On 9/8/25 11:32 PM, Chen Ridong wrote:
> From: Chen Ridong <chenridong@huawei.com>
>
> Refactor the validate_partition function to handle cpuset partition
> validation when modifying cpuset.cpus. This refactoring also makes the
> function reusable for handling cpuset.cpus.exclusive updates in subsequent
> patches.
>
> Signed-off-by: Chen Ridong <chenridong@huawei.com>
> ---
> kernel/cgroup/cpuset.c | 48 +++++++++++++++++++++++++++++++-----------
> 1 file changed, 36 insertions(+), 12 deletions(-)
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 389dfd5be6c8..770b33e30576 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -2386,6 +2386,37 @@ static int parse_cpuset_cpulist(const char *buf, struct cpumask *out_mask)
> return 0;
> }
>
> +/**
> + * validate_partition - Validate a cpuset partition configuration
> + * @cs: The cpuset to validate
> + * @trialcs: The trial cpuset containing proposed configuration changes
> + *
> + * If any validation check fails, the appropriate error code is set in the
> + * cpuset's prs_err field.
> + *
> + * Return: PRS error code (0 if valid, non-zero error code if invalid)
> + */
> +static enum prs_errcode validate_partition(struct cpuset *cs, struct cpuset *trialcs)
> +{
> + struct cpuset *parent = parent_cs(cs);
> +
> + if (cs_is_member(trialcs))
> + return PERR_NONE;
> +
> + if (cpumask_empty(trialcs->effective_xcpus))
> + return PERR_INVCPUS;
> +
> + if (prstate_housekeeping_conflict(trialcs->partition_root_state,
> + trialcs->effective_xcpus))
> + return PERR_HKEEPING;
> +
> + if (tasks_nocpu_error(parent, cs, trialcs->effective_xcpus))
> + return PERR_NOCPUS;
> +
> + return PERR_NONE;
> +}
> +
> +
> /**
> * update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it
> * @cs: the cpuset to consider
> @@ -2401,6 +2432,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
> bool invalidate = false;
> bool force = false;
> int old_prs = cs->partition_root_state;
> + enum prs_errcode prs_err;
>
> retval = parse_cpuset_cpulist(buf, trialcs->cpus_allowed);
> if (retval < 0)
> @@ -2415,18 +2447,10 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
>
> compute_trialcs_excpus(trialcs, cs);
>
> - if (old_prs) {
> - if (is_partition_valid(cs) &&
> - cpumask_empty(trialcs->effective_xcpus)) {
> - invalidate = true;
> - cs->prs_err = PERR_INVCPUS;
> - } else if (prstate_housekeeping_conflict(old_prs, trialcs->effective_xcpus)) {
> - invalidate = true;
> - cs->prs_err = PERR_HKEEPING;
> - } else if (tasks_nocpu_error(parent, cs, trialcs->effective_xcpus)) {
> - invalidate = true;
> - cs->prs_err = PERR_NOCPUS;
> - }
> + prs_err = validate_partition(cs, trialcs);
> + if (prs_err) {
> + invalidate = true;
> + cs->prs_err = prs_err;
> }
>
> /*
Reviewed-by: Waiman Long <longman@redhat.com>