[PATCH-next v2 0/2] cgroup/cpuset: Run SCHED_DEADLINE shrink test on valid partition root only

[PATCH-next v2 0/2] cgroup/cpuset: Run SCHED_DEADLINE shrink test on valid partition root only

[Waiman Long]

v2:
 - Leave the v1 code as is and switch between using is_cpu_exclusive()
   for v1 and is_partition_valid() for v2.

When testing some upstream cpuset patch, it was found that the current
SCHED_DEADLINE shrink test in validate_change() can incorrectly get
triggered due to the fact that the exclusive flag may get set on a
cpuset that is not a valid partition root. This series fixes this
problem by making sure that the test will only be triggered on a valid
partition root and remove the now unnecessary code to handle the
exclusive flag in the v2 code.

Waiman Long (2):
  cgroup/cpuset: Run SCHED_DEADLINE shrink test on valid partition root
    only
  cgroup/cpuset: Remove CS_CPU_EXCLUSIVE handling code from v2

 kernel/cgroup/cpuset.c | 59 ++++++------------------------------------
 1 file changed, 8 insertions(+), 51 deletions(-)

-- 
2.55.0

[PATCH-next v2 1/2] cgroup/cpuset: Run SCHED_DEADLINE shrink test on valid partition root only

[Waiman Long]

Commit f82f80426f7a ("sched/deadline: Ensure that updates to exclusive
cpusets don't break AC") adds a check in validate_change() to make
sure that there is enough bandwidth for SCHED_DEADLINE tasks if we
shrink a v1 exclusive cpuset that has CS_CPU_EXCLUSIVE flag set.

With the introduction of cpuset partition in cgroup v2, we keep setting
the CS_CPU_EXCLUSIVE flag for a partition root so that the SCHED_DEADLINE
check will continue to work as intended. However it turns out that the
current code isn't perfect and there are cases where a cpuset isn't
a valid partition root, but the exclusive flag is still incorrectly
set. This can leads to SCHED_DEADLINE check being incorrectly triggered
when there are deadline tasks in the system. This can result in unexpected
-EBUSY failure when making changes to cpuset control files. Fix that
by checking for a valid partition root for v2 and is_cpu_exclusive()
for v1. It is far easier and less cumbersome than to make sure that
the exclusive flag is only set for valid partition roots.

Even though commit a86ce68078b2 ("cgroup/cpuset: Extract out
CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling") is marked as a
commit to be fixed, the problem may exist before that.

Fixes: a86ce68078b2 ("cgroup/cpuset: Extract out CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling")
Signed-off-by: Waiman Long <longman@redhat.com>
---
 kernel/cgroup/cpuset.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 753aa65afcd7..104fe10c336d 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -771,8 +771,8 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
 	 * For v1, effective_cpus == cpus_allowed & user_xcpus() returns
 	 * cpus_allowed.
 	 *
-	 * For v2, is_cpu_exclusive() & is_sched_load_balance() are true only
-	 * for non-isolated partition root. At this point, the target
+	 * For v2, is_partition_valid(cur) & is_sched_load_balance() are true
+	 * only for non-isolated partition root. At this point, the target
 	 * effective_cpus isn't computed yet. user_xcpus() is the best
 	 * approximation.
 	 *
@@ -781,7 +781,8 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
 	 * becomes an issue.
 	 */
 	ret = -EBUSY;
-	if (is_cpu_exclusive(cur) && is_sched_load_balance(cur) &&
+	if ((is_partition_valid(cur) || (!cpuset_v2() && is_cpu_exclusive(cur))) &&
+	    is_sched_load_balance(cur) &&
 	    !cpuset_cpumask_can_shrink(cur->effective_cpus, user_xcpus(trial)))
 		goto out;
 
-- 
2.55.0

[PATCH-next v2 2/2] cgroup/cpuset: Remove CS_CPU_EXCLUSIVE handling code from v2

[Waiman Long]

As the is_cpu_exclusive() function is only used for DEADLINE shrink
test with v1 there is no need to have the CS_CPU_EXCLUSIVE flag set on
valid partition root anymore. Remove update_partition_exclusive_flag()
and other CS_CPU_EXCLUSIVE flag handling code in cpuset.c.

