new doms_new */
__build_sched_domains(doms_new + i,
__build_sched_domains(doms_new[i],
dattr_new ? dattr_new + i : NULL);
match2:
;
}
/* Remember the new sched domains */
if (doms_cur != fallback_doms)
kfree(doms_cur);
if (doms_cur != &fallback_doms)
free_sched_domains(doms_cur, ndoms_cur);
kfree(dattr_cur); /* kfree(NULL) is safe */
doms_cur = doms_new;
dattr_cur = dattr_new;
@ -9364,10 +9442,6 @@ void __init sched_init(void)
#ifdef CONFIG_CPUMASK_OFFSTACK
alloc_size += num_possible_cpus() * cpumask_size();
#endif
/*
* As sched_init() is called before page_alloc is setup,
* we use alloc_bootmem().
*/
if (alloc_size) {
ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
@ -9522,6 +9596,8 @@ void __init sched_init(void)
rq->cpu = i;
rq->online = 0;
rq->migration_thread = NULL;
rq->idle_stamp = 0;
rq->avg_idle = 2*sysctl_sched_migration_cost;
INIT_LIST_HEAD(&rq->migration_queue);
rq_attach_root(rq, &def_root_domain);
#endif
@ -9571,7 +9647,9 @@ void __init sched_init(void)
zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
#endif
zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
/* May be allocated at isolcpus cmdline parse time */
if (cpu_isolated_map == NULL)
zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
#endif /* SMP */
perf_event_init();

4
kernel/sched_debug.c
View File

@ -285,12 +285,16 @@ static void print_cpu(struct seq_file *m, int cpu)
#ifdef CONFIG_SCHEDSTATS
#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
#define P64(n) SEQ_printf(m, " .%-30s: %Ld\n", #n, rq->n);
P(yld_count);
P(sched_switch);
P(sched_count);
P(sched_goidle);
#ifdef CONFIG_SMP
P64(avg_idle);
#endif
P(ttwu_count);
P(ttwu_local);

65
kernel/sched_fair.c
View File

@ -1344,6 +1344,37 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
return idlest;
}
/*
* Try and locate an idle CPU in the sched_domain.
*/
static int
select_idle_sibling(struct task_struct *p, struct sched_domain *sd, int target)
{
int cpu = smp_processor_id();
int prev_cpu = task_cpu(p);
int i;
/*
* If this domain spans both cpu and prev_cpu (see the SD_WAKE_AFFINE
* test in select_task_rq_fair) and the prev_cpu is idle then that's
* always a better target than the current cpu.
*/
if (target == cpu && !cpu_rq(prev_cpu)->cfs.nr_running)
return prev_cpu;
/*
* Otherwise, iterate the domain and find an elegible idle cpu.
*/
for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) {
if (!cpu_rq(i)->cfs.nr_running) {
target = i;
break;
}
}
return target;
}
/*
* sched_balance_self: balance the current task (running on cpu) in domains
* that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
@ -1398,11 +1429,35 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
want_sd = 0;
}
if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
/*
* While iterating the domains looking for a spanning
* WAKE_AFFINE domain, adjust the affine target to any idle cpu
* in cache sharing domains along the way.
*/
if (want_affine) {
int target = -1;
affine_sd = tmp;
want_affine = 0;
/*
* If both cpu and prev_cpu are part of this domain,
* cpu is a valid SD_WAKE_AFFINE target.
*/
if (cpumask_test_cpu(prev_cpu, sched_domain_span(tmp)))
target = cpu;
/*
* If there's an idle sibling in this domain, make that
* the wake_affine target instead of the current cpu.
*/
if (tmp->flags & SD_PREFER_SIBLING)
target = select_idle_sibling(p, tmp, target);
if (target >= 0) {
if (tmp->flags & SD_WAKE_AFFINE) {
affine_sd = tmp;
want_affine = 0;
}
cpu = target;
}
}
if (!want_sd && !want_affine)
@ -1679,7 +1734,7 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
struct cfs_rq *cfs_rq = &rq->cfs;
struct sched_entity *se;
if (unlikely(!cfs_rq->nr_running))
if (!cfs_rq->nr_running)
return NULL;
do {

