mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 05:04:00 +08:00
7f6575f1fb
Running the full dynticks cputime accounting with preemptible kernel debugging trigger the following warning: [ 4.488303] BUG: using smp_processor_id() in preemptible [00000000] code: init/1 [ 4.490971] caller is native_sched_clock+0x22/0x80 [ 4.493663] Pid: 1, comm: init Not tainted 3.8.0+ #13 [ 4.496376] Call Trace: [ 4.498996] [<ffffffff813410eb>] debug_smp_processor_id+0xdb/0xf0 [ 4.501716] [<ffffffff8101e642>] native_sched_clock+0x22/0x80 [ 4.504434] [<ffffffff8101db99>] sched_clock+0x9/0x10 [ 4.507185] [<ffffffff81096ccd>] fetch_task_cputime+0xad/0x120 [ 4.509916] [<ffffffff81096dd5>] task_cputime+0x35/0x60 [ 4.512622] [<ffffffff810f146e>] acct_update_integrals+0x1e/0x40 [ 4.515372] [<ffffffff8117d2cf>] do_execve_common+0x4ff/0x5c0 [ 4.518117] [<ffffffff8117cf14>] ? do_execve_common+0x144/0x5c0 [ 4.520844] [<ffffffff81867a10>] ? rest_init+0x160/0x160 [ 4.523554] [<ffffffff8117d457>] do_execve+0x37/0x40 [ 4.526276] [<ffffffff810021a3>] run_init_process+0x23/0x30 [ 4.528953] [<ffffffff81867aac>] kernel_init+0x9c/0xf0 [ 4.531608] [<ffffffff8188356c>] ret_from_fork+0x7c/0xb0 We use sched_clock() to perform and fixup the cputime accounting. However we are calling it with preemption enabled from the read side, which trigger the bug above. To fix this up, use local_clock() instead. It takes care of preemption and also provide a more reliable clock source. This is welcome for this kind of statistic that is widely relied on in userspace. Reported-by: Thomas Gleixner <tglx@linutronix.de> Reported-by: Ingo Molnar <mingo@kernel.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Kevin Hilman <khilman@linaro.org> Link: http://lkml.kernel.org/r/1361636925-22288-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
818 lines
20 KiB
C
818 lines
20 KiB
C
#include <linux/export.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/tsacct_kern.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <linux/static_key.h>
|
|
#include <linux/context_tracking.h>
|
|
#include "sched.h"
|
|
|
|
|
|
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
|
|
|
|
/*
|
|
* There are no locks covering percpu hardirq/softirq time.
|
|
* They are only modified in vtime_account, on corresponding CPU
|
|
* with interrupts disabled. So, writes are safe.
|
|
* They are read and saved off onto struct rq in update_rq_clock().
|
|
* This may result in other CPU reading this CPU's irq time and can
|
|
* race with irq/vtime_account on this CPU. We would either get old
|
|
* or new value with a side effect of accounting a slice of irq time to wrong
|
|
* task when irq is in progress while we read rq->clock. That is a worthy
|
|
* compromise in place of having locks on each irq in account_system_time.
|
|
*/
|
|
DEFINE_PER_CPU(u64, cpu_hardirq_time);
|
|
DEFINE_PER_CPU(u64, cpu_softirq_time);
|
|
|
|
static DEFINE_PER_CPU(u64, irq_start_time);
|
|
static int sched_clock_irqtime;
|
|
|
|
void enable_sched_clock_irqtime(void)
|
|
{
|
|
sched_clock_irqtime = 1;
|
|
}
|
|
|
|
void disable_sched_clock_irqtime(void)
|
|
{
|
|
sched_clock_irqtime = 0;
|
|
}
|
|
|
|
#ifndef CONFIG_64BIT
|
|
DEFINE_PER_CPU(seqcount_t, irq_time_seq);
|
|
#endif /* CONFIG_64BIT */
|
|
|
|
/*
|
|
* Called before incrementing preempt_count on {soft,}irq_enter
|
|
* and before decrementing preempt_count on {soft,}irq_exit.
|
|
*/
|
|
void irqtime_account_irq(struct task_struct *curr)
|
|
{
|
|
unsigned long flags;
|
|
s64 delta;
|
|
int cpu;
|
|
|
|
if (!sched_clock_irqtime)
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
|
|
cpu = smp_processor_id();
|
|
delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time);
|
|
__this_cpu_add(irq_start_time, delta);
|
|
|
|
irq_time_write_begin();
|
|
/*
|
|
* We do not account for softirq time from ksoftirqd here.
