[PATCH 0/3] Fix and cleanup and extend cpu.stat

[PATCH 0/3] Fix and cleanup and extend cpu.stat

[Abel Wu]

Patch 1: fixes an issue that forceidle time can be inconsistant with
other cputimes.

Patch 2: cleans up the #ifdef mess in cpu.stat.

Patch 3: extend run_delay accounting to cgroup to show how severely
a cgroup is stalled.

Abel Wu (3):
  cgroup/rstat: Fix forceidle time in cpu.stat
  cgroup/rstat: Cleanup cpu.stat once for all
  cgroup/rstat: Add run_delay accounting for cgroups

 Documentation/admin-guide/cgroup-v2.rst |  1 +
 include/linux/cgroup-defs.h             |  3 +
 include/linux/kernel_stat.h             | 14 +++++
 kernel/cgroup/rstat.c                   | 74 +++++++++++++++----------
 kernel/sched/cputime.c                  | 12 ++++
 kernel/sched/stats.h                    |  2 +
 6 files changed, 78 insertions(+), 28 deletions(-)

-- 
2.37.3

[PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[Abel Wu]

The commit b824766504e4 ("cgroup/rstat: add force idle show helper")
retrieves forceidle_time outside cgroup_rstat_lock for non-root cgroups
which can be potentially inconsistent with other stats.

Rather than reverting that commit, fix it in a way that retains the
effort of cleaning up the ifdef-messes.

Fixes: b824766504e4 ("cgroup/rstat: add force idle show helper")
Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
---
 kernel/cgroup/rstat.c | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
index 5877974ece92..c2784c317cdd 100644
--- a/kernel/cgroup/rstat.c
+++ b/kernel/cgroup/rstat.c
@@ -613,36 +613,33 @@ static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat
 void cgroup_base_stat_cputime_show(struct seq_file *seq)
 {
 	struct cgroup *cgrp = seq_css(seq)->cgroup;
-	u64 usage, utime, stime, ntime;
+	struct cgroup_base_stat bstat;
 
 	if (cgroup_parent(cgrp)) {
 		cgroup_rstat_flush_hold(cgrp);
-		usage = cgrp->bstat.cputime.sum_exec_runtime;
+		bstat = cgrp->bstat;
 		cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime,
-			       &utime, &stime);
-		ntime = cgrp->bstat.ntime;
+			       &bstat.cputime.utime, &bstat.cputime.stime);
 		cgroup_rstat_flush_release(cgrp);
 	} else {
-		/* cgrp->bstat of root is not actually used, reuse it */
-		root_cgroup_cputime(&cgrp->bstat);
-		usage = cgrp->bstat.cputime.sum_exec_runtime;
-		utime = cgrp->bstat.cputime.utime;
-		stime = cgrp->bstat.cputime.stime;
-		ntime = cgrp->bstat.ntime;
+		root_cgroup_cputime(&bstat);
 	}
 
-	do_div(usage, NSEC_PER_USEC);
-	do_div(utime, NSEC_PER_USEC);
-	do_div(stime, NSEC_PER_USEC);
-	do_div(ntime, NSEC_PER_USEC);
+	do_div(bstat.cputime.sum_exec_runtime, NSEC_PER_USEC);
+	do_div(bstat.cputime.utime, NSEC_PER_USEC);
+	do_div(bstat.cputime.stime, NSEC_PER_USEC);
+	do_div(bstat.ntime, NSEC_PER_USEC);
 
 	seq_printf(seq, "usage_usec %llu\n"
 			"user_usec %llu\n"
 			"system_usec %llu\n"
 			"nice_usec %llu\n",
-			usage, utime, stime, ntime);
+			bstat.cputime.sum_exec_runtime,
+			bstat.cputime.utime,
+			bstat.cputime.stime,
+			bstat.ntime);
 
-	cgroup_force_idle_show(seq, &cgrp->bstat);
+	cgroup_force_idle_show(seq, &bstat);
 }
 
 /* Add bpf kfuncs for cgroup_rstat_updated() and cgroup_rstat_flush() */
-- 
2.37.3

