The test_cpuset_prs.sh test script is updated to add new test cases to
test this automatic state transition.
Reported-by: Pierre Gondois <pierre.gondois@xxxxxxx>
Link:
https://lore.kernel.org/lkml/9777f0d2-2fdf-41cb-bd01-19c52939ef42@xxxxxxx
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
kernel/cgroup/cpuset.c | 79 +++++++++++--------
.../selftests/cgroup/test_cpuset_prs.sh | 17 ++--
2 files changed, 59 insertions(+), 37 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 15f399153a2e..93facdab513c 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -1806,17 +1806,28 @@ static int
update_parent_effective_cpumask(struct cpuset *cs, int cmd,
*
* Compute add/delete mask to/from effective_cpus
*
- * addmask = effective_xcpus & ~newmask &
parent->effective_xcpus
- * delmask = newmask & ~cs->effective_xcpus
- * & parent->effective_xcpus
+ * For valid partition:
+ * addmask = exclusive_cpus & ~newmask
+ * & parent->effective_xcpus
+ * delmask = newmask & ~exclusive_cpus
+ * & parent->effective_xcpus
+ *
+ * For invalid partition:
+ * delmask = newmask & parent->effective_xcpus
*/
- cpumask_andnot(tmp->addmask, xcpus, newmask);
- adding = cpumask_and(tmp->addmask, tmp->addmask,
- parent->effective_xcpus);
+ if (is_prs_invalid(old_prs)) {
+ adding = false;
+ deleting = cpumask_and(tmp->delmask,
+ newmask, parent->effective_xcpus);
+ } else {
+ cpumask_andnot(tmp->addmask, xcpus, newmask);
+ adding = cpumask_and(tmp->addmask, tmp->addmask,
+ parent->effective_xcpus);
- cpumask_andnot(tmp->delmask, newmask, xcpus);
- deleting = cpumask_and(tmp->delmask, tmp->delmask,
- parent->effective_xcpus);
+ cpumask_andnot(tmp->delmask, newmask, xcpus);
+ deleting = cpumask_and(tmp->delmask, tmp->delmask,
+ parent->effective_xcpus);
+ }
/*
* Make partition invalid if parent's effective_cpus could
* become empty and there are tasks in the parent.
@@ -1910,9 +1921,11 @@ static int
update_parent_effective_cpumask(struct cpuset *cs, int cmd,
/*
* Transitioning between invalid to valid or vice versa may
require
- * changing CS_CPU_EXCLUSIVE.
+ * 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) {
+ if ((old_prs != new_prs) && (cmd != partcmd_update)) {
int err = update_partition_exclusive(cs, new_prs);
if (err)
@@ -1960,6 +1973,9 @@ 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(cs, new_prs);
+
if (adding || deleting) {
update_tasks_cpumask(parent, tmp->addmask);
update_sibling_cpumasks(parent, cs, tmp);
@@ -2356,8 +2372,9 @@ static int update_cpumask(struct cpuset *cs,
struct cpuset *trialcs,
if (alloc_cpumasks(NULL, &tmp))
return -ENOMEM;
- if (is_partition_valid(cs)) {
- if (cpumask_empty(trialcs->effective_xcpus)) {
+ 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)) {
@@ -2391,13 +2408,16 @@ static int update_cpumask(struct cpuset *cs,
struct cpuset *trialcs,
*/
invalidate = true;
rcu_read_lock();
- cpuset_for_each_child(cp, css, parent)
+ cpuset_for_each_child(cp, css, parent) {
+ struct cpumask *xcpus = fetch_xcpus(trialcs);
+
if (is_partition_valid(cp) &&
- cpumask_intersects(trialcs->effective_xcpus,
cp->effective_xcpus)) {
+ cpumask_intersects(xcpus, cp->effective_xcpus)) {
rcu_read_unlock();
update_parent_effective_cpumask(cp,
partcmd_invalidate, NULL, &tmp);
rcu_read_lock();
}
+ }
rcu_read_unlock();
retval = 0;
}
@@ -2405,18 +2425,24 @@ static int update_cpumask(struct cpuset *cs,
struct cpuset *trialcs,
if (retval < 0)
goto out_free;
- if (is_partition_valid(cs)) {
+ if (is_partition_valid(cs) ||
+ (is_partition_invalid(cs) && !invalidate)) {
+ struct cpumask *xcpus = trialcs->effective_xcpus;
+
+ if (cpumask_empty(xcpus) && is_partition_invalid(cs))
+ xcpus = trialcs->cpus_allowed;
+
/*
* Call remote_cpus_update() to handle valid remote partition
*/
if (is_remote_partition(cs))
- remote_cpus_update(cs, trialcs->effective_xcpus, &tmp);
+ remote_cpus_update(cs, xcpus, &tmp);
else if (invalidate)
update_parent_effective_cpumask(cs, partcmd_invalidate,
NULL, &tmp);
else
update_parent_effective_cpumask(cs, partcmd_update,
- trialcs->effective_xcpus, &tmp);
+ xcpus, &tmp);
} else if (!cpumask_empty(cs->exclusive_cpus)) {
/*
* Use trialcs->effective_cpus as a temp cpumask
@@ -2493,7 +2519,7 @@ static int update_exclusive_cpumask(struct
cpuset *cs, struct cpuset *trialcs,
if (retval)
return retval;
- if (is_partition_valid(cs)) {
+ if (old_prs) {
if (cpumask_empty(trialcs->effective_xcpus)) {
invalidate = true;
cs->prs_err = PERR_INVCPUS;
@@ -2927,19 +2953,10 @@ static int update_prstate(struct cpuset *cs,
int new_prs)
return 0;
/*
- * For a previously invalid partition root with valid partition
root
- * parent, treat it as if it is a "member". Otherwise, reject it as
- * remote partition cannot currently self-recover from an invalid
- * state.
+ * Treat a previously invalid partition root as if it is a
"member".
*/
- if (new_prs && is_prs_invalid(old_prs)) {
- if (is_partition_valid(parent)) {
- old_prs = PRS_MEMBER;
- } else {
- cs->partition_root_state = -new_prs;
- return 0;
- }
- }
+ if (new_prs && is_prs_invalid(old_prs))
+ old_prs = PRS_MEMBER;
if (alloc_cpumasks(NULL, &tmpmask))
return -ENOMEM;
diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh
b/tools/testing/selftests/cgroup/test_cpuset_prs.sh
index 0f4f4a57ae12..243c4c926964 100755
--- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh
+++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh
@@ -318,16 +318,18 @@ TEST_MATRIX=(