Signed-off-by: Waiman Long <longman@redhat.com>
---
 kernel/cgroup/cpuset.c | 52 ++++--------------------------------------
 1 file changed, 4 insertions(+), 48 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 104fe10c336d..4a915da37bb3 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -1174,25 +1174,6 @@ enum partition_cmd {
 static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
 				    struct tmpmasks *tmp);
 
-/*
- * Update partition exclusive flag
- *
- * Return: 0 if successful, an error code otherwise
- */
-static int update_partition_exclusive_flag(struct cpuset *cs, int new_prs)
-{
-	bool exclusive = (new_prs > PRS_MEMBER);
-
-	if (exclusive && !is_cpu_exclusive(cs)) {
-		if (cpuset_update_flag(CS_CPU_EXCLUSIVE, cs, 1))
-			return PERR_NOTEXCL;
-	} else if (!exclusive && is_cpu_exclusive(cs)) {
-		/* Turning off CS_CPU_EXCLUSIVE will not return error */
-		cpuset_update_flag(CS_CPU_EXCLUSIVE, cs, 0);
-	}
-	return 0;
-}
-
 /*
  * Update partition load balance flag and/or rebuild sched domain
  *
@@ -1248,11 +1229,9 @@ static void reset_partition_data(struct cpuset *cs)
 
 	lockdep_assert_held(&callback_lock);
 
-	if (cpumask_empty(cs->exclusive_cpus)) {
+	if (cpumask_empty(cs->exclusive_cpus))
 		cpumask_clear(cs->effective_xcpus);
-		if (is_cpu_exclusive(cs))
-			clear_bit(CS_CPU_EXCLUSIVE, &cs->flags);
-	}
+
 	if (!cpumask_and(cs->effective_cpus, parent->effective_cpus, cs->cpus_allowed))
 		cpumask_copy(cs->effective_cpus, parent->effective_cpus);
 }
@@ -2028,19 +2007,6 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
 	if (!adding && !deleting && (new_prs == old_prs))
 		return 0;
 
-	/*
-	 * Transitioning between invalid to valid or vice versa may require
-	 * changing CS_CPU_EXCLUSIVE. In the case of partcmd_update,
-	 * validate_change() has already been successfully called and
-	 * CPU lists in cs haven't been updated yet. So defer it to later.
-	 */
-	if ((old_prs != new_prs) && (cmd != partcmd_update))  {
-		int err = update_partition_exclusive_flag(cs, new_prs);
-
-		if (err)
-			return err;
-	}
-
 	/*
 	 * Change the parent's effective_cpus & effective_xcpus (top cpuset
 	 * only).
@@ -2063,9 +2029,6 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
 
 	spin_unlock_irq(&callback_lock);
 
-	if ((old_prs != new_prs) && (cmd == partcmd_update))
-		update_partition_exclusive_flag(cs, new_prs);
-
 	if (adding || deleting) {
 		cpuset_update_tasks_cpumask(parent, tmp->addmask);
 		update_sibling_cpumasks(parent, cs, tmp);
@@ -2942,10 +2905,6 @@ static int update_prstate(struct cpuset *cs, int new_prs)
 	if (alloc_tmpmasks(&tmpmask))
 		return -ENOMEM;
 
-	err = update_partition_exclusive_flag(cs, new_prs);
-	if (err)
-		goto out;
-
 	if (!old_prs) {
 		/*
 		 * cpus_allowed and exclusive_cpus cannot be both empty.
@@ -3009,13 +2968,10 @@ static int update_prstate(struct cpuset *cs, int new_prs)
 	}
 out:
 	/*
-	 * Make partition invalid & disable CS_CPU_EXCLUSIVE if an error
-	 * happens.
+	 * Make partition invalid if an error happens.
 	 */
-	if (err) {
+	if (err)
 		new_prs = -new_prs;
-		update_partition_exclusive_flag(cs, new_prs);
-	}
 
 	spin_lock_irq(&callback_lock);
 	cs->partition_root_state = new_prs;
-- 
2.55.0

Re: [PATCH-next v2 1/2] cgroup/cpuset: Run SCHED_DEADLINE shrink test on valid partition root only