|
|
* We want to continue accounting softirq time to ksoftirqd thread
|
|
* in that case, so as not to confuse scheduler with a special task
|
|
* that do not consume any time, but still wants to run.
|
|
*/
|
|
if (hardirq_count())
|
|
__this_cpu_add(cpu_hardirq_time, delta);
|
|
else if (in_serving_softirq() && curr != this_cpu_ksoftirqd())
|
|
__this_cpu_add(cpu_softirq_time, delta);
|
|
|
|
irq_time_write_end();
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(irqtime_account_irq);
|
|
|
|
static int irqtime_account_hi_update(void)
|
|
{
|
|
u64 *cpustat = kcpustat_this_cpu->cpustat;
|
|
unsigned long flags;
|
|
u64 latest_ns;
|
|
int ret = 0;
|
|
|
|
local_irq_save(flags);
|
|
latest_ns = this_cpu_read(cpu_hardirq_time);
|
|
if (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_IRQ])
|
|
ret = 1;
|
|
local_irq_restore(flags);
|
|
return ret;
|
|
}
|
|
|
|
static int irqtime_account_si_update(void)
|
|
{
|
|
u64 *cpustat = kcpustat_this_cpu->cpustat;
|
|
unsigned long flags;
|
|
u64 latest_ns;
|
|
int ret = 0;
|
|
|
|
local_irq_save(flags);
|
|
latest_ns = this_cpu_read(cpu_softirq_time);
|
|
if (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_SOFTIRQ])
|
|
ret = 1;
|
|
local_irq_restore(flags);
|
|
return ret;
|
|
}
|
|
|
|
#else /* CONFIG_IRQ_TIME_ACCOUNTING */
|
|
|
|
#define sched_clock_irqtime (0)
|
|
|
|
#endif /* !CONFIG_IRQ_TIME_ACCOUNTING */
|
|
|
|
static inline void task_group_account_field(struct task_struct *p, int index,
|
|
u64 tmp)
|
|
{
|
|
#ifdef CONFIG_CGROUP_CPUACCT
|
|
struct kernel_cpustat *kcpustat;
|
|
struct cpuacct *ca;
|
|
#endif
|
|
/*
|
|
* Since all updates are sure to touch the root cgroup, we
|
|
* get ourselves ahead and touch it first. If the root cgroup
|
|
* is the only cgroup, then nothing else should be necessary.
|
|
*
|
|
*/
|
|
__get_cpu_var(kernel_cpustat).cpustat[index] += tmp;
|
|
|
|
#ifdef CONFIG_CGROUP_CPUACCT
|
|
if (unlikely(!cpuacct_subsys.active))
|
|
return;
|
|
|
|
rcu_read_lock();
|
|
ca = task_ca(p);
|
|
while (ca && (ca != &root_cpuacct)) {
|
|
kcpustat = this_cpu_ptr(ca->cpustat);
|
|
kcpustat->cpustat[index] += tmp;
|
|
ca = parent_ca(ca);
|
|
}
|
|
rcu_read_unlock();
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Account user cpu time to a process.
|
|
* @p: the process that the cpu time gets accounted to
|
|
* @cputime: the cpu time spent in user space since the last update
|
|
* @cputime_scaled: cputime scaled by cpu frequency
|
|
*/
|
|
void account_user_time(struct task_struct *p, cputime_t cputime,
|
|
cputime_t cputime_scaled)
|
|
{
|
|
int index;
|
|
|
|
/* Add user time to process. */
|
|
p->utime += cputime;
|
|
p->utimescaled += cputime_scaled;
|
|
account_group_user_time(p, cputime);
|
|
|
|
index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
|
|
|
|
/* Add user time to cpustat. */
|
|
task_group_account_field(p, index, (__force u64) cputime);
|
|
|
|
/* Account for user time used */
|
|
acct_account_cputime(p);
|
|
}
|
|
|
|
/*
|
|
* Account guest cpu time to a process.
