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cgroup/cpuset: Correct invalid remote parition prs

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When enable a remote partition, I found that:

cd /sys/fs/cgroup/
mkdir test
mkdir test/test1
echo +cpuset > cgroup.subtree_control
echo +cpuset >  test/cgroup.subtree_control
echo 3 > test/test1/cpuset.cpus
echo root > test/test1/cpuset.cpus.partition
cat test/test1/cpuset.cpus.partition
root invalid (Parent is not a partition root)

The parent of a remote partition could not be a root. This is due to the
emtpy effective_xcpus. It would be better to prompt the message "invalid
cpu list in cpuset.cpus.exclusive".

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Chen Ridong 2024-08-20 03:01:24 +00:00 committed by Tejun Heo
parent d1a92d2d6c
commit e55f45b4ba
1 changed files with 16 additions and 12 deletions
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28
kernel/cgroup/cpuset.c
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@ -80,6 +80,7 @@ enum prs_errcode {
PERR_HOTPLUG,
PERR_CPUSEMPTY,
PERR_HKEEPING,
PERR_ACCESS,
};
static const char * const perr_strings[] = {
@ -91,6 +92,7 @@ static const char * const perr_strings[] = {
[PERR_HOTPLUG] = "No cpu available due to hotplug",
[PERR_CPUSEMPTY] = "cpuset.cpus and cpuset.cpus.exclusive are empty",
[PERR_HKEEPING] = "partition config conflicts with housekeeping setup",
[PERR_ACCESS] = "Enable partition not permitted",
};
struct cpuset {
@ -1655,7 +1657,7 @@ static inline bool is_local_partition(struct cpuset *cs)
* @cs: the cpuset to update
* @new_prs: new partition_root_state
* @tmp: temparary masks
* Return: 1 if successful, 0 if error
* Return: 0 if successful, errcode if error
*
* Enable the current cpuset to become a remote partition root taking CPUs
* directly from the top cpuset. cpuset_mutex must be held by the caller.
@ -1669,7 +1671,7 @@ static int remote_partition_enable(struct cpuset *cs, int new_prs,
* The user must have sysadmin privilege.
*/
if (!capable(CAP_SYS_ADMIN))
return 0;
return PERR_ACCESS;
/*
* The requested exclusive_cpus must not be allocated to other
@ -1683,7 +1685,7 @@ static int remote_partition_enable(struct cpuset *cs, int new_prs,
if (cpumask_empty(tmp->new_cpus) ||
cpumask_intersects(tmp->new_cpus, subpartitions_cpus) ||
cpumask_subset(top_cpuset.effective_cpus, tmp->new_cpus))
return 0;
return PERR_INVCPUS;
spin_lock_irq(&callback_lock);
isolcpus_updated = partition_xcpus_add(new_prs, NULL, tmp->new_cpus);
@ -1698,7 +1700,7 @@ static int remote_partition_enable(struct cpuset *cs, int new_prs,
*/
update_tasks_cpumask(&top_cpuset, tmp->new_cpus);
update_sibling_cpumasks(&top_cpuset, NULL, tmp);
return 1;
return 0;
}
/*
@ -3151,9 +3153,6 @@ static int update_prstate(struct cpuset *cs, int new_prs)
goto out;
if (!old_prs) {
enum partition_cmd cmd = (new_prs == PRS_ROOT)
? partcmd_enable : partcmd_enablei;
/*
* cpus_allowed and exclusive_cpus cannot be both empty.
*/
@ -3162,13 +3161,18 @@ static int update_prstate(struct cpuset *cs, int new_prs)
goto out;
}
err = update_parent_effective_cpumask(cs, cmd, NULL, &tmpmask);
/*
* If an attempt to become local partition root fails,
* try to become a remote partition root instead.
* If parent is valid partition, enable local partiion.
* Otherwise, enable a remote partition.
*/
if (err && remote_partition_enable(cs, new_prs, &tmpmask))
err = 0;
if (is_partition_valid(parent)) {
enum partition_cmd cmd = (new_prs == PRS_ROOT)
? partcmd_enable : partcmd_enablei;
err = update_parent_effective_cpumask(cs, cmd, NULL, &tmpmask);
} else {
err = remote_partition_enable(cs, new_prs, &tmpmask);
}
} else if (old_prs && new_prs) {
/*
* A change in load balance state only, no change in cpumasks.