[Ridong Chen]

On 9/28/2026 5:53 AM, Waiman Long wrote:
> Commit f82f80426f7a ("sched/deadline: Ensure that updates to exclusive
> cpusets don't break AC") adds a check in validate_change() to make
> sure that there is enough bandwidth for SCHED_DEADLINE tasks if we
> shrink a v1 exclusive cpuset that has CS_CPU_EXCLUSIVE flag set.
> 
> With the introduction of cpuset partition in cgroup v2, we keep setting
> the CS_CPU_EXCLUSIVE flag for a partition root so that the SCHED_DEADLINE
> check will continue to work as intended. However it turns out that the
> current code isn't perfect and there are cases where a cpuset isn't
> a valid partition root, but the exclusive flag is still incorrectly
> set. This can leads to SCHED_DEADLINE check being incorrectly triggered
> when there are deadline tasks in the system. This can result in unexpected
> -EBUSY failure when making changes to cpuset control files. Fix that
> by checking for a valid partition root for v2 and is_cpu_exclusive()
> for v1. It is far easier and less cumbersome than to make sure that
> the exclusive flag is only set for valid partition roots.
> 
> Even though commit a86ce68078b2 ("cgroup/cpuset: Extract out
> CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling") is marked as a
> commit to be fixed, the problem may exist before that.
> 
> Fixes: a86ce68078b2 ("cgroup/cpuset: Extract out CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling")
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
>   kernel/cgroup/cpuset.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 753aa65afcd7..104fe10c336d 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -771,8 +771,8 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
>   	 * For v1, effective_cpus == cpus_allowed & user_xcpus() returns
>   	 * cpus_allowed.
>   	 *
> -	 * For v2, is_cpu_exclusive() & is_sched_load_balance() are true only
> -	 * for non-isolated partition root. At this point, the target
> +	 * For v2, is_partition_valid(cur) & is_sched_load_balance() are true
> +	 * only for non-isolated partition root. At this point, the target
>   	 * effective_cpus isn't computed yet. user_xcpus() is the best
>   	 * approximation.
>   	 *
> @@ -781,7 +781,8 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
>   	 * becomes an issue.
>   	 */
>   	ret = -EBUSY;
> -	if (is_cpu_exclusive(cur) && is_sched_load_balance(cur) &&
> +	if ((is_partition_valid(cur) || (!cpuset_v2() && is_cpu_exclusive(cur))) &&
> +	    is_sched_load_balance(cur) &&
>   	    !cpuset_cpumask_can_shrink(cur->effective_cpus, user_xcpus(trial)))
>   		goto out;
>   
Reviewed-by: Ridong Chen <ridong.chen@linux.dev>
Thanks.
-- 
Best regards
Ridong

Re: [PATCH-next v2 2/2] cgroup/cpuset: Remove CS_CPU_EXCLUSIVE handling code from v2

[Ridong Chen]

