From: Qiliang Yuan <realwujing@gmail.com>
To: peterz@infradead.org
Cc: longman@redhat.com, cgroups@vger.kernel.org,
akpm@linux-foundation.org, anna-maria@linutronix.de,
boqun.feng@gmail.com, bsegall@google.com,
dietmar.eggemann@arm.com, frederic@kernel.org,
hannes@cmpxchg.org, jackmanb@google.com, jiangshanlai@gmail.com,
joelagnelf@nvidia.com, josh@joshtriplett.org,
juri.lelli@redhat.com, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
mathieu.desnoyers@efficios.com, mgorman@suse.de, mhocko@suse.com,
mingo@kernel.org, mingo@redhat.com, neeraj.upadhyay@kernel.org,
paulmck@kernel.org, qiang.zhang@linux.dev, rcu@vger.kernel.org,
realwujing@gmail.com, rostedt@goodmis.org, shuah@kernel.org,
surenb@google.com, tglx@kernel.org, tj@kernel.org,
urezki@gmail.com, vbabka@suse.cz, vincent.guittot@linaro.org,
vschneid@redhat.com, ziy@nvidia.com
Subject: Re: [PATCH 01/15] sched/isolation: Support dynamic allocation for housekeeping masks
Date: Mon, 30 Mar 2026 19:43:21 +0800 [thread overview]
Message-ID: <20260330114348.102265-1-realwujing@gmail.com> (raw)
In-Reply-To: <20260325135707.GZ3738786@noisy.programming.kicks-ass.net>
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Hi Peter,
On Wed, Mar 25, 2026 at 02:57:07PM +0100, Peter Zijlstra wrote:
> I think I asked this a while ago; why do we have more than one mask?
> What is the actual purpose of being able to separate RCU from Timers?
That's a fair point. For the vast majority of use cases (like NOHZ_FULL),
these masks are indeed identical and should be updated as a single unit.
The original motivation for separation was to allow extreme fine-tuning in
HFT environments—for example, offloading RCU callbacks to keep a core
mostly clean but allowing pinned timers for specific localized
telemetry/monitoring.
However, I acknowledge this adds significant complexity. In V13, I will
unify these into a single "Global Housekeeping Mask" by default to
simplify the configuration space, while keeping the underlying notifier
infrastructure flexible enough for future specialized needs.
next prev parent reply other threads:[~2026-03-30 11:44 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-25 9:09 [PATCH 00/15] Implementation of Dynamic Housekeeping & Enhanced Isolation (DHEI) Qiliang Yuan
2026-03-25 9:09 ` [PATCH 01/15] sched/isolation: Support dynamic allocation for housekeeping masks Qiliang Yuan
2026-03-25 13:57 ` Peter Zijlstra
2026-03-30 11:43 ` Qiliang Yuan [this message]
2026-03-25 9:09 ` [PATCH 02/15] sched/isolation: Introduce housekeeping notifier infrastructure Qiliang Yuan
2026-03-25 13:58 ` Peter Zijlstra
2026-03-30 11:44 ` Qiliang Yuan
2026-03-25 9:09 ` [PATCH 03/15] sched/isolation: Separate housekeeping types in enum hk_type Qiliang Yuan
2026-03-25 13:59 ` Peter Zijlstra
2026-03-30 11:44 ` Qiliang Yuan
2026-03-25 9:09 ` [PATCH 04/15] genirq: Support dynamic migration for managed interrupts Qiliang Yuan
2026-03-25 9:09 ` [PATCH 05/15] rcu: Support runtime NOCB initialization and dynamic offloading Qiliang Yuan
2026-03-25 9:09 ` [PATCH 06/15] sched/core: Dynamically update scheduler domain housekeeping mask Qiliang Yuan
2026-03-25 14:00 ` Peter Zijlstra
2026-03-30 11:45 ` Qiliang Yuan
2026-03-25 9:09 ` [PATCH 07/15] watchdog: Allow runtime toggle of lockup detector affinity Qiliang Yuan
2026-03-25 14:03 ` Peter Zijlstra
2026-03-30 11:45 ` Qiliang Yuan
2026-03-25 9:09 ` [PATCH 08/15] workqueue: Support dynamic housekeeping mask updates Qiliang Yuan
2026-03-25 9:09 ` [PATCH 09/15] mm/compaction: Support dynamic housekeeping mask updates for kcompactd Qiliang Yuan
2026-03-25 9:09 ` [PATCH 10/15] tick/nohz: Transition to dynamic full dynticks state management Qiliang Yuan
2026-03-25 9:09 ` [PATCH 11/15] sched/isolation: Implement SMT-aware isolation and safety guards Qiliang Yuan
2026-03-25 9:09 ` [PATCH 12/15] sched/isolation: Bridge boot-time parameters with dynamic isolation Qiliang Yuan
2026-03-25 9:09 ` [PATCH 13/15] sched/isolation: Implement sysfs interface for dynamic housekeeping Qiliang Yuan
2026-03-25 14:04 ` Peter Zijlstra
2026-03-30 11:46 ` Qiliang Yuan
2026-03-25 9:09 ` [PATCH 14/15] Documentation: isolation: Document DHEI sysfs interfaces Qiliang Yuan
2026-03-25 9:09 ` [PATCH 15/15] selftests: dhei: Add functional tests for dynamic housekeeping Qiliang Yuan
2026-03-25 16:02 ` [PATCH 00/15] Implementation of Dynamic Housekeeping & Enhanced Isolation (DHEI) Tejun Heo
2026-03-30 11:41 ` Qiliang Yuan
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