Re: [PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[chenridong]

On 2025/1/24 1:47, Abel Wu wrote:
> The commit b824766504e4 ("cgroup/rstat: add force idle show helper")
> retrieves forceidle_time outside cgroup_rstat_lock for non-root cgroups
> which can be potentially inconsistent with other stats.
> 
> Rather than reverting that commit, fix it in a way that retains the
> effort of cleaning up the ifdef-messes.
> 
> Fixes: b824766504e4 ("cgroup/rstat: add force idle show helper")
> Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
> ---
>  kernel/cgroup/rstat.c | 29 +++++++++++++----------------
>  1 file changed, 13 insertions(+), 16 deletions(-)
> 
> diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
> index 5877974ece92..c2784c317cdd 100644
> --- a/kernel/cgroup/rstat.c
> +++ b/kernel/cgroup/rstat.c
> @@ -613,36 +613,33 @@ static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat
>  void cgroup_base_stat_cputime_show(struct seq_file *seq)
>  {
>  	struct cgroup *cgrp = seq_css(seq)->cgroup;
> -	u64 usage, utime, stime, ntime;
> +	struct cgroup_base_stat bstat;
>  
>  	if (cgroup_parent(cgrp)) {
>  		cgroup_rstat_flush_hold(cgrp);
> -		usage = cgrp->bstat.cputime.sum_exec_runtime;
> +		bstat = cgrp->bstat;

Thank you for finding that.
In my version 2, I used to assign cgrp->bstat to bstat.
This is Tj's comment:
https://lore.kernel.org/linux-kernel/ZoQ2ti7nnz9EJSc3@slm.duckdns.org/

Best regards,
Ridong

>  		cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime,
> -			       &utime, &stime);
> -		ntime = cgrp->bstat.ntime;
> +			       &bstat.cputime.utime, &bstat.cputime.stime);
>  		cgroup_rstat_flush_release(cgrp);
>  	} else {
> -		/* cgrp->bstat of root is not actually used, reuse it */
> -		root_cgroup_cputime(&cgrp->bstat);
> -		usage = cgrp->bstat.cputime.sum_exec_runtime;
> -		utime = cgrp->bstat.cputime.utime;
> -		stime = cgrp->bstat.cputime.stime;
> -		ntime = cgrp->bstat.ntime;
> +		root_cgroup_cputime(&bstat);
>  	}
>  
> -	do_div(usage, NSEC_PER_USEC);
> -	do_div(utime, NSEC_PER_USEC);
> -	do_div(stime, NSEC_PER_USEC);
> -	do_div(ntime, NSEC_PER_USEC);
> +	do_div(bstat.cputime.sum_exec_runtime, NSEC_PER_USEC);
> +	do_div(bstat.cputime.utime, NSEC_PER_USEC);
> +	do_div(bstat.cputime.stime, NSEC_PER_USEC);
> +	do_div(bstat.ntime, NSEC_PER_USEC);
>  
>  	seq_printf(seq, "usage_usec %llu\n"
>  			"user_usec %llu\n"
>  			"system_usec %llu\n"
>  			"nice_usec %llu\n",
> -			usage, utime, stime, ntime);
> +			bstat.cputime.sum_exec_runtime,
> +			bstat.cputime.utime,
> +			bstat.cputime.stime,
> +			bstat.ntime);
>  
> -	cgroup_force_idle_show(seq, &cgrp->bstat);
> +	cgroup_force_idle_show(seq, &bstat);
>  }
>  
>  /* Add bpf kfuncs for cgroup_rstat_updated() and cgroup_rstat_flush() */

Re: Re: [PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[Abel Wu]