On 9/28/2026 5:53 AM, Waiman Long wrote:
> As the is_cpu_exclusive() function is only used for DEADLINE shrink
> test with v1 there is no need to have the CS_CPU_EXCLUSIVE flag set on
> valid partition root anymore. Remove update_partition_exclusive_flag()
> and other CS_CPU_EXCLUSIVE flag handling code in cpuset.c.
> 
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
>   kernel/cgroup/cpuset.c | 52 ++++--------------------------------------
>   1 file changed, 4 insertions(+), 48 deletions(-)
> 
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 104fe10c336d..4a915da37bb3 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -1174,25 +1174,6 @@ enum partition_cmd {
>   static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
>   				    struct tmpmasks *tmp);
>   
> -/*
> - * Update partition exclusive flag
> - *
> - * Return: 0 if successful, an error code otherwise
> - */
> -static int update_partition_exclusive_flag(struct cpuset *cs, int new_prs)
> -{
> -	bool exclusive = (new_prs > PRS_MEMBER);
> -
> -	if (exclusive && !is_cpu_exclusive(cs)) {
> -		if (cpuset_update_flag(CS_CPU_EXCLUSIVE, cs, 1))
> -			return PERR_NOTEXCL;
> -	} else if (!exclusive && is_cpu_exclusive(cs)) {
> -		/* Turning off CS_CPU_EXCLUSIVE will not return error */
> -		cpuset_update_flag(CS_CPU_EXCLUSIVE, cs, 0);
> -	}
> -	return 0;
> -}
> -
>   /*
>    * Update partition load balance flag and/or rebuild sched domain
>    *
> @@ -1248,11 +1229,9 @@ static void reset_partition_data(struct cpuset *cs)
>   
>   	lockdep_assert_held(&callback_lock);
>   
> -	if (cpumask_empty(cs->exclusive_cpus)) {
> +	if (cpumask_empty(cs->exclusive_cpus))
>   		cpumask_clear(cs->effective_xcpus);
> -		if (is_cpu_exclusive(cs))
> -			clear_bit(CS_CPU_EXCLUSIVE, &cs->flags);
> -	}
> +
>   	if (!cpumask_and(cs->effective_cpus, parent->effective_cpus, cs->cpus_allowed))
>   		cpumask_copy(cs->effective_cpus, parent->effective_cpus);
>   }
> @@ -2028,19 +2007,6 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
>   	if (!adding && !deleting && (new_prs == old_prs))
>   		return 0;
>   
> -	/*
> -	 * Transitioning between invalid to valid or vice versa may require
> -	 * changing CS_CPU_EXCLUSIVE. In the case of partcmd_update,
> -	 * validate_change() has already been successfully called and
> -	 * CPU lists in cs haven't been updated yet. So defer it to later.
> -	 */
> -	if ((old_prs != new_prs) && (cmd != partcmd_update))  {
> -		int err = update_partition_exclusive_flag(cs, new_prs);
> -
> -		if (err)
> -			return err;
> -	}
> -
>   	/*
>   	 * Change the parent's effective_cpus & effective_xcpus (top cpuset
>   	 * only).
> @@ -2063,9 +2029,6 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
>   
>   	spin_unlock_irq(&callback_lock);
>   
> -	if ((old_prs != new_prs) && (cmd == partcmd_update))
> -		update_partition_exclusive_flag(cs, new_prs);
> -
>   	if (adding || deleting) {
>   		cpuset_update_tasks_cpumask(parent, tmp->addmask);
>   		update_sibling_cpumasks(parent, cs, tmp);
> @@ -2942,10 +2905,6 @@ static int update_prstate(struct cpuset *cs, int new_prs)
>   	if (alloc_tmpmasks(&tmpmask))
>   		return -ENOMEM;
>   
> -	err = update_partition_exclusive_flag(cs, new_prs);
> -	if (err)
> -		goto out;
> -
>   	if (!old_prs) {
>   		/*
>   		 * cpus_allowed and exclusive_cpus cannot be both empty.
> @@ -3009,13 +2968,10 @@ static int update_prstate(struct cpuset *cs, int new_prs)
>   	}
>   out:
>   	/*
> -	 * Make partition invalid & disable CS_CPU_EXCLUSIVE if an error
> -	 * happens.
> +	 * Make partition invalid if an error happens.
>   	 */
> -	if (err) {
> +	if (err)
>   		new_prs = -new_prs;
> -		update_partition_exclusive_flag(cs, new_prs);
> -	}
>   
>   	spin_lock_irq(&callback_lock);
>   	cs->partition_root_state = new_prs;

Nice.