|
|
* @p: the process that the cpu time gets accounted to
|
|
* @cputime: the cpu time spent in virtual machine since the last update
|
|
* @cputime_scaled: cputime scaled by cpu frequency
|
|
*/
|
|
static void account_guest_time(struct task_struct *p, cputime_t cputime,
|
|
cputime_t cputime_scaled)
|
|
{
|
|
u64 *cpustat = kcpustat_this_cpu->cpustat;
|
|
|
|
/* Add guest time to process. */
|
|
p->utime += cputime;
|
|
p->utimescaled += cputime_scaled;
|
|
account_group_user_time(p, cputime);
|
|
p->gtime += cputime;
|
|
|
|
/* Add guest time to cpustat. */
|
|
if (TASK_NICE(p) > 0) {
|
|
cpustat[CPUTIME_NICE] += (__force u64) cputime;
|
|
cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime;
|
|
} else {
|
|
cpustat[CPUTIME_USER] += (__force u64) cputime;
|
|
cpustat[CPUTIME_GUEST] += (__force u64) cputime;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Account system cpu time to a process and desired cpustat field
|
|
* @p: the process that the cpu time gets accounted to
|
|
* @cputime: the cpu time spent in kernel space since the last update
|
|
* @cputime_scaled: cputime scaled by cpu frequency
|
|
* @target_cputime64: pointer to cpustat field that has to be updated
|
|
*/
|
|
static inline
|
|
void __account_system_time(struct task_struct *p, cputime_t cputime,
|
|
cputime_t cputime_scaled, int index)
|
|
{
|
|
/* Add system time to process. */
|
|
p->stime += cputime;
|
|
p->stimescaled += cputime_scaled;
|
|
account_group_system_time(p, cputime);
|
|
|
|
/* Add system time to cpustat. */
|
|
task_group_account_field(p, index, (__force u64) cputime);
|
|
|
|
/* Account for system time used */
|
|
acct_account_cputime(p);
|
|
}
|
|
|
|
/*
|
|
* Account system cpu time to a process.
|
|
* @p: the process that the cpu time gets accounted to
|
|
* @hardirq_offset: the offset to subtract from hardirq_count()
|
|
* @cputime: the cpu time spent in kernel space since the last update
|
|
* @cputime_scaled: cputime scaled by cpu frequency
|
|
*/
|
|
void account_system_time(struct task_struct *p, int hardirq_offset,
|
|
cputime_t cputime, cputime_t cputime_scaled)
|
|
{
|
|
int index;
|
|
|
|
if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
|
|
account_guest_time(p, cputime, cputime_scaled);
|
|
return;
|
|
}
|
|
|
|
if (hardirq_count() - hardirq_offset)
|
|
index = CPUTIME_IRQ;
|
|
else if (in_serving_softirq())
|
|
index = CPUTIME_SOFTIRQ;
|
|
else
|
|
index = CPUTIME_SYSTEM;
|
|
|
|
__account_system_time(p, cputime, cputime_scaled, index);
|
|
}
|
|
|
|
/*
|
|
* Account for involuntary wait time.
|
|
* @cputime: the cpu time spent in involuntary wait
|
|
*/
|
|
void account_steal_time(cputime_t cputime)
|
|
{
|
|
u64 *cpustat = kcpustat_this_cpu->cpustat;
|
|
|
|
cpustat[CPUTIME_STEAL] += (__force u64) cputime;
|
|
}
|
|
|
|
/*
|
|
* Account for idle time.
|
|
* @cputime: the cpu time spent in idle wait
|
|
*/
|
|
void account_idle_time(cputime_t cputime)
|
|
{
|
|
u64 *cpustat = kcpustat_this_cpu->cpustat;
|
|
struct rq *rq = this_rq();
|
|
|
|
if (atomic_read(&rq->nr_iowait) > 0)
|
|
cpustat[CPUTIME_IOWAIT] += (__force u64) cputime;
|
|
else
|
|
cpustat[CPUTIME_IDLE] += (__force u64) cputime;
|
|
}
|
|
|
|
static __always_inline bool steal_account_process_tick(void)
|
|
{
|
|
#ifdef CONFIG_PARAVIRT
|
|
if (static_key_false(¶virt_steal_enabled)) {
|
|
u64 steal, st = 0;
|
|
|
|
steal = paravirt_steal_clock(smp_processor_id());
|
|
steal -= this_rq()->prev_steal_time;
|
|
|
|
st = steal_ticks(steal);
|
|
this_rq()->prev_steal_time += st * TICK_NSEC;
|
|
|
|
account_steal_time(st);
|
|
return st;
|
|
}
|
|
#endif
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Accumulate raw cputime values of dead tasks (sig->[us]time) and live
|
|
* tasks (sum on group iteration) belonging to @tsk's group.