On 1/24/25 9:47 AM, chenridong Wrote:
> 
> 
> On 2025/1/24 1:47, Abel Wu wrote:
>> The commit b824766504e4 ("cgroup/rstat: add force idle show helper")
>> retrieves forceidle_time outside cgroup_rstat_lock for non-root cgroups
>> which can be potentially inconsistent with other stats.
>>
>> Rather than reverting that commit, fix it in a way that retains the
>> effort of cleaning up the ifdef-messes.
>>
>> Fixes: b824766504e4 ("cgroup/rstat: add force idle show helper")
>> Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
>> ---
>>   kernel/cgroup/rstat.c | 29 +++++++++++++----------------
>>   1 file changed, 13 insertions(+), 16 deletions(-)
>>
>> diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
>> index 5877974ece92..c2784c317cdd 100644
>> --- a/kernel/cgroup/rstat.c
>> +++ b/kernel/cgroup/rstat.c
>> @@ -613,36 +613,33 @@ static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat
>>   void cgroup_base_stat_cputime_show(struct seq_file *seq)
>>   {
>>   	struct cgroup *cgrp = seq_css(seq)->cgroup;
>> -	u64 usage, utime, stime, ntime;
>> +	struct cgroup_base_stat bstat;
>>   
>>   	if (cgroup_parent(cgrp)) {
>>   		cgroup_rstat_flush_hold(cgrp);
>> -		usage = cgrp->bstat.cputime.sum_exec_runtime;
>> +		bstat = cgrp->bstat;
> 
> Thank you for finding that.
> In my version 2, I used to assign cgrp->bstat to bstat.
> This is Tj's comment:
> https://lore.kernel.org/linux-kernel/ZoQ2ti7nnz9EJSc3@slm.duckdns.org/

Thanks for pointing out. Using memcpy() is fine for me, but I see
cgroup_base_stat_flush() is using the same pattern, and if we don't
want copy like this, it would be better unify them in a separate
patch.

But IMHO in either way, I don't think reading forceidle time outside
cgroup_rstat_lock is the right thing to do.

Best Regards,
	Abel

Re: Re: [PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[Tejun Heo]

On Fri, Jan 24, 2025 at 03:49:16PM +0800, Abel Wu wrote:
...
> > > --- a/kernel/cgroup/rstat.c
> > > +++ b/kernel/cgroup/rstat.c
> > > @@ -613,36 +613,33 @@ static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat
> > >   void cgroup_base_stat_cputime_show(struct seq_file *seq)
> > >   {
> > >   	struct cgroup *cgrp = seq_css(seq)->cgroup;
> > > -	u64 usage, utime, stime, ntime;
> > > +	struct cgroup_base_stat bstat;
> > >   	if (cgroup_parent(cgrp)) {
> > >   		cgroup_rstat_flush_hold(cgrp);
> > > -		usage = cgrp->bstat.cputime.sum_exec_runtime;
> > > +		bstat = cgrp->bstat;
> > 
> > Thank you for finding that.
> > In my version 2, I used to assign cgrp->bstat to bstat.
> > This is Tj's comment:
> > https://lore.kernel.org/linux-kernel/ZoQ2ti7nnz9EJSc3@slm.duckdns.org/

I wasn't saying that memcpy() should be used instead of assignment. I was
saying that if a non-trivial struct can be pointed to instead of being
copied, it should be pointed to. If all the fields need to be snapshotted,
assigning is fine.

Thanks.

-- 
tejun

Re: Re: Re: [PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[Abel Wu]

On 1/25/25 7:49 AM, Tejun Heo Wrote:
> On Fri, Jan 24, 2025 at 03:49:16PM +0800, Abel Wu wrote:
> ...
>>>> --- a/kernel/cgroup/rstat.c
>>>> +++ b/kernel/cgroup/rstat.c
>>>> @@ -613,36 +613,33 @@ static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat
>>>>    void cgroup_base_stat_cputime_show(struct seq_file *seq)
>>>>    {
>>>>    	struct cgroup *cgrp = seq_css(seq)->cgroup;
>>>> -	u64 usage, utime, stime, ntime;
>>>> +	struct cgroup_base_stat bstat;
>>>>    	if (cgroup_parent(cgrp)) {
>>>>    		cgroup_rstat_flush_hold(cgrp);
>>>> -		usage = cgrp->bstat.cputime.sum_exec_runtime;
>>>> +		bstat = cgrp->bstat;
>>>
>>> Thank you for finding that.
>>> In my version 2, I used to assign cgrp->bstat to bstat.
>>> This is Tj's comment:
>>> https://lore.kernel.org/linux-kernel/ZoQ2ti7nnz9EJSc3@slm.duckdns.org/
> 
> I wasn't saying that memcpy() should be used instead of assignment. I was
> saying that if a non-trivial struct can be pointed to instead of being
> copied, it should be pointed to. If all the fields need to be snapshotted,
> assigning is fine.

