From: Guopeng Zhang <[email protected]>
isolated_cpus tracks CPUs isolated with isolcpus= as well as CPUs in
isolated cpuset partitions. When an isolated partition is released,
isolated_cpus_update() removes its whole CPU mask. This also clears CPUs
which were already isolated at boot.
Update isolated_cpus one CPU at a time and keep CPUs outside the
boot-time domain housekeeping mask isolated.
Fixes: c188f33c864e ("cgroup/cpuset: Account for boot time isolated CPUs")
Signed-off-by: Guopeng Zhang <[email protected]>
---
kernel/cgroup/cpuset.c | 39 +++++++++++++++++++++++++++++----------
1 file changed, 29 insertions(+), 10 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index d100634fa12b..2538faac9aba 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -1259,6 +1259,28 @@ static void reset_partition_data(struct cpuset *cs)
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
}
+/* Return true if isolated_cpus changes. */
+static bool isolated_cpu_update(int new_prs, int cpu)
+{
+ lockdep_assert_held(&callback_lock);
+ lockdep_assert_held(&cpuset_mutex);
+
+ if (new_prs == PRS_ISOLATED) {
+ if (cpumask_test_cpu(cpu, isolated_cpus))
+ return false;
+ cpumask_set_cpu(cpu, isolated_cpus);
+ return true;
+ }
+
+ /* CPUs isolated at boot must remain isolated. */
+ if (!cpumask_test_cpu(cpu,
+ housekeeping_cpumask(HK_TYPE_DOMAIN_BOOT)) ||
+ !cpumask_test_cpu(cpu, isolated_cpus))
+ return false;
+ cpumask_clear_cpu(cpu, isolated_cpus);
+ return true;
+}
+
/*
* isolated_cpus_update - Update the isolated_cpus mask
* @old_prs: old partition_root_state
@@ -1267,19 +1289,16 @@ static void reset_partition_data(struct cpuset *cs)
*/
static void isolated_cpus_update(int old_prs, int new_prs, struct cpumask
*xcpus)
{
+ bool updated = false;
+ int cpu;
+
WARN_ON_ONCE(old_prs == new_prs);
lockdep_assert_held(&callback_lock);
lockdep_assert_held(&cpuset_mutex);
- if (new_prs == PRS_ISOLATED) {
- if (cpumask_subset(xcpus, isolated_cpus))
- return;
- cpumask_or(isolated_cpus, isolated_cpus, xcpus);
- } else {
- if (!cpumask_intersects(xcpus, isolated_cpus))
- return;
- cpumask_andnot(isolated_cpus, isolated_cpus, xcpus);
- }
- update_housekeeping = true;
+ for_each_cpu(cpu, xcpus)
+ updated |= isolated_cpu_update(new_prs, cpu);
+ if (updated)
+ update_housekeeping = true;
}
/*
--
2.43.0