|
|
*/
|
|
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
|
|
{
|
|
struct signal_struct *sig = tsk->signal;
|
|
cputime_t utime, stime;
|
|
struct task_struct *t;
|
|
|
|
times->utime = sig->utime;
|
|
times->stime = sig->stime;
|
|
times->sum_exec_runtime = sig->sum_sched_runtime;
|
|
|
|
rcu_read_lock();
|
|
/* make sure we can trust tsk->thread_group list */
|
|
if (!likely(pid_alive(tsk)))
|
|
goto out;
|
|
|
|
t = tsk;
|
|
do {
|
|
task_cputime(tsk, &utime, &stime);
|
|
times->utime += utime;
|
|
times->stime += stime;
|
|
times->sum_exec_runtime += task_sched_runtime(t);
|
|
} while_each_thread(tsk, t);
|
|
out:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
|
|
/*
|
|
* Account a tick to a process and cpustat
|
|
* @p: the process that the cpu time gets accounted to
|
|
* @user_tick: is the tick from userspace
|
|
* @rq: the pointer to rq
|
|
*
|
|
* Tick demultiplexing follows the order
|
|
* - pending hardirq update
|
|
* - pending softirq update
|
|
* - user_time
|
|
* - idle_time
|
|
* - system time
|
|
* - check for guest_time
|
|
* - else account as system_time
|
|
*
|
|
* Check for hardirq is done both for system and user time as there is
|
|
* no timer going off while we are on hardirq and hence we may never get an
|
|
* opportunity to update it solely in system time.
|
|
* p->stime and friends are only updated on system time and not on irq
|
|
* softirq as those do not count in task exec_runtime any more.
|
|
*/
|
|
static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
|
|
struct rq *rq)
|
|
{
|
|
cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
|
|
u64 *cpustat = kcpustat_this_cpu->cpustat;
|
|
|
|
if (steal_account_process_tick())
|
|
return;
|
|
|
|
if (irqtime_account_hi_update()) {
|
|
cpustat[CPUTIME_IRQ] += (__force u64) cputime_one_jiffy;
|
|
} else if (irqtime_account_si_update()) {
|
|
cpustat[CPUTIME_SOFTIRQ] += (__force u64) cputime_one_jiffy;
|
|
} else if (this_cpu_ksoftirqd() == p) {
|
|
/*
|
|
* ksoftirqd time do not get accounted in cpu_softirq_time.
|
|
* So, we have to handle it separately here.
|
|
* Also, p->stime needs to be updated for ksoftirqd.
|
|
*/
|
|
__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
|
|
CPUTIME_SOFTIRQ);
|
|
} else if (user_tick) {
|
|
account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
|
|
} else if (p == rq->idle) {
|
|
account_idle_time(cputime_one_jiffy);
|
|
} else if (p->flags & PF_VCPU) { /* System time or guest time */
|
|
account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled);
|
|
} else {
|
|
__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
|
|
CPUTIME_SYSTEM);
|
|
}
|
|
}
|
|
|
|
static void irqtime_account_idle_ticks(int ticks)
|
|
{
|
|
int i;
|
|
struct rq *rq = this_rq();
|
|
|
|
for (i = 0; i < ticks; i++)
|
|
irqtime_account_process_tick(current, 0, rq);
|
|
}
|
|
#else /* CONFIG_IRQ_TIME_ACCOUNTING */
|
|
static inline void irqtime_account_idle_ticks(int ticks) {}
|
|
static inline void irqtime_account_process_tick(struct task_struct *p, int user_tick,
|
|
struct rq *rq) {}
|
|
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
|
|
|
|
#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
|
|
/*
|
|
* Account a single tick of cpu time.
