From: Waiman Long <llong@redhat.com>
To: Frederic Weisbecker <frederic@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Cc: Tejun Heo <tj@kernel.org>, Phil Auld <pauld@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Danilo Krummrich <dakr@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Michal Koutny <mkoutny@suse.com>,
netdev@vger.kernel.org, Roman Gushchin <roman.gushchin@linux.dev>,
linux-block@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Eric Dumazet <edumazet@google.com>,
Michal Hocko <mhocko@suse.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Ingo Molnar <mingo@redhat.com>,
Chen Ridong <chenridong@huawei.com>,
cgroups@vger.kernel.org, linux-pci@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"David S . Miller" <davem@davemloft.net>,
Vlastimil Babka <vbabka@suse.cz>,
Marco Crivellari <marco.crivellari@suse.com>,
Andrew Morton <akpm@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Simon Horman <horms@kernel.org>,
Shakeel Butt <shakeel.butt@linux.dev>,
linux-mm@kvack.org, Jakub Kicinski <kuba@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Gabriele Monaco <gmonaco@redhat.com>,
Muchun Song <muchun.song@linux.dev>,
Will Deacon <will@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Chen Ridong <chenridong@huaweicloud.com>
Subject: Re: [PATCH 00/33 v6] cpuset/isolation: Honour kthreads preferred affinity
Date: Mon, 12 Jan 2026 13:23:40 -0500 [thread overview]
Message-ID: <437ccd7a-e839-4b40-840c-7c40d22f8166@redhat.com> (raw)
In-Reply-To: <20260101221359.22298-1-frederic@kernel.org>
On 1/1/26 5:13 PM, Frederic Weisbecker wrote:
> Hi,
>
> The kthread code was enhanced lately to provide an infrastructure which
> manages the preferred affinity of unbound kthreads (node or custom
> cpumask) against housekeeping constraints and CPU hotplug events.
>
> One crucial missing piece is cpuset: when an isolated partition is
> created, deleted, or its CPUs updated, all the unbound kthreads in the
> top cpuset are affine to _all_ the non-isolated CPUs, possibly breaking
> their preferred affinity along the way
>
> Solve this with performing the kthreads affinity update from cpuset to
> the kthreads consolidated relevant code instead so that preferred
> affinities are honoured.
>
> The dispatch of the new cpumasks to workqueues and kthreads is performed
> by housekeeping, as per the nice Tejun's suggestion.
>
> As a welcome side effect, HK_TYPE_DOMAIN then integrates both the set
> from isolcpus= and cpuset isolated partitions. Housekeeping cpumasks are
> now modifyable with specific synchronization. A big step toward making
> nohz_full= also mutable through cpuset in the future.
>
> Changes since v5:
>
> * Add more tags
>
> * Fix leaked destroy_work_on_stack() (Zhang Qiao, Waiman Long)
>
> * Comment schedule_drain_work() synchronization requirement (Tejun)
>
> * s/Revert of/Inverse of (Waiman Long)
>
> * Remove housekeeping_update() needless (for now) parameter (Chen Ridong)
>
> * Don't propagate housekeeping_update() failures beyond allocations (Waiman Long)
>
> * Whitespace cleanup (Waiman Long)
>
>
> git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
> kthread/core-v6
>
> HEAD: 811e87ca8a0a1e54eb5f23e71896cb97436cccdc
>
> Happy new year,
> Frederic
I don't see any major issue with this v6 version. There may be some
minor issues that can be cleaned up later. Now the issue is which tree
should this series go to as it touches a number of different subsystems
with different maintainers.
Cheers,
Longman
next prev parent reply other threads:[~2026-01-12 18:24 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-01 22:13 Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 01/33] PCI: Prepare to protect against concurrent isolated cpuset change Frederic Weisbecker
2026-01-07 19:05 ` Bjorn Helgaas
2026-01-07 23:30 ` Frederic Weisbecker
2026-01-07 23:39 ` Bjorn Helgaas
2026-01-08 8:43 ` Jinhui Guo
2026-01-01 22:13 ` [PATCH 02/33] cpu: Revert "cpu/hotplug: Prevent self deadlock on CPU hot-unplug" Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 03/33] memcg: Prepare to protect against concurrent isolated cpuset change Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 04/33] mm: vmstat: " Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 05/33] sched/isolation: Save boot defined domain flags Frederic Weisbecker
2026-01-12 18:03 ` Waiman Long
2026-01-01 22:13 ` [PATCH 06/33] cpuset: Convert boot_hk_cpus to use HK_TYPE_DOMAIN_BOOT Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 07/33] driver core: cpu: Convert /sys/devices/system/cpu/isolated " Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 08/33] net: Keep ignoring isolated cpuset change Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 09/33] block: Protect against concurrent " Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 10/33] timers/migration: Prevent from lockdep false positive warning Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 11/33] cpu: Provide lockdep check for CPU hotplug lock write-held Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 12/33] cpuset: Provide lockdep check for cpuset lock held Frederic Weisbecker
2026-01-12 1:43 ` Waiman Long
2026-01-12 17:53 ` Waiman Long
2026-01-01 22:13 ` [PATCH 13/33] sched/isolation: Convert housekeeping cpumasks to rcu pointers Frederic Weisbecker
2026-01-07 11:56 ` Simon Horman
2026-01-12 2:45 ` Waiman Long
2026-01-12 21:34 ` Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 14/33] cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 15/33] sched/isolation: Flush memcg workqueues on cpuset isolated partition change Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 16/33] sched/isolation: Flush vmstat " Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 17/33] PCI: Flush PCI probe workqueue " Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 18/33] cpuset: Propagate cpuset isolation update to workqueue through housekeeping Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 19/33] cpuset: Propagate cpuset isolation update to timers " Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 20/33] timers/migration: Remove superfluous cpuset isolation test Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 21/33] cpuset: Remove cpuset_cpu_is_isolated() Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 22/33] sched/isolation: Remove HK_TYPE_TICK test from cpu_is_isolated() Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 23/33] PCI: Remove superfluous HK_TYPE_WQ check Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 24/33] kthread: Refine naming of affinity related fields Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 25/33] kthread: Include unbound kthreads in the managed affinity list Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 26/33] kthread: Include kthreadd to " Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 27/33] kthread: Rely on HK_TYPE_DOMAIN for preferred affinity management Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 28/33] sched: Switch the fallback task allowed cpumask to HK_TYPE_DOMAIN Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 29/33] sched/arm64: Move fallback task " Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 30/33] kthread: Honour kthreads preferred affinity after cpuset changes Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 31/33] kthread: Comment on the purpose and placement of kthread_affine_node() call Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 32/33] kthread: Document kthread_affine_preferred() Frederic Weisbecker
2026-01-01 22:13 ` [PATCH 33/33] doc: Add housekeeping documentation Frederic Weisbecker
2026-01-12 18:23 ` Waiman Long [this message]
2026-01-12 22:09 ` [PATCH 00/33 v6] cpuset/isolation: Honour kthreads preferred affinity Frederic Weisbecker
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