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sched/cputime: Move the vtime task fields to their own struct 

We are about to add vtime accumulation fields to the task struct. Let's
avoid more bloatification and gather vtime information to their own
struct.

Tested-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1498756511-11714-5-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Frederic Weisbecker 2017-06-29 19:15:10 +02:00 committed by Ingo Molnar
parent 60a9ce57e7
commit bac5b6b6b1
4 changed files with 86 additions and 64 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/init_task.h
View File

@ -170,9 +170,9 @@ extern struct cred init_cred;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
# define INIT_VTIME(tsk) \
.vtime_seqcount = SEQCNT_ZERO(tsk.vtime_seqcount), \
.vtime_starttime = 0, \
.vtime_state = VTIME_SYS,
.vtime.seqcount = SEQCNT_ZERO(tsk.vtime.seqcount), \
.vtime.starttime = 0, \
.vtime.state = VTIME_SYS,
#else
# define INIT_VTIME(tsk)
#endif

26
include/linux/sched.h
View File

@ -223,6 +223,21 @@ struct task_cputime {
#define prof_exp stime
#define sched_exp sum_exec_runtime
enum vtime_state {
/* Task is sleeping or running in a CPU with VTIME inactive: */
VTIME_INACTIVE = 0,
/* Task runs in userspace in a CPU with VTIME active: */
VTIME_USER,
/* Task runs in kernelspace in a CPU with VTIME active: */
VTIME_SYS,
};
struct vtime {
seqcount_t seqcount;
unsigned long long starttime;
enum vtime_state state;
};
struct sched_info {
#ifdef CONFIG_SCHED_INFO
/* Cumulative counters: */
@ -688,16 +703,7 @@ struct task_struct {
u64 gtime;
struct prev_cputime prev_cputime;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
seqcount_t vtime_seqcount;
unsigned long long vtime_starttime;
enum {
/* Task is sleeping or running in a CPU with VTIME inactive: */
VTIME_INACTIVE = 0,
/* Task runs in userspace in a CPU with VTIME active: */
VTIME_USER,
/* Task runs in kernelspace in a CPU with VTIME active: */
VTIME_SYS,
} vtime_state;
struct vtime vtime;
#endif
#ifdef CONFIG_NO_HZ_FULL

6
kernel/fork.c
View File

@ -1637,9 +1637,9 @@ static __latent_entropy struct task_struct *copy_process(
prev_cputime_init(&p->prev_cputime);
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
seqcount_init(&p->vtime_seqcount);
p->vtime_starttime = 0;
p->vtime_state = VTIME_INACTIVE;
seqcount_init(&p->vtime.seqcount);
p->vtime.starttime = 0;
p->vtime.state = VTIME_INACTIVE;
#endif
#if defined(SPLIT_RSS_COUNTING)

