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 <[email protected]> > --- > 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 <[email protected]> >