59
kernel/sched_rt.c
View File

@ -1153,29 +1153,12 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
static inline int pick_optimal_cpu(int this_cpu,
const struct cpumask *mask)
{
int first;
/* "this_cpu" is cheaper to preempt than a remote processor */
if ((this_cpu != -1) && cpumask_test_cpu(this_cpu, mask))
return this_cpu;
first = cpumask_first(mask);
if (first < nr_cpu_ids)
return first;
return -1;
}
static int find_lowest_rq(struct task_struct *task)
{
struct sched_domain *sd;
struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
cpumask_var_t domain_mask;
if (task->rt.nr_cpus_allowed == 1)
return -1; /* No other targets possible */
@ -1198,28 +1181,26 @@ static int find_lowest_rq(struct task_struct *task)
* Otherwise, we consult the sched_domains span maps to figure
* out which cpu is logically closest to our hot cache data.
*/
if (this_cpu == cpu)
this_cpu = -1; /* Skip this_cpu opt if the same */
if (!cpumask_test_cpu(this_cpu, lowest_mask))
this_cpu = -1; /* Skip this_cpu opt if not among lowest */
if (alloc_cpumask_var(&domain_mask, GFP_ATOMIC)) {
for_each_domain(cpu, sd) {
if (sd->flags & SD_WAKE_AFFINE) {
int best_cpu;
for_each_domain(cpu, sd) {
if (sd->flags & SD_WAKE_AFFINE) {
int best_cpu;
cpumask_and(domain_mask,
sched_domain_span(sd),
lowest_mask);
/*
* "this_cpu" is cheaper to preempt than a
* remote processor.
*/
if (this_cpu != -1 &&
cpumask_test_cpu(this_cpu, sched_domain_span(sd)))
return this_cpu;
best_cpu = pick_optimal_cpu(this_cpu,
domain_mask);
if (best_cpu != -1) {
free_cpumask_var(domain_mask);
return best_cpu;
}
}
best_cpu = cpumask_first_and(lowest_mask,
sched_domain_span(sd));
if (best_cpu < nr_cpu_ids)
return best_cpu;
}
free_cpumask_var(domain_mask);
}
/*
@ -1227,7 +1208,13 @@ static int find_lowest_rq(struct task_struct *task)
* just give the caller *something* to work with from the compatible
* locations.
*/
return pick_optimal_cpu(this_cpu, lowest_mask);
if (this_cpu != -1)
return this_cpu;
cpu = cpumask_any(lowest_mask);
if (cpu < nr_cpu_ids)
return cpu;
return -1;
}
/* Will lock the rq it finds */

21
kernel/sys.c
View File

@ -911,16 +911,15 @@ change_okay:
void do_sys_times(struct tms *tms)
{
struct task_cputime cputime;
cputime_t cutime, cstime;
cputime_t tgutime, tgstime, cutime, cstime;
thread_group_cputime(current, &cputime);
spin_lock_irq(&current->sighand->siglock);
thread_group_times(current, &tgutime, &tgstime);
cutime = current->signal->cutime;
cstime = current->signal->cstime;
spin_unlock_irq(&current->sighand->siglock);
tms->tms_utime = cputime_to_clock_t(cputime.utime);
tms->tms_stime = cputime_to_clock_t(cputime.stime);
tms->tms_utime = cputime_to_clock_t(tgutime);
tms->tms_stime = cputime_to_clock_t(tgstime);
tms->tms_cutime = cputime_to_clock_t(cutime);
tms->tms_cstime = cputime_to_clock_t(cstime);
}
@ -1338,16 +1337,14 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
{
struct task_struct *t;
unsigned long flags;
cputime_t utime, stime;
struct task_cputime cputime;
cputime_t tgutime, tgstime, utime, stime;
unsigned long maxrss = 0;
memset((char *) r, 0, sizeof *r);
utime = stime = cputime_zero;
if (who == RUSAGE_THREAD) {
utime = task_utime(current);
stime = task_stime(current);
task_times(current, &utime, &stime);
accumulate_thread_rusage(p, r);
maxrss = p->signal->maxrss;
goto out;
@ -1373,9 +1370,9 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
break;
case RUSAGE_SELF:
thread_group_cputime(p, &cputime);
utime = cputime_add(utime, cputime.utime);
stime = cputime_add(stime, cputime.stime);
thread_group_times(p, &tgutime, &tgstime);
utime = cputime_add(utime, tgutime);
stime = cputime_add(stime, tgstime);
r->ru_nvcsw += p->signal->nvcsw;
r->ru_nivcsw += p->signal->nivcsw;
r->ru_minflt += p->signal->min_flt;

30
kernel/time.c
View File

@ -662,6 +662,36 @@ u64 nsec_to_clock_t(u64 x)
#endif
}
/**
* nsecs_to_jiffies - Convert nsecs in u64 to jiffies
*
* @n: nsecs in u64
*
* Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
* And this doesn't return MAX_JIFFY_OFFSET since this function is designed
* for scheduler, not for use in device drivers to calculate timeout value.
*
* note:
* NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
* ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
*/
unsigned long nsecs_to_jiffies(u64 n)
{
#if (NSEC_PER_SEC % HZ) == 0
/* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */
return div_u64(n, NSEC_PER_SEC / HZ);
#elif (HZ % 512) == 0
/* overflow after 292 years if HZ = 1024 */
return div_u64(n * HZ / 512, NSEC_PER_SEC / 512);
#else
/*
* Generic case - optimized for cases where HZ is a multiple of 3.
* overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc.
*/
return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ);
#endif
}
#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void)
{