Thanks for your clarification, Tejun. I will post v2 to address Michal's
comments.

Best Regards,
	Abel

Re: [PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[Michal Koutný]

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Hello.

On Fri, Jan 24, 2025 at 01:47:01AM +0800, Abel Wu <wuyun.abel@bytedance.com> wrote:
> The commit b824766504e4 ("cgroup/rstat: add force idle show helper")
> retrieves forceidle_time outside cgroup_rstat_lock for non-root cgroups
> which can be potentially inconsistent with other stats.
> 
> Rather than reverting that commit, fix it in a way that retains the
> effort of cleaning up the ifdef-messes.

Sorry, I'm blind, where's the change moving wrt cgroup_rstat_lock?
(I only see unuse of root cgroup's bstat and a few renames).

Thanks,
Michal

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Re: [PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[Abel Wu]

On 1/24/25 5:22 PM, Michal Koutný Wrote:
> Hello.
> 
> On Fri, Jan 24, 2025 at 01:47:01AM +0800, Abel Wu <wuyun.abel@bytedance.com> wrote:
>> The commit b824766504e4 ("cgroup/rstat: add force idle show helper")
>> retrieves forceidle_time outside cgroup_rstat_lock for non-root cgroups
>> which can be potentially inconsistent with other stats.
>>
>> Rather than reverting that commit, fix it in a way that retains the
>> effort of cleaning up the ifdef-messes.
> 
> Sorry, I'm blind, where's the change moving wrt cgroup_rstat_lock?
> (I only see unuse of root cgroup's bstat and a few renames).

Hi Michal,

The following hunk deleted the snapshot of cgrp->bstat.forceidle_sum:

  	if (cgroup_parent(cgrp)) {
  		cgroup_rstat_flush_hold(cgrp);
  		usage = cgrp->bstat.cputime.sum_exec_runtime;
  		cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime,
  			       &utime, &stime);
-#ifdef CONFIG_SCHED_CORE
-		forceidle_time = cgrp->bstat.forceidle_sum;
-#endif
  		cgroup_rstat_flush_release(cgrp);
  	} else {

and then read forceidle_sum from @cgrp directly outside of the lock,
but its value can be changed in this window, so...
  
-#ifdef CONFIG_SCHED_CORE
-	seq_printf(seq, "core_sched.force_idle_usec %llu\n", forceidle_time);
-#endif
+	cgroup_force_idle_show(seq, &cgrp->bstat);
  }
  
result in the inconsistence between forceidle and other cputimes.

Best Regards,
	Abel

Re: [PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[Michal Koutný]

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On Fri, Jan 24, 2025 at 05:58:26PM +0800, Abel Wu <wuyun.abel@bytedance.com> wrote:
> The following hunk deleted the snapshot of cgrp->bstat.forceidle_sum:

But there's no such hunk in your PATCH 1/3 :-o

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Re: [PATCH 1/3] cgroup/rstat: Fix forceidle time in cpu.stat

[Abel Wu]

On 1/24/25 6:39 PM, Michal Koutný Wrote:
> On Fri, Jan 24, 2025 at 05:58:26PM +0800, Abel Wu <wuyun.abel@bytedance.com> wrote:
>> The following hunk deleted the snapshot of cgrp->bstat.forceidle_sum:
> 
> But there's no such hunk in your PATCH 1/3 :-o

  	if (cgroup_parent(cgrp)) {
  		cgroup_rstat_flush_hold(cgrp);
-		usage = cgrp->bstat.cputime.sum_exec_runtime;
+		bstat = cgrp->bstat;
  		cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime,
-			       &utime, &stime);
-		ntime = cgrp->bstat.ntime;
+			       &bstat.cputime.utime, &bstat.cputime.stime);
  		cgroup_rstat_flush_release(cgrp);
  	} else {

