From: Waiman Long <longman@redhat.com>
To: "Tejun Heo" <tj@kernel.org>,
"Johannes Weiner" <hannes@cmpxchg.org>,
"Michal Koutný" <mkoutny@suse.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Frederic Weisbecker" <frederic@kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
"Neeraj Upadhyay" <neeraj.upadhyay@kernel.org>,
"Joel Fernandes" <joelagnelf@nvidia.com>,
"Josh Triplett" <josh@joshtriplett.org>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Uladzislau Rezki" <urezki@gmail.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Mathieu Desnoyers" <mathieu.desnoyers@efficios.com>,
"Lai Jiangshan" <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang@linux.dev>,
"Anna-Maria Behnsen" <anna-maria@linutronix.de>,
"Ingo Molnar" <mingo@kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Peter Zijlstra" <peterz@infradead.org>,
"Juri Lelli" <juri.lelli@redhat.com>,
"Vincent Guittot" <vincent.guittot@linaro.org>,
"Dietmar Eggemann" <dietmar.eggemann@arm.com>,
"Ben Segall" <bsegall@google.com>, "Mel Gorman" <mgