Re: [PATCH RFC 00/12] Implementation of Dynamic Housekeeping & Enhanced Isolation (DHEI)

[Joel Fernandes]

On Fri, Feb 06, 2026 at 02:04:21AM -0500, Qiliang Yuan wrote:
> The Linux kernel provides mechanisms like 'isolcpus' and 'nohz_full' to
> reduce interference for latency-sensitive workloads. However, these are
> locked behind the "Reboot Wall" - they can only be configured via boot
> parameters and require a system restart to change.
> 
> *** THIS IS AN RFC ***
> This series is being submitted as an Request For Comments to discuss the
> architectural changes required to support dynamic reconfiguration of
> housekeeping boundaries. Key points for discussion:
[...]
> This series provides the necessary infrastructure for cloud-native
> orchestrators and high-frequency trading platforms to dynamically
> re-partition CPU resources without incurring the downtime of a reboot.

Could you provide more details of the usecase and hardware / CPU topology? In
which situations does a boot time isolation boundary not work? I think
knowing that will help discuss the need for this.

These systems typically have a lot of cores, and only a few of them need to
be isolated I believe (that's my usecase anyway at my day job).

thanks,

--
Joel Fernandes





> 
> Signed-off-by: Qiliang Yuan <realwujing@xxxxxxxxx>
> ---
> Qiliang Yuan (12):
>       sched/isolation: Remove __init restriction from housekeeping cores
>       sched/isolation: Introduce reconfiguration notifier chain
>       genirq: Implement dynamic migration for Managed IRQs
>       rcu: Sync RCU housekeeping mask on notification
>       sched/core: Dynamic update housekeeping_cpumask(HK_TYPE_DOMAIN)
>       watchdog: Allow runtime toggle of hardlockup detector on CPUs
>       workqueue: Dynamic housekeeping mask update support
>       kcompactd: Add housekeeping notifier for dynamic mask update
>       sched/isolation: Separate housekeeping types and add sysfs interface
>       tick/nohz: Implement dynamic nohz_full state update
>       sched/isolation: Implement SMT sibling auto-isolation and safety check
>       sched/isolation: Bridge isolcpus and support runtime tick offload init
> 
>  include/linux/sched/isolation.h |  40 +++++--
>  include/linux/tick.h            |   2 +-
>  kernel/irq/manage.c             |  52 +++++++++
>  kernel/rcu/tree.c               |  43 +++++++
>  kernel/sched/core.c             |   5 +-
>  kernel/sched/isolation.c        | 252 ++++++++++++++++++++++++++++++++++++++--
>  kernel/sched/sched.h            |   2 +-
>  kernel/sched/topology.c         |  26 +++++
>  kernel/time/tick-sched.c        |  63 +++++++++-
>  kernel/watchdog.c               |  24 ++++
>  kernel/workqueue.c              |  39 +++++++
>  mm/compaction.c                 |  26 +++++
>  12 files changed, 547 insertions(+), 27 deletions(-)
> ---
> base-commit: 1f97d9dcf53649c41c33227b345a36902cbb08ad
> change-id: 20260206-feature-dynamic_isolcpus_dhei-ee46b6e3a477
> 
> Best regards,
> -- 
> Qiliang Yuan <realwujing@xxxxxxxxx>
>