Because @bstat takes a full snapshot of @cgrp->bstat which contains
forceidle time. I think the lack of readability is the reason why
TJ doesn't like this :(

[PATCH 2/3] cgroup/rstat: Cleanup cpu.stat once for all

[Abel Wu]

There were efforts like b824766504e4 ("cgroup/rstat: add force idle show helper")
to escape from #ifdef hells, and there could be new stats coming out in
the future, let's clean it up once for all.

Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
---
 kernel/cgroup/rstat.c | 46 +++++++++++++++++++++++--------------------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
index c2784c317cdd..6ad647f3e241 100644
--- a/kernel/cgroup/rstat.c
+++ b/kernel/cgroup/rstat.c
@@ -599,21 +599,38 @@ static void root_cgroup_cputime(struct cgroup_base_stat *bstat)
 	}
 }
 
+static struct bstat_entry {
+	const char	*name;
+	const int	offset;
+} bstats[] = {
+#define BSTAT_ENTRY(name, field)	\
+	{ name, offsetof(struct cgroup_base_stat, field) }
+	BSTAT_ENTRY("usage_usec",	cputime.sum_exec_runtime),
+	BSTAT_ENTRY("user_usec",	cputime.utime),
+	BSTAT_ENTRY("system_usec",	cputime.stime),
+	BSTAT_ENTRY("nice_usec",	ntime),
+#ifdef CONFIG_SCHED_CORE
+	BSTAT_ENTRY("core_sched.force_idle_usec", forceidle_sum),
+#endif
+	{ NULL } /* must be at end */
+#undef BSTAT_ENTRY
+};
 
-static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat *bstat)
+static void __append_bstat(struct seq_file *seq, struct cgroup_base_stat *bstat,
+			   struct bstat_entry *entry)
 {
-#ifdef CONFIG_SCHED_CORE
-	u64 forceidle_time = bstat->forceidle_sum;
+	u64 *val;
 
-	do_div(forceidle_time, NSEC_PER_USEC);
-	seq_printf(seq, "core_sched.force_idle_usec %llu\n", forceidle_time);
-#endif
+	val = (void *)bstat + entry->offset;
+	do_div(*val, NSEC_PER_USEC);
+	seq_printf(seq, "%s %llu\n", entry->name, *val);
 }
 
 void cgroup_base_stat_cputime_show(struct seq_file *seq)
 {
 	struct cgroup *cgrp = seq_css(seq)->cgroup;
 	struct cgroup_base_stat bstat;
+	struct bstat_entry *e;
 
 	if (cgroup_parent(cgrp)) {
 		cgroup_rstat_flush_hold(cgrp);
@@ -625,21 +642,8 @@ void cgroup_base_stat_cputime_show(struct seq_file *seq)
 		root_cgroup_cputime(&bstat);
 	}
 
-	do_div(bstat.cputime.sum_exec_runtime, NSEC_PER_USEC);
-	do_div(bstat.cputime.utime, NSEC_PER_USEC);
-	do_div(bstat.cputime.stime, NSEC_PER_USEC);
-	do_div(bstat.ntime, NSEC_PER_USEC);
-
-	seq_printf(seq, "usage_usec %llu\n"
-			"user_usec %llu\n"
-			"system_usec %llu\n"
-			"nice_usec %llu\n",
-			bstat.cputime.sum_exec_runtime,
-			bstat.cputime.utime,
-			bstat.cputime.stime,
-			bstat.ntime);
-
-	cgroup_force_idle_show(seq, &bstat);
+	for (e = bstats; e->name; e++)
+		__append_bstat(seq, &bstat, e);
 }
 
 /* Add bpf kfuncs for cgroup_rstat_updated() and cgroup_rstat_flush() */
-- 
2.37.3

