[PATCH 1/3] sched/isolation: Add io_queue housekeeping option

[Daniel Wagner]

Drivers such as nvme-pci are spreading the IO queues on all CPUs. This
is not necessary an invalid setup when using isolcpus but there are also
users of isolcpus which do not want to have any IO workload on the
isolated CPUs.

Add a new house keeping type so the infrastructure code and drivers are
able to distinguish between the two setups.

Signed-off-by: Daniel Wagner <dwagner at suse.de>
---
 include/linux/sched/isolation.h | 1 +
 kernel/sched/isolation.c        | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index 2b461129d1fa..fe751d704e99 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -16,6 +16,7 @@ enum hk_type {
 	HK_TYPE_WQ,
 	HK_TYPE_MANAGED_IRQ,
 	HK_TYPE_KTHREAD,
+	HK_TYPE_IO_QUEUE,
 	HK_TYPE_MAX
 };
 
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 5891e715f00d..91d7a434330c 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -18,6 +18,7 @@ enum hk_flags {
 	HK_FLAG_WQ		= BIT(HK_TYPE_WQ),
 	HK_FLAG_MANAGED_IRQ	= BIT(HK_TYPE_MANAGED_IRQ),
 	HK_FLAG_KTHREAD		= BIT(HK_TYPE_KTHREAD),
+	HK_FLAG_IO_QUEUE	= BIT(HK_TYPE_IO_QUEUE),
 };
 
 DEFINE_STATIC_KEY_FALSE(housekeeping_overridden);
@@ -228,6 +229,12 @@ static int __init housekeeping_isolcpus_setup(char *str)
 			continue;
 		}
 
+		if (!strncmp(str, "io_queue,", 9)) {
+			str += 9;
+			flags |= HK_FLAG_IO_QUEUE;
+			continue;
+		}
+
 		/*
 		 * Skip unknown sub-parameter and validate that it is not
 		 * containing an invalid character.

-- 
2.45.2