[PATCH v2 01/12] sched/isolation: Separate housekeeping types in enum hk_type

Qiliang Yuan
2026-04-13T07:43:35Z

Most kernel noise types (TICK, TIMER, RCU, etc.) are currently aliased
to a single HK_TYPE_KERNEL_NOISE enum value. This prevents fine-grained
runtime isolation control as all masks are forced to be identical.

Un-alias service-specific housekeeping types in enum hk_type. This
separation provides the necessary granularity for DHM subsystems to
subscribe to and maintain independent affinity masks.

Signed-off-by: Qiliang Yuan <realwujing@gmail.com>
---
include/linux/sched/isolation.h | 20 ++++++++------------
kernel/sched/isolation.c | 10 +++++++++-
2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index dc3975ff1b2e1..b9a041247565c 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -17,21 +17,17 @@ enum hk_type {
/* Inverse of boot-time isolcpus=managed_irq argument */
HK_TYPE_MANAGED_IRQ,
/* Inverse of boot-time nohz_full= or isolcpus=nohz arguments */
- HK_TYPE_KERNEL_NOISE,
+ HK_TYPE_TICK,
+ HK_TYPE_TIMER,
+ HK_TYPE_RCU,
+ HK_TYPE_MISC,
+ HK_TYPE_WQ,
+ HK_TYPE_KTHREAD,
HK_TYPE_MAX,
-
- /*
- * The following housekeeping types are only set by the nohz_full
- * boot commandline option. So they can share the same value.
- */
- HK_TYPE_TICK = HK_TYPE_KERNEL_NOISE,
- HK_TYPE_TIMER = HK_TYPE_KERNEL_NOISE,
- HK_TYPE_RCU = HK_TYPE_KERNEL_NOISE,
- HK_TYPE_MISC = HK_TYPE_KERNEL_NOISE,
- HK_TYPE_WQ = HK_TYPE_KERNEL_NOISE,
- HK_TYPE_KTHREAD = HK_TYPE_KERNEL_NOISE
};

+#define HK_TYPE_KERNEL_NOISE HK_TYPE_TICK
+
#ifdef CONFIG_CPU_ISOLATION
DECLARE_STATIC_KEY_FALSE(housekeeping_overridden);
extern int housekeeping_any_cpu(enum hk_type type);
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index ef152d401fe20..e05ed5118e651 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -15,9 +15,17 @@ enum hk_flags {
HK_FLAG_DOMAIN_BOOT = BIT(HK_TYPE_DOMAIN_BOOT),
HK_FLAG_DOMAIN = BIT(HK_TYPE_DOMAIN),
HK_FLAG_MANAGED_IRQ = BIT(HK_TYPE_MANAGED_IRQ),
- HK_FLAG_KERNEL_NOISE = BIT(HK_TYPE_KERNEL_NOISE),
+ HK_FLAG_TICK = BIT(HK_TYPE_TICK),
+ HK_FLAG_TIMER = BIT(HK_TYPE_TIMER),
+ HK_FLAG_RCU = BIT(HK_TYPE_RCU),
+ HK_FLAG_MISC = BIT(HK_TYPE_MISC),
+ HK_FLAG_WQ = BIT(HK_TYPE_WQ),
+ HK_FLAG_KTHREAD = BIT(HK_TYPE_KTHREAD),
};

+#define HK_FLAG_KERNEL_NOISE (HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | \
+ HK_FLAG_MISC | HK_FLAG_WQ | HK_FLAG_KTHREAD)
+
DEFINE_STATIC_KEY_FALSE(housekeeping_overridden);
EXPORT_SYMBOL_GPL(housekeeping_overridden);

--
2.43.0