Re: [PATCH 2/3] cgroup/rstat: Cleanup cpu.stat once for all

[Michal Koutný]

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On Fri, Jan 24, 2025 at 01:47:02AM +0800, Abel Wu <wuyun.abel@bytedance.com> wrote:
> -static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat *bstat)
> +static void __append_bstat(struct seq_file *seq, struct cgroup_base_stat *bstat,
> +			   struct bstat_entry *entry)

Not sure if starting with double underscore is needed when the helper is
`static`. Also something like s/append/show/ -> cgroup_bstat_entry_show.

Thanks,
Michal

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Re: [PATCH 2/3] cgroup/rstat: Cleanup cpu.stat once for all

[Abel Wu]

On 1/24/25 5:22 PM, Michal Koutný Wrote:
> On Fri, Jan 24, 2025 at 01:47:02AM +0800, Abel Wu <wuyun.abel@bytedance.com> wrote:
>> -static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat *bstat)
>> +static void __append_bstat(struct seq_file *seq, struct cgroup_base_stat *bstat,
>> +			   struct bstat_entry *entry)
> 
> Not sure if starting with double underscore is needed when the helper is
> `static`. Also something like s/append/show/ -> cgroup_bstat_entry_show.

Yeah, "cgroup_bstat_entry_show" looks better! Will fix.

Thanks,
	Abel

[PATCH 3/3] cgroup/rstat: Add run_delay accounting for cgroups

[Abel Wu]

The per-task and per-cpu accounting have already been tracked by
t->sched_info.run_delay and rq->rq_sched_info.run_delay respectively.
Extends this to also include cgroups.

The PSI indicator, "some" of cpu.pressure, loses the insight into how
severely that cgroup is stalled. Say 100 tasks or just 1 task that gets
stalled at a certain point will show no difference in "some" pressure.
IOW "some" is a flat value that not weighted by the severity (e.g. # of
tasks).

Only cgroup v2 is supported. Similar to the task accounting, the cgroup
accounting requires that CONFIG_SCHED_INFO is enabled.

Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
---
 Documentation/admin-guide/cgroup-v2.rst |  1 +
 include/linux/cgroup-defs.h             |  3 +++
 include/linux/kernel_stat.h             | 14 ++++++++++++++
 kernel/cgroup/rstat.c                   | 17 +++++++++++++++++
 kernel/sched/cputime.c                  | 12 ++++++++++++
 kernel/sched/stats.h                    |  2 ++
 6 files changed, 49 insertions(+)

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 315ede811c9d..440c3800c49c 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1100,6 +1100,7 @@ All time durations are in microseconds.
 	- usage_usec
 	- user_usec
 	- system_usec
+	- run_delay_usec	(requires CONFIG_SCHED_INFO)
 
 	and the following five when the controller is enabled:
 
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 1b20d2d8ef7c..287366e60414 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -328,6 +328,9 @@ struct cgroup_base_stat {
 	u64 forceidle_sum;
 #endif
 	u64 ntime;
+#ifdef CONFIG_SCHED_INFO
+	u64 run_delay;
+#endif
 };
 
 /*
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index b97ce2df376f..256b1a55de62 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -31,6 +31,15 @@ enum cpu_usage_stat {
 	CPUTIME_FORCEIDLE,
 #endif
 	NR_STATS,
+
+#ifdef CONFIG_SCHED_INFO
+	/*
+	 * Instead of cputime, run_delay is tracked through
+	 * sched_info by task and rq, so there is no need to
+	 * enlarge the cpustat[] array.
+	 */
+	CPUTIME_RUN_DELAY,
+#endif
 };
 
 struct kernel_cpustat {
@@ -141,4 +150,9 @@ extern void account_idle_ticks(unsigned long ticks);
 extern void __account_forceidle_time(struct task_struct *tsk, u64 delta);
 #endif
 
