On Wed, Jul 02, 2025 at 06:33:57PM +0200, Daniel Wagner wrote:
> Multiqueue drivers spread I/O queues across all CPUs for optimal
> performance. However, these drivers are not aware of CPU isolation
> requirements and will distribute queues without considering the isolcpus
> configuration.
>
> Introduce a new isolcpus mask that allows users to define which CPUs
> should have I/O queues assigned. This is similar to managed_irq, but
> intended for drivers that do not use the managed IRQ infrastructure
>
> Reviewed-by: Hannes Reinecke <h...@suse.de>
> Signed-off-by: Daniel Wagner <w...@kernel.org>
> ---
> 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
> d8501f4709b583b8a1c91574446382f093bccdb1..6b6ae9c5b2f61a93c649a98ea27482b932627fca
> 100644
> --- a/include/linux/sched/isolation.h
> +++ b/include/linux/sched/isolation.h
> @@ -9,6 +9,7 @@
> enum hk_type {
> HK_TYPE_DOMAIN,
> HK_TYPE_MANAGED_IRQ,
> + HK_TYPE_IO_QUEUE,
> HK_TYPE_KERNEL_NOISE,
> HK_TYPE_MAX,
>
> diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
> index
> 93b038d48900a304a29ecc0c8aa8b7d419ea1397..c8cb0cf2b15a11524be73826f38bb2a0709c449c
> 100644
> --- a/kernel/sched/isolation.c
> +++ b/kernel/sched/isolation.c
> @@ -11,6 +11,7 @@
> enum hk_flags {
> HK_FLAG_DOMAIN = BIT(HK_TYPE_DOMAIN),
> HK_FLAG_MANAGED_IRQ = BIT(HK_TYPE_MANAGED_IRQ),
> + HK_FLAG_IO_QUEUE = BIT(HK_TYPE_IO_QUEUE),
> HK_FLAG_KERNEL_NOISE = BIT(HK_TYPE_KERNEL_NOISE),
> };
>
> @@ -224,6 +225,12 @@ 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.
>
> --
> 2.50.0
>
Reviewed-by: Aaron Tomlin <atom...@atomlin.com>
--
Aaron Tomlin
