From: Chen Ridong <chenridong@huawei.com>
This patch adds cpus_excl_conflict() and mems_excl_conflict() helper
functions to improve code readability and maintainability. The exclusive
conflict checking follows these rules:
1. If either cpuset has the 'exclusive' flag set, their user_xcpus must
not have any overlap.
2. If both cpusets are non-exclusive, their 'cpuset.cpus.exclusive' values
must not intersect.
3. The 'cpuset.cpus' of one cpuset must not form a subset of another
cpuset's 'cpuset.cpus.exclusive'.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
---
kernel/cgroup/cpuset.c | 74 +++++++++++++++++++++++++-----------------
1 file changed, 44 insertions(+), 30 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 55674a5ad2f9..389dfd5be6c8 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -582,6 +582,47 @@ static inline bool cpusets_are_exclusive(struct cpuset *cs1, struct cpuset *cs2)
return true;
}
+/**
+ * cpus_excl_conflict - Check if two cpusets have exclusive CPU conflicts
+ * @cs1: first cpuset to check
+ * @cs2: second cpuset to check
+ *
+ * Returns: true if CPU exclusivity conflict exists, false otherwise
+ *
+ * Conflict detection rules:
+ * 1. If either cpuset is CPU exclusive, they must be mutually exclusive
+ * 2. exclusive_cpus masks cannot intersect between cpusets
+ * 3. The allowed CPUs of one cpuset cannot be a subset of another's exclusive CPUs
+ */
+static inline bool cpus_excl_conflict(struct cpuset *cs1, struct cpuset *cs2)
+{
+ /* If either cpuset is exclusive, check if they are mutually exclusive */
+ if (is_cpu_exclusive(cs1) || is_cpu_exclusive(cs2))
+ return !cpusets_are_exclusive(cs1, cs2);
+
+ /* Exclusive_cpus cannot intersect */
+ if (cpumask_intersects(cs1->exclusive_cpus, cs2->exclusive_cpus))
+ return true;
+
+ /* The cpus_allowed of one cpuset cannot be a subset of another cpuset's exclusive_cpus */
+ if (!cpumask_empty(cs1->cpus_allowed) &&
+ cpumask_subset(cs1->cpus_allowed, cs2->exclusive_cpus))
+ return true;
+
+ if (!cpumask_empty(cs2->cpus_allowed) &&
+ cpumask_subset(cs2->cpus_allowed, cs1->exclusive_cpus))
+ return true;
+
+ return false;
+}
+
+static inline bool mems_excl_conflict(struct cpuset *cs1, struct cpuset *cs2)
+{
+ if ((is_mem_exclusive(cs1) || is_mem_exclusive(cs2)))
+ return nodes_intersects(cs1->mems_allowed, cs2->mems_allowed);
+ return false;
+}
+
/*
* validate_change() - Used to validate that any proposed cpuset change
* follows the structural rules for cpusets.
@@ -663,38 +704,11 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
*/
ret = -EINVAL;
cpuset_for_each_child(c, css, par) {
- bool txset, cxset; /* Are exclusive_cpus set? */
-
if (c == cur)
continue;
-
- txset = !cpumask_empty(trial->exclusive_cpus);
- cxset = !cpumask_empty(c->exclusive_cpus);
- if (is_cpu_exclusive(trial) || is_cpu_exclusive(c) ||
- (txset && cxset)) {
- if (!cpusets_are_exclusive(trial, c))
- goto out;
- } else if (txset || cxset) {
- struct cpumask *xcpus, *acpus;
-
- /*
- * When just one of the exclusive_cpus's is set,
- * cpus_allowed of the other cpuset, if set, cannot be
- * a subset of it or none of those CPUs will be
- * available if these exclusive CPUs are activated.
- */
- if (txset) {
- xcpus = trial->exclusive_cpus;
- acpus = c->cpus_allowed;
- } else {
- xcpus = c->exclusive_cpus;
- acpus = trial->cpus_allowed;
- }
- if (!cpumask_empty(acpus) && cpumask_subset(acpus, xcpus))
- goto out;
- }
- if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) &&
- nodes_intersects(trial->mems_allowed, c->mems_allowed))
+ if (cpus_excl_conflict(trial, c))
+ goto out;
+ if (mems_excl_conflict(trial, c))
goto out;
}
--
2.34.1