+#ifdef CONFIG_SCHED_INFO
+extern void account_run_delay_time(struct task_struct *tsk, u64 delta);
+extern u64 get_cpu_run_delay(int cpu);
+#endif
+
 #endif /* _LINUX_KERNEL_STAT_H */
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
index 6ad647f3e241..6a365a7fb7b8 100644
--- a/kernel/cgroup/rstat.c
+++ b/kernel/cgroup/rstat.c
@@ -445,6 +445,9 @@ static void cgroup_base_stat_add(struct cgroup_base_stat *dst_bstat,
 	dst_bstat->forceidle_sum += src_bstat->forceidle_sum;
 #endif
 	dst_bstat->ntime += src_bstat->ntime;
+#ifdef CONFIG_SCHED_INFO
+	dst_bstat->run_delay += src_bstat->run_delay;
+#endif
 }
 
 static void cgroup_base_stat_sub(struct cgroup_base_stat *dst_bstat,
@@ -457,6 +460,9 @@ static void cgroup_base_stat_sub(struct cgroup_base_stat *dst_bstat,
 	dst_bstat->forceidle_sum -= src_bstat->forceidle_sum;
 #endif
 	dst_bstat->ntime -= src_bstat->ntime;
+#ifdef CONFIG_SCHED_INFO
+	dst_bstat->run_delay -= src_bstat->run_delay;
+#endif
 }
 
 static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu)
@@ -551,6 +557,11 @@ void __cgroup_account_cputime_field(struct cgroup *cgrp,
 	case CPUTIME_FORCEIDLE:
 		rstatc->bstat.forceidle_sum += delta_exec;
 		break;
+#endif
+#ifdef CONFIG_SCHED_INFO
+	case CPUTIME_RUN_DELAY:
+		rstatc->bstat.run_delay += delta_exec;
+		break;
 #endif
 	default:
 		break;
@@ -596,6 +607,9 @@ static void root_cgroup_cputime(struct cgroup_base_stat *bstat)
 		bstat->forceidle_sum += cpustat[CPUTIME_FORCEIDLE];
 #endif
 		bstat->ntime += cpustat[CPUTIME_NICE];
+#ifdef CONFIG_SCHED_INFO
+		bstat->run_delay += get_cpu_run_delay(i);
+#endif
 	}
 }
 
@@ -611,6 +625,9 @@ static struct bstat_entry {
 	BSTAT_ENTRY("nice_usec",	ntime),
 #ifdef CONFIG_SCHED_CORE
 	BSTAT_ENTRY("core_sched.force_idle_usec", forceidle_sum),
+#endif
+#ifdef CONFIG_SCHED_INFO
+	BSTAT_ENTRY("run_delay_usec",	run_delay),
 #endif
 	{ NULL } /* must be at end */
 #undef BSTAT_ENTRY
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 5d9143dd0879..e6be57cdb54e 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -243,6 +243,18 @@ void __account_forceidle_time(struct task_struct *p, u64 delta)
 }
 #endif
 
+#ifdef CONFIG_SCHED_INFO
+void account_run_delay_time(struct task_struct *p, u64 delta)
+{
+	cgroup_account_cputime_field(p, CPUTIME_RUN_DELAY, delta);
+}
+
+u64 get_cpu_run_delay(int cpu)
+{
+	return cpu_rq(cpu)->rq_sched_info.run_delay;
+}
+#endif
+
 /*
  * When a guest is interrupted for a longer amount of time, missed clock
  * ticks are not redelivered later. Due to that, this function may on
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index 6ade91bce63e..b21a2c4b9c54 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -249,6 +249,7 @@ static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t)
 	t->sched_info.last_queued = 0;
 	t->sched_info.run_delay += delta;
 
+	account_run_delay_time(t, delta);
 	rq_sched_info_dequeue(rq, delta);
 }
 
@@ -271,6 +272,7 @@ static void sched_info_arrive(struct rq *rq, struct task_struct *t)
 	t->sched_info.last_arrival = now;
 	t->sched_info.pcount++;
 
+	account_run_delay_time(t, delta);
 	rq_sched_info_arrive(rq, delta);
 }
 
-- 
2.37.3