112
kernel/sched/cputime.c
View File

@ -679,17 +679,17 @@ void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st)
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
static u64 vtime_delta(struct task_struct *tsk)
static u64 vtime_delta(struct vtime *vtime)
{
unsigned long now = READ_ONCE(jiffies);
if (time_before(now, (unsigned long)tsk->vtime_starttime))
if (time_before(now, (unsigned long)vtime->starttime))
return 0;
return jiffies_to_nsecs(now - tsk->vtime_starttime);
return jiffies_to_nsecs(now - vtime->starttime);
}
static u64 get_vtime_delta(struct task_struct *tsk)
static u64 get_vtime_delta(struct vtime *vtime)
{
unsigned long now = READ_ONCE(jiffies);
u64 delta, other;
@ -701,49 +701,56 @@ static u64 get_vtime_delta(struct task_struct *tsk)
* elapsed time. Limit account_other_time to prevent rounding
* errors from causing elapsed vtime to go negative.
*/
delta = jiffies_to_nsecs(now - tsk->vtime_starttime);
delta = jiffies_to_nsecs(now - vtime->starttime);
other = account_other_time(delta);
WARN_ON_ONCE(tsk->vtime_state == VTIME_INACTIVE);
tsk->vtime_starttime = now;
WARN_ON_ONCE(vtime->state == VTIME_INACTIVE);
vtime->starttime = now;
return delta - other;
}
static void __vtime_account_system(struct task_struct *tsk)
{
account_system_time(tsk, irq_count(), get_vtime_delta(tsk));
account_system_time(tsk, irq_count(), get_vtime_delta(&tsk->vtime));
}
void vtime_account_system(struct task_struct *tsk)
{
if (!vtime_delta(tsk))
struct vtime *vtime = &tsk->vtime;
if (!vtime_delta(vtime))
return;
write_seqcount_begin(&tsk->vtime_seqcount);
write_seqcount_begin(&vtime->seqcount);
__vtime_account_system(tsk);
write_seqcount_end(&tsk->vtime_seqcount);
write_seqcount_end(&vtime->seqcount);
}
void vtime_user_enter(struct task_struct *tsk)
{
write_seqcount_begin(&tsk->vtime_seqcount);
if (vtime_delta(tsk))
struct vtime *vtime = &tsk->vtime;
write_seqcount_begin(&vtime->seqcount);
if (vtime_delta(vtime))
__vtime_account_system(tsk);
tsk->vtime_snap_whence = VTIME_USER;
write_seqcount_end(&tsk->vtime_seqcount);
vtime->state = VTIME_USER;
write_seqcount_end(&vtime->seqcount);
}
void vtime_user_exit(struct task_struct *tsk)
{
write_seqcount_begin(&tsk->vtime_seqcount);
if (vtime_delta(tsk))
account_user_time(tsk, get_vtime_delta(tsk));
tsk->vtime_snap_whence = VTIME_SYS;
write_seqcount_end(&tsk->vtime_seqcount);
struct vtime *vtime = &tsk->vtime;
write_seqcount_begin(&vtime->seqcount);
if (vtime_delta(vtime))
account_user_time(tsk, get_vtime_delta(vtime));
vtime->state = VTIME_SYS;
write_seqcount_end(&vtime->seqcount);
}
void vtime_guest_enter(struct task_struct *tsk)
{
struct vtime *vtime = &tsk->vtime;
/*
* The flags must be updated under the lock with
* the vtime_starttime flush and update.
@ -751,54 +758,62 @@ void vtime_guest_enter(struct task_struct *tsk)
* synchronization against the reader (task_gtime())
* that can thus safely catch up with a tickless delta.
*/
write_seqcount_begin(&tsk->vtime_seqcount);
if (vtime_delta(tsk))
write_seqcount_begin(&vtime->seqcount);
if (vtime_delta(vtime))
__vtime_account_system(tsk);
current->flags |= PF_VCPU;
write_seqcount_end(&tsk->vtime_seqcount);
write_seqcount_end(&vtime->seqcount);
}
EXPORT_SYMBOL_GPL(vtime_guest_enter);
void vtime_guest_exit(struct task_struct *tsk)
{
write_seqcount_begin(&tsk->vtime_seqcount);
struct vtime *vtime = &tsk->vtime;
write_seqcount_begin(&vtime->seqcount);
__vtime_account_system(tsk);
current->flags &= ~PF_VCPU;
write_seqcount_end(&tsk->vtime_seqcount);
write_seqcount_end(&vtime->seqcount);
}
EXPORT_SYMBOL_GPL(vtime_guest_exit);
void vtime_account_idle(struct task_struct *tsk)
{
account_idle_time(get_vtime_delta(tsk));
account_idle_time(get_vtime_delta(&tsk->vtime));
}
void arch_vtime_task_switch(struct task_struct *prev)
{
write_seqcount_begin(&prev->vtime_seqcount);
prev->vtime_state = VTIME_INACTIVE;
write_seqcount_end(&prev->vtime_seqcount);
struct vtime *vtime = &prev->vtime;
write_seqcount_begin(&current->vtime_seqcount);
current->vtime_state = VTIME_SYS;
current->vtime_starttime = jiffies;
write_seqcount_end(&current->vtime_seqcount);
write_seqcount_begin(&vtime->seqcount);
vtime->state = VTIME_INACTIVE;
write_seqcount_end(&vtime->seqcount);
vtime = &current->vtime;
write_seqcount_begin(&vtime->seqcount);
vtime->state = VTIME_SYS;
vtime->starttime = jiffies;
write_seqcount_end(&vtime->seqcount);
}
void vtime_init_idle(struct task_struct *t, int cpu)
{
struct vtime *vtime = &t->vtime;
unsigned long flags;
local_irq_save(flags);
write_seqcount_begin(&t->vtime_seqcount);
t->vtime_state = VTIME_SYS;
t->vtime_starttime = jiffies;
write_seqcount_end(&t->vtime_seqcount);
write_seqcount_begin(&vtime->seqcount);
vtime->state = VTIME_SYS;
vtime->starttime = jiffies;
write_seqcount_end(&vtime->seqcount);
local_irq_restore(flags);
}
u64 task_gtime(struct task_struct *t)
{
struct vtime *vtime = &t->vtime;
unsigned int seq;
u64 gtime;
@ -806,13 +821,13 @@ u64 task_gtime(struct task_struct *t)
return t->gtime;
do {
seq = read_seqcount_begin(&t->vtime_seqcount);
seq = read_seqcount_begin(&vtime->seqcount);
gtime = t->gtime;
if (t->vtime_state == VTIME_SYS && t->flags & PF_VCPU)
gtime += vtime_delta(t);
if (vtime->state == VTIME_SYS && t->flags & PF_VCPU)
gtime += vtime_delta(vtime);
} while (read_seqcount_retry(&t->vtime_seqcount, seq));
} while (read_seqcount_retry(&vtime->seqcount, seq));
return gtime;
}
@ -824,8 +839,9 @@ u64 task_gtime(struct task_struct *t)
*/
void task_cputime(struct task_struct *t, u64 *utime, u64 *stime)
{
u64 delta;
struct vtime *vtime = &t->vtime;
unsigned int seq;
u64 delta;
if (!vtime_accounting_enabled()) {
*utime = t->utime;
@ -834,25 +850,25 @@ void task_cputime(struct task_struct *t, u64 *utime, u64 *stime)
}
do {
seq = read_seqcount_begin(&t->vtime_seqcount);
seq = read_seqcount_begin(&vtime->seqcount);
*utime = t->utime;
*stime = t->stime;
/* Task is sleeping, nothing to add */
if (t->vtime_state == VTIME_INACTIVE || is_idle_task(t))
if (vtime->state == VTIME_INACTIVE || is_idle_task(t))
continue;
delta = vtime_delta(t);
delta = vtime_delta(vtime);
/*
* Task runs either in user or kernel space, add pending nohz time to
* the right place.
*/
if (t->vtime_state == VTIME_USER || t->flags & PF_VCPU)
if (vtime->state == VTIME_USER || t->flags & PF_VCPU)
*utime += delta;
else if (t->vtime_state == VTIME_SYS)
else if (vtime->state == VTIME_SYS)
*stime += delta;
} while (read_seqcount_retry(&t->vtime_seqcount, seq));
} while (read_seqcount_retry(&vtime->seqcount, seq));
}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */