Re: [PATCH-next v3 11/11] cgroup/cpuset: Integrate compute_partition_effective_cpumask() into compute_effective_cpumask()

[Guopeng Zhang <guopeng.zhang@linux.dev>]

在 2026/10/26 05:44, Waiman Long 写道:
> Update compute_effective_cpumask() to call
> compute_partition_effective_cpumask() directly if the given cpuset is
> a valid remote or local partition root. This simplifies the call sites
> where they are being involved. No functional change is expected.
> 
> Suggested-by: Ridong Chen <ridong.chen@linux.dev>
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
>  kernel/cgroup/cpuset.c | 37 ++++++++++---------------------------
>  1 file changed, 10 insertions(+), 27 deletions(-)
> 
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index f37d929616a6..2598a0e2d667 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -1606,8 +1606,6 @@ static void compute_partition_effective_cpumask(struct cpuset *cs,
>  	struct cpuset *child;
>  	bool populated = partition_is_populated(cs, NULL);
>  
> -	WARN_ON_ONCE(!is_partition_valid(cs));
> -
>  	/*
>  	 * Check child partition roots to see if they should be invalidated
>  	 * when all the effective_cpus will be used up and cs is populated.
> @@ -1668,6 +1666,10 @@ static void compute_effective_cpumask(struct cpumask *new_cpus,
>  {
>  	bool has_cpus;
>  
> +	if (is_remote_partition(cs) ||
> +	    (is_partition_valid(cs) && is_partition_valid(parent)))
> +		return compute_partition_effective_cpumask(cs, new_cpus);
> +
>  	has_cpus = cpumask_and(new_cpus, cs->cpus_allowed, parent->effective_cpus);
>  	if (!has_cpus && is_in_v2_mode())
>  		cpumask_copy(new_cpus, parent->effective_cpus);
> @@ -2268,10 +2270,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp,
>  			remote = (new_prs == old_prs);
>  		}
>  
> -		if (remote || (is_partition_valid(parent) && is_partition_valid(cp)))
> -			compute_partition_effective_cpumask(cp, tmp->new_cpus);
> -		else
> -			compute_effective_cpumask(tmp->new_cpus, cp, parent);
> +		compute_effective_cpumask(tmp->new_cpus, cp, parent);
>  
>  		if (remote)
>  			goto get_css;	/* Ready to update cpuset data */
> @@ -2352,10 +2351,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp,
>  			 */
>  			new_prs = cp->partition_root_state;
>  			if (new_prs != old_prs) {
> -				if (new_prs > 0)
> -					compute_partition_effective_cpumask(cp, tmp->new_cpus);
> -				else
> -					compute_effective_cpumask(tmp->new_cpus, cp, parent);
> +				compute_effective_cpumask(tmp->new_cpus, cp, parent);
>  			}
>  		}
>  
> @@ -3987,7 +3983,6 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp)
>  	static nodemask_t new_mems;
>  	bool cpus_updated;
>  	bool mems_updated;
> -	bool remote;
>  	int partcmd = -1;
>  	struct cpuset *parent;
>  
> @@ -3999,21 +3994,12 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp)
>  	if (!tmp || !cs->partition_root_state)
>  		goto update_tasks;
>  
> -	/*
> -	 * Compute effective_cpus for valid partition root, may invalidate
> -	 * child partition roots if necessary.
> -	 */
> -	remote = is_remote_partition(cs);
> -	if (remote || (is_partition_valid(cs) && is_partition_valid(parent)))
> -		compute_partition_effective_cpumask(cs, &new_cpus);
> -
> -	if (remote && (cpumask_empty(subpartitions_cpus) ||
> -			(cpumask_empty(&new_cpus) &&
> -			 partition_is_populated(cs, NULL)))) {
> +	if (is_remote_partition(cs) && (cpumask_empty(subpartitions_cpus) ||
> +				       (cpumask_empty(&new_cpus) &&
> +					partition_is_populated(cs, NULL)))) {
>  		WRITE_ONCE(cs->prs_err, PERR_HOTPLUG);
>  		remote_partition_disable(cs, tmp);
>  		compute_effective_cpumask(&new_cpus, cs, parent);
> -		remote = false;
>  	}
>  
>  	/*
> @@ -4039,10 +4025,7 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp)
>  
>  	if (partcmd >= 0) {
>  		update_parent_effective_cpumask(cs, partcmd, NULL, tmp);
> -		if (is_partition_valid(cs)) {
> -			compute_partition_effective_cpumask(cs, &new_cpus);
> -			cpuset_force_rebuild();
> -		} else if (partcmd == partcmd_invalidate) {
> +		if (is_partition_valid(cs) || (partcmd == partcmd_invalidate)) {
>  			compute_effective_cpumask(&new_cpus, cs, parent);
>  			cpuset_force_rebuild();
>  		}

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

Thanks,
Guopeng