2019-07-19 02:43:29

by Alex Shi

[permalink] [raw]
Subject: [PATCH v2 1/2] cputime: remove rq parameter for irqtime_account_process_tick func

Using the per cpu rq in function directly is enough, don't need get and
pass it from outside as a parameter. That's make function neat.

Signed-off-by: Alex Shi <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Wanpeng Li <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
---
kernel/sched/cputime.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 2305ce89a26c..3aaf761ede81 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -355,7 +355,7 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
* 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, int ticks)
+ int ticks)
{
u64 other, cputime = TICK_NSEC * ticks;

@@ -381,7 +381,7 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
account_system_index_time(p, cputime, CPUTIME_SOFTIRQ);
} else if (user_tick) {
account_user_time(p, cputime);
- } else if (p == rq->idle) {
+ } else if (p == this_rq()->idle) {
account_idle_time(cputime);
} else if (p->flags & PF_VCPU) { /* System time or guest time */
account_guest_time(p, cputime);
@@ -392,14 +392,12 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,

static void irqtime_account_idle_ticks(int ticks)
{
- struct rq *rq = this_rq();
-
- irqtime_account_process_tick(current, 0, rq, ticks);
+ irqtime_account_process_tick(current, 0, ticks);
}
#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, int nr_ticks) { }
+ int nr_ticks) { }
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */

/*
@@ -475,13 +473,12 @@ void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st)
void account_process_tick(struct task_struct *p, int user_tick)
{
u64 cputime, steal;
- struct rq *rq = this_rq();

if (vtime_accounting_cpu_enabled())
return;

if (sched_clock_irqtime) {
- irqtime_account_process_tick(p, user_tick, rq, 1);
+ irqtime_account_process_tick(p, user_tick, 1);
return;
}

@@ -495,7 +492,7 @@ void account_process_tick(struct task_struct *p, int user_tick)

if (user_tick)
account_user_time(p, cputime);
- else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
+ else if ((p != this_rq()->idle) || (irq_count() != HARDIRQ_OFFSET))
account_system_time(p, HARDIRQ_OFFSET, cputime);
else
account_idle_time(cputime);
--
2.19.1.856.g8858448bb


2019-07-19 02:43:59

by Alex Shi

[permalink] [raw]
Subject: [PATCH v2 2/2] cputime: remove duplicate code in account_process_tick

The irqtime_account_process_tick path was introduced for precise ns irq
time account from commit abb74cefa9c682fb (sched: Export ns irqtimes through
/proc/stat) while account_process_tick still use jiffes. This divide
isn't neccessary especially now both pathes are ns precison.

Move out the irqtime_account_process_tick func from IRQ_TIME_ACCOUNTING.
So it do generally same things as account_process_tick whenever if
IRQ_TIME_ACCOUNTING set or if sched_clock_irqtime enabled.

Signed-off-by: Alex Shi <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Wanpeng Li <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
---
kernel/sched/cputime.c | 26 ++------------------------
1 file changed, 2 insertions(+), 24 deletions(-)

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 3aaf761ede81..6116f50e1f37 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -332,7 +332,6 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
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
@@ -390,14 +389,13 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
}
}

+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
static void irqtime_account_idle_ticks(int ticks)
{
irqtime_account_process_tick(current, 0, ticks);
}
#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,
- int nr_ticks) { }
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */

/*
@@ -472,30 +470,10 @@ void thread_group_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st)
*/
void account_process_tick(struct task_struct *p, int user_tick)
{
- u64 cputime, steal;
-
if (vtime_accounting_cpu_enabled())
return;

- if (sched_clock_irqtime) {
- irqtime_account_process_tick(p, user_tick, 1);
- return;
- }
-
- cputime = TICK_NSEC;
- steal = steal_account_process_time(ULONG_MAX);
-
- if (steal >= cputime)
- return;
-
- cputime -= steal;
-
- if (user_tick)
- account_user_time(p, cputime);
- else if ((p != this_rq()->idle) || (irq_count() != HARDIRQ_OFFSET))
- account_system_time(p, HARDIRQ_OFFSET, cputime);
- else
- account_idle_time(cputime);
+ irqtime_account_process_tick(p, user_tick, 1);
}

/*
--
2.19.1.856.g8858448bb

2019-07-19 08:12:49

by Peter Zijlstra

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] cputime: remove rq parameter for irqtime_account_process_tick func

On Fri, Jul 19, 2019 at 10:42:41AM +0800, Alex Shi wrote:
> Using the per cpu rq in function directly is enough, don't need get and
> pass it from outside as a parameter. That's make function neat.

Please look at code-gen; I'm thinking this patch makes things worse.

2019-07-22 07:46:04

by Alex Shi

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] cputime: remove rq parameter for irqtime_account_process_tick func



?? 2019/7/19 ????4:11, Peter Zijlstra ะด??:
> On Fri, Jul 19, 2019 at 10:42:41AM +0800, Alex Shi wrote:
>> Using the per cpu rq in function directly is enough, don't need get and
>> pass it from outside as a parameter. That's make function neat.
>
> Please look at code-gen; I'm thinking this patch makes things worse.
>

Thanks a lot, Peter!

This patch reference one more time on this_rq(), that do increase cputime.o size. I will move it after access_process_tick() patch in v3. That could resovle the problem and decreases objfile's size on each of patches.

Thanks
Alex