Reviewed-by: Ridong Chen <ridong.chen@linux.dev>

-- 
Best regards
Ridong

Re: [PATCH-next v2 1/2] cgroup/cpuset: Run SCHED_DEADLINE shrink test on valid partition root only

[Guopeng Zhang]

在 2026/9/28 05:53, Waiman Long 写道:
> Commit f82f80426f7a ("sched/deadline: Ensure that updates to exclusive
> cpusets don't break AC") adds a check in validate_change() to make
> sure that there is enough bandwidth for SCHED_DEADLINE tasks if we
> shrink a v1 exclusive cpuset that has CS_CPU_EXCLUSIVE flag set.
> 
> With the introduction of cpuset partition in cgroup v2, we keep setting
> the CS_CPU_EXCLUSIVE flag for a partition root so that the SCHED_DEADLINE
> check will continue to work as intended. However it turns out that the
> current code isn't perfect and there are cases where a cpuset isn't
> a valid partition root, but the exclusive flag is still incorrectly
> set. This can leads to SCHED_DEADLINE check being incorrectly triggered
> when there are deadline tasks in the system. This can result in unexpected
> -EBUSY failure when making changes to cpuset control files. Fix that
> by checking for a valid partition root for v2 and is_cpu_exclusive()
> for v1. It is far easier and less cumbersome than to make sure that
> the exclusive flag is only set for valid partition roots.
> 
> Even though commit a86ce68078b2 ("cgroup/cpuset: Extract out
> CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling") is marked as a
> commit to be fixed, the problem may exist before that.
> 
> Fixes: a86ce68078b2 ("cgroup/cpuset: Extract out CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling")
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
>  kernel/cgroup/cpuset.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 753aa65afcd7..104fe10c336d 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -771,8 +771,8 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
>  	 * For v1, effective_cpus == cpus_allowed & user_xcpus() returns
>  	 * cpus_allowed.
>  	 *
> -	 * For v2, is_cpu_exclusive() & is_sched_load_balance() are true only
> -	 * for non-isolated partition root. At this point, the target
> +	 * For v2, is_partition_valid(cur) & is_sched_load_balance() are true
> +	 * only for non-isolated partition root. At this point, the target
>  	 * effective_cpus isn't computed yet. user_xcpus() is the best
>  	 * approximation.
>  	 *
> @@ -781,7 +781,8 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
>  	 * becomes an issue.
>  	 */
>  	ret = -EBUSY;
> -	if (is_cpu_exclusive(cur) && is_sched_load_balance(cur) &&
> +	if ((is_partition_valid(cur) || (!cpuset_v2() && is_cpu_exclusive(cur))) &&
> +	    is_sched_load_balance(cur) &&
>  	    !cpuset_cpumask_can_shrink(cur->effective_cpus, user_xcpus(trial)))
>  		goto out;
>  

Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>

Thanks,
Guopeng

Re: [PATCH-next v2 2/2] cgroup/cpuset: Remove CS_CPU_EXCLUSIVE handling code from v2

[Guopeng Zhang]