|
|
* @p: the process that the cpu time gets accounted to
|
|
* @user_tick: indicates if the tick is a user or a system tick
|
|
*/
|
|
void account_process_tick(struct task_struct *p, int user_tick)
|
|
{
|
|
cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
|
|
struct rq *rq = this_rq();
|
|
|
|
if (vtime_accounting_enabled())
|
|
return;
|
|
|
|
if (sched_clock_irqtime) {
|
|
irqtime_account_process_tick(p, user_tick, rq);
|
|
return;
|
|
}
|
|
|
|
if (steal_account_process_tick())
|
|
return;
|
|
|
|
if (user_tick)
|
|
account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
|
|
else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
|
|
account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
|
|
one_jiffy_scaled);
|
|
else
|
|
account_idle_time(cputime_one_jiffy);
|
|
}
|
|
|
|
/*
|
|
* Account multiple ticks of steal time.
|
|
* @p: the process from which the cpu time has been stolen
|
|
* @ticks: number of stolen ticks
|
|
*/
|
|
void account_steal_ticks(unsigned long ticks)
|
|
{
|
|
account_steal_time(jiffies_to_cputime(ticks));
|
|
}
|
|
|
|
/*
|
|
* Account multiple ticks of idle time.
|
|
* @ticks: number of stolen ticks
|
|
*/
|
|
void account_idle_ticks(unsigned long ticks)
|
|
{
|
|
|
|
if (sched_clock_irqtime) {
|
|
irqtime_account_idle_ticks(ticks);
|
|
return;
|
|
}
|
|
|
|
account_idle_time(jiffies_to_cputime(ticks));
|
|
}
|
|
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
|
|
|
|
/*
|
|
* Use precise platform statistics if available:
|
|
*/
|
|
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
|
|
void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
|
|
{
|
|
*ut = p->utime;
|
|
*st = p->stime;
|
|
}
|
|
|
|
void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
|
|
{
|
|
struct task_cputime cputime;
|
|
|
|
thread_group_cputime(p, &cputime);
|
|
|
|
*ut = cputime.utime;
|
|
*st = cputime.stime;
|
|
}
|
|
|
|
#ifndef __ARCH_HAS_VTIME_TASK_SWITCH
|
|
void vtime_task_switch(struct task_struct *prev)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
if (is_idle_task(prev))
|
|
vtime_account_idle(prev);
|
|
else
|
|
vtime_account_system(prev);
|
|
|
|
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
|
|
vtime_account_user(prev);
|
|
#endif
|
|
arch_vtime_task_switch(prev);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Archs that account the whole time spent in the idle task
|
|
* (outside irq) as idle time can rely on this and just implement
|
|
* vtime_account_system() and vtime_account_idle(). Archs that
|
|
* have other meaning of the idle time (s390 only includes the
|
|
* time spent by the CPU when it's in low power mode) must override
|
|
* vtime_account().
|
|
*/
|
|
#ifndef __ARCH_HAS_VTIME_ACCOUNT
|
|
void vtime_account_irq_enter(struct task_struct *tsk)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
if (!in_interrupt()) {
|
|
/*
|
|
* If we interrupted user, context_tracking_in_user()
|
|
* is 1 because the context tracking don't hook
|
|
* on irq entry/exit. This way we know if
|
|
* we need to flush user time on kernel entry.
|
|
*/
|
|
if (context_tracking_in_user()) {
|
|
vtime_account_user(tsk);
|
|
return;
|
|
}
|
|
|
|
if (is_idle_task(tsk)) {
|
|
vtime_account_idle(tsk);
|
|
return;
|
|
}
|
|
}
|
|
vtime_account_system(tsk);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
|
|
#endif /* __ARCH_HAS_VTIME_ACCOUNT */
|
|
|
|
#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
|
|
|
|
static cputime_t scale_stime(cputime_t stime, cputime_t rtime, cputime_t total)
|
|
{
|
|
u64 temp = (__force u64) rtime;
|
|
|
|
temp *= (__force u64) stime;
|
|
|
|
if (sizeof(cputime_t) == 4)
|
|
temp = div_u64(temp, (__force u32) total);
|
|
else
|
|
temp = div64_u64(temp, (__force u64) total);
|
|
|
|
return (__force cputime_t) temp;
|
|
}
|
|
|
|
/*
|
|
* Adjust tick based cputime random precision against scheduler
|
|
* runtime accounting.
