diff options
Diffstat (limited to 'kernel/sched/cputime.c')
| -rw-r--r-- | kernel/sched/cputime.c | 53 |
1 files changed, 30 insertions, 23 deletions
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index b2ab2ffb1adc..75f98c5498d5 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -262,21 +262,21 @@ static __always_inline bool steal_account_process_tick(void) #ifdef CONFIG_PARAVIRT if (static_key_false(¶virt_steal_enabled)) { u64 steal; - cputime_t steal_ct; + unsigned long steal_jiffies; steal = paravirt_steal_clock(smp_processor_id()); steal -= this_rq()->prev_steal_time; /* - * cputime_t may be less precise than nsecs (eg: if it's - * based on jiffies). Lets cast the result to cputime + * steal is in nsecs but our caller is expecting steal + * time in jiffies. Lets cast the result to jiffies * granularity and account the rest on the next rounds. */ - steal_ct = nsecs_to_cputime(steal); - this_rq()->prev_steal_time += cputime_to_nsecs(steal_ct); + steal_jiffies = nsecs_to_jiffies(steal); + this_rq()->prev_steal_time += jiffies_to_nsecs(steal_jiffies); - account_steal_time(steal_ct); - return steal_ct; + account_steal_time(jiffies_to_cputime(steal_jiffies)); + return steal_jiffies; } #endif return false; @@ -668,26 +668,25 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime #endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN -static unsigned long long vtime_delta(struct task_struct *tsk) +static cputime_t vtime_delta(struct task_struct *tsk) { - unsigned long long clock; + unsigned long now = READ_ONCE(jiffies); - clock = local_clock(); - if (clock < tsk->vtime_snap) + if (time_before(now, (unsigned long)tsk->vtime_snap)) return 0; - return clock - tsk->vtime_snap; + return jiffies_to_cputime(now - tsk->vtime_snap); } static cputime_t get_vtime_delta(struct task_struct *tsk) { - unsigned long long delta = vtime_delta(tsk); + unsigned long now = READ_ONCE(jiffies); + unsigned long delta = now - tsk->vtime_snap; WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_INACTIVE); - tsk->vtime_snap += delta; + tsk->vtime_snap = now; - /* CHECKME: always safe to convert nsecs to cputime? */ - return nsecs_to_cputime(delta); + return jiffies_to_cputime(delta); } static void __vtime_account_system(struct task_struct *tsk) @@ -699,6 +698,9 @@ static void __vtime_account_system(struct task_struct *tsk) void vtime_account_system(struct task_struct *tsk) { + if (!vtime_delta(tsk)) + return; + write_seqcount_begin(&tsk->vtime_seqcount); __vtime_account_system(tsk); write_seqcount_end(&tsk->vtime_seqcount); @@ -707,7 +709,8 @@ void vtime_account_system(struct task_struct *tsk) void vtime_gen_account_irq_exit(struct task_struct *tsk) { write_seqcount_begin(&tsk->vtime_seqcount); - __vtime_account_system(tsk); + if (vtime_delta(tsk)) + __vtime_account_system(tsk); if (context_tracking_in_user()) tsk->vtime_snap_whence = VTIME_USER; write_seqcount_end(&tsk->vtime_seqcount); @@ -718,16 +721,19 @@ void vtime_account_user(struct task_struct *tsk) cputime_t delta_cpu; write_seqcount_begin(&tsk->vtime_seqcount); - delta_cpu = get_vtime_delta(tsk); tsk->vtime_snap_whence = VTIME_SYS; - account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu)); + if (vtime_delta(tsk)) { + delta_cpu = get_vtime_delta(tsk); + account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu)); + } write_seqcount_end(&tsk->vtime_seqcount); } void vtime_user_enter(struct task_struct *tsk) { write_seqcount_begin(&tsk->vtime_seqcount); - __vtime_account_system(tsk); + if (vtime_delta(tsk)) + __vtime_account_system(tsk); tsk->vtime_snap_whence = VTIME_USER; write_seqcount_end(&tsk->vtime_seqcount); } @@ -742,7 +748,8 @@ void vtime_guest_enter(struct task_struct *tsk) * that can thus safely catch up with a tickless delta. */ write_seqcount_begin(&tsk->vtime_seqcount); - __vtime_account_system(tsk); + if (vtime_delta(tsk)) + __vtime_account_system(tsk); current->flags |= PF_VCPU; write_seqcount_end(&tsk->vtime_seqcount); } @@ -772,7 +779,7 @@ void arch_vtime_task_switch(struct task_struct *prev) write_seqcount_begin(¤t->vtime_seqcount); current->vtime_snap_whence = VTIME_SYS; - current->vtime_snap = sched_clock_cpu(smp_processor_id()); + current->vtime_snap = jiffies; write_seqcount_end(¤t->vtime_seqcount); } @@ -783,7 +790,7 @@ void vtime_init_idle(struct task_struct *t, int cpu) local_irq_save(flags); write_seqcount_begin(&t->vtime_seqcount); t->vtime_snap_whence = VTIME_SYS; - t->vtime_snap = sched_clock_cpu(cpu); + t->vtime_snap = jiffies; write_seqcount_end(&t->vtime_seqcount); local_irq_restore(flags); } |