在 2026/9/28 05:53, Waiman Long 写道:
> As the is_cpu_exclusive() function is only used for DEADLINE shrink
> test with v1 there is no need to have the CS_CPU_EXCLUSIVE flag set on
> valid partition root anymore. Remove update_partition_exclusive_flag()
> and other CS_CPU_EXCLUSIVE flag handling code in cpuset.c.
> 
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
>  kernel/cgroup/cpuset.c | 52 ++++--------------------------------------
>  1 file changed, 4 insertions(+), 48 deletions(-)
> 
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 104fe10c336d..4a915da37bb3 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -1174,25 +1174,6 @@ enum partition_cmd {
>  static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
>  				    struct tmpmasks *tmp);
>  
> -/*
> - * Update partition exclusive flag
> - *
> - * Return: 0 if successful, an error code otherwise
> - */
> -static int update_partition_exclusive_flag(struct cpuset *cs, int new_prs)
> -{
> -	bool exclusive = (new_prs > PRS_MEMBER);
> -
> -	if (exclusive && !is_cpu_exclusive(cs)) {
> -		if (cpuset_update_flag(CS_CPU_EXCLUSIVE, cs, 1))
> -			return PERR_NOTEXCL;
> -	} else if (!exclusive && is_cpu_exclusive(cs)) {
> -		/* Turning off CS_CPU_EXCLUSIVE will not return error */
> -		cpuset_update_flag(CS_CPU_EXCLUSIVE, cs, 0);
> -	}
> -	return 0;
> -}
> -
>  /*
>   * Update partition load balance flag and/or rebuild sched domain
>   *
> @@ -1248,11 +1229,9 @@ static void reset_partition_data(struct cpuset *cs)
>  
>  	lockdep_assert_held(&callback_lock);
>  
> -	if (cpumask_empty(cs->exclusive_cpus)) {
> +	if (cpumask_empty(cs->exclusive_cpus))
>  		cpumask_clear(cs->effective_xcpus);
> -		if (is_cpu_exclusive(cs))
> -			clear_bit(CS_CPU_EXCLUSIVE, &cs->flags);
> -	}
> +
>  	if (!cpumask_and(cs->effective_cpus, parent->effective_cpus, cs->cpus_allowed))
>  		cpumask_copy(cs->effective_cpus, parent->effective_cpus);
>  }
> @@ -2028,19 +2007,6 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
>  	if (!adding && !deleting && (new_prs == old_prs))
>  		return 0;
>  
> -	/*
> -	 * Transitioning between invalid to valid or vice versa may require
> -	 * changing CS_CPU_EXCLUSIVE. In the case of partcmd_update,
> -	 * validate_change() has already been successfully called and
> -	 * CPU lists in cs haven't been updated yet. So defer it to later.
> -	 */
> -	if ((old_prs != new_prs) && (cmd != partcmd_update))  {
> -		int err = update_partition_exclusive_flag(cs, new_prs);
> -
> -		if (err)
> -			return err;
> -	}
> -
>  	/*
>  	 * Change the parent's effective_cpus & effective_xcpus (top cpuset
>  	 * only).
> @@ -2063,9 +2029,6 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
>  
>  	spin_unlock_irq(&callback_lock);
>  
> -	if ((old_prs != new_prs) && (cmd == partcmd_update))
> -		update_partition_exclusive_flag(cs, new_prs);
> -
>  	if (adding || deleting) {
>  		cpuset_update_tasks_cpumask(parent, tmp->addmask);
>  		update_sibling_cpumasks(parent, cs, tmp);
> @@ -2942,10 +2905,6 @@ static int update_prstate(struct cpuset *cs, int new_prs)
>  	if (alloc_tmpmasks(&tmpmask))
>  		return -ENOMEM;
>  
> -	err = update_partition_exclusive_flag(cs, new_prs);
> -	if (err)
> -		goto out;
> -
>  	if (!old_prs) {
>  		/*
>  		 * cpus_allowed and exclusive_cpus cannot be both empty.
> @@ -3009,13 +2968,10 @@ static int update_prstate(struct cpuset *cs, int new_prs)
>  	}
>  out:
>  	/*
> -	 * Make partition invalid & disable CS_CPU_EXCLUSIVE if an error
> -	 * happens.
> +	 * Make partition invalid if an error happens.
>  	 */
> -	if (err) {
> +	if (err)
>  		new_prs = -new_prs;
> -		update_partition_exclusive_flag(cs, new_prs);
> -	}
>  
>  	spin_lock_irq(&callback_lock);
>  	cs->partition_root_state = new_prs;

Reviewed-by: Guopeng Zhang <zhangguopeng@kylinos.cn>

Thanks,
Guopeng

Re: [PATCH-next v2 0/2] cgroup/cpuset: Run SCHED_DEADLINE shrink test on valid partition root only

[Tejun Heo]

> Waiman Long (2):
>   cgroup/cpuset: Run SCHED_DEADLINE shrink test on valid partition root
>     only
>   cgroup/cpuset: Remove CS_CPU_EXCLUSIVE handling code from v2

Applied 1-2 to cgroup/for-7.4.

Thanks.

--
tejun