|
|
*/
|
|
static void cputime_adjust(struct task_cputime *curr,
|
|
struct cputime *prev,
|
|
cputime_t *ut, cputime_t *st)
|
|
{
|
|
cputime_t rtime, stime, total;
|
|
|
|
stime = curr->stime;
|
|
total = stime + curr->utime;
|
|
|
|
/*
|
|
* Tick based cputime accounting depend on random scheduling
|
|
* timeslices of a task to be interrupted or not by the timer.
|
|
* Depending on these circumstances, the number of these interrupts
|
|
* may be over or under-optimistic, matching the real user and system
|
|
* cputime with a variable precision.
|
|
*
|
|
* Fix this by scaling these tick based values against the total
|
|
* runtime accounted by the CFS scheduler.
|
|
*/
|
|
rtime = nsecs_to_cputime(curr->sum_exec_runtime);
|
|
|
|
if (total)
|
|
stime = scale_stime(stime, rtime, total);
|
|
else
|
|
stime = rtime;
|
|
|
|
/*
|
|
* If the tick based count grows faster than the scheduler one,
|
|
* the result of the scaling may go backward.
|
|
* Let's enforce monotonicity.
|
|
*/
|
|
prev->stime = max(prev->stime, stime);
|
|
prev->utime = max(prev->utime, rtime - prev->stime);
|
|
|
|
*ut = prev->utime;
|
|
*st = prev->stime;
|
|
}
|
|
|
|
void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
|
|
{
|
|
struct task_cputime cputime = {
|
|
.sum_exec_runtime = p->se.sum_exec_runtime,
|
|
};
|
|
|
|
task_cputime(p, &cputime.utime, &cputime.stime);
|
|
cputime_adjust(&cputime, &p->prev_cputime, ut, st);
|
|
}
|
|
|
|
/*
|
|
* Must be called with siglock held.
|
|
*/
|
|
void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
|
|
{
|
|
struct task_cputime cputime;
|
|
|
|
thread_group_cputime(p, &cputime);
|
|
cputime_adjust(&cputime, &p->signal->prev_cputime, ut, st);
|
|
}
|
|
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
|
|
|
|
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
|
|
static unsigned long long vtime_delta(struct task_struct *tsk)
|
|
{
|
|
unsigned long long clock;
|
|
|
|
clock = local_clock();
|
|
if (clock < tsk->vtime_snap)
|
|
return 0;
|
|
|
|
return clock - tsk->vtime_snap;
|
|
}
|
|
|
|
static cputime_t get_vtime_delta(struct task_struct *tsk)
|
|
{
|
|
unsigned long long delta = vtime_delta(tsk);
|
|
|
|
WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_SLEEPING);
|
|
tsk->vtime_snap += delta;
|
|
|
|
/* CHECKME: always safe to convert nsecs to cputime? */
|
|
return nsecs_to_cputime(delta);
|
|
}
|
|
|
|
static void __vtime_account_system(struct task_struct *tsk)
|
|
{
|
|
cputime_t delta_cpu = get_vtime_delta(tsk);
|
|
|
|
account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu));
|
|
}
|
|
|
|
void vtime_account_system(struct task_struct *tsk)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
__vtime_account_system(tsk);
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_account_irq_exit(struct task_struct *tsk)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
if (context_tracking_in_user())
|
|
tsk->vtime_snap_whence = VTIME_USER;
|
|
__vtime_account_system(tsk);
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_account_user(struct task_struct *tsk)
|
|
{
|
|
cputime_t delta_cpu;
|
|
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
delta_cpu = get_vtime_delta(tsk);
|
|
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
tsk->vtime_snap_whence = VTIME_SYS;
|
|
account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_user_enter(struct task_struct *tsk)
|
|
{
|
|
if (!vtime_accounting_enabled())
|
|
return;
|
|
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
tsk->vtime_snap_whence = VTIME_USER;
|
|
__vtime_account_system(tsk);
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_guest_enter(struct task_struct *tsk)
|
|
{
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
__vtime_account_system(tsk);
|
|
current->flags |= PF_VCPU;
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_guest_exit(struct task_struct *tsk)
|
|
{
|
|
write_seqlock(&tsk->vtime_seqlock);
|
|
__vtime_account_system(tsk);
|
|
current->flags &= ~PF_VCPU;
|
|
write_sequnlock(&tsk->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_account_idle(struct task_struct *tsk)
|
|
{
|
|
cputime_t delta_cpu = get_vtime_delta(tsk);
|
|
|
|
account_idle_time(delta_cpu);
|
|
}
|
|
|
|
bool vtime_accounting_enabled(void)
|
|
{
|
|
return context_tracking_active();
|
|
}
|
|
|
|
void arch_vtime_task_switch(struct task_struct *prev)
|
|
{
|
|
write_seqlock(&prev->vtime_seqlock);
|
|
prev->vtime_snap_whence = VTIME_SLEEPING;
|
|
write_sequnlock(&prev->vtime_seqlock);
|
|
|
|
write_seqlock(¤t->vtime_seqlock);
|
|
current->vtime_snap_whence = VTIME_SYS;
|
|
current->vtime_snap = sched_clock();
|
|
write_sequnlock(¤t->vtime_seqlock);
|
|
}
|
|
|
|
void vtime_init_idle(struct task_struct *t)
|
|
{
|
|
unsigned long flags;
|
|
|
|
write_seqlock_irqsave(&t->vtime_seqlock, flags);
|
|
t->vtime_snap_whence = VTIME_SYS;
|
|
t->vtime_snap = sched_clock();
|
|
write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
|
|
}
|
|
|
|
cputime_t task_gtime(struct task_struct *t)
|
|
{
|
|
unsigned int seq;
|
|
cputime_t gtime;
|
|
|
|
do {
|
|
seq = read_seqbegin(&t->vtime_seqlock);
|
|
|
|
gtime = t->gtime;
|
|
if (t->flags & PF_VCPU)
|
|
gtime += vtime_delta(t);
|
|
|
|
} while (read_seqretry(&t->vtime_seqlock, seq));
|
|
|
|
return gtime;
|
|
}
|
|
|
|
/*
|
|
* Fetch cputime raw values from fields of task_struct and
|
|
* add up the pending nohz execution time since the last
|
|
* cputime snapshot.
|
|
*/
|
|
static void
|
|
fetch_task_cputime(struct task_struct *t,
|
|
cputime_t *u_dst, cputime_t *s_dst,
|
|
cputime_t *u_src, cputime_t *s_src,
|
|
cputime_t *udelta, cputime_t *sdelta)
|
|
{
|
|
unsigned int seq;
|
|
unsigned long long delta;
|
|
|
|
do {
|
|
*udelta = 0;
|
|
*sdelta = 0;
|
|
|
|
seq = read_seqbegin(&t->vtime_seqlock);
|
|
|
|
if (u_dst)
|
|
*u_dst = *u_src;
|
|
if (s_dst)
|
|
*s_dst = *s_src;
|
|
|
|
/* Task is sleeping, nothing to add */
|
|
if (t->vtime_snap_whence == VTIME_SLEEPING ||
|
|
is_idle_task(t))
|
|
continue;
|
|
|
|
delta = vtime_delta(t);
|
|
|
|
/*
|
|
* Task runs either in user or kernel space, add pending nohz time to
|
|
* the right place.
|
|
*/
|
|
if (t->vtime_snap_whence == VTIME_USER || t->flags & PF_VCPU) {
|
|
*udelta = delta;
|
|
} else {
|
|
if (t->vtime_snap_whence == VTIME_SYS)
|
|
*sdelta = delta;
|
|
}
|
|
} while (read_seqretry(&t->vtime_seqlock, seq));
|
|
}
|
|
|
|
|
|
void task_cputime(struct task_struct *t, cputime_t *utime, cputime_t *stime)
|
|
{
|
|
cputime_t udelta, sdelta;
|
|
|
|
fetch_task_cputime(t, utime, stime, &t->utime,
|
|
&t->stime, &udelta, &sdelta);
|
|
if (utime)
|
|
*utime += udelta;
|
|
if (stime)
|
|
*stime += sdelta;
|
|
}
|
|
|
|
void task_cputime_scaled(struct task_struct *t,
|
|
cputime_t *utimescaled, cputime_t *stimescaled)
|
|
{
|
|
cputime_t udelta, sdelta;
|
|
|
|
fetch_task_cputime(t, utimescaled, stimescaled,
|
|
&t->utimescaled, &t->stimescaled, &udelta, &sdelta);
|
|
if (utimescaled)
|
|
*utimescaled += cputime_to_scaled(udelta);
|
|
if (stimescaled)
|
|
*stimescaled += cputime_to_scaled(sdelta);
|
|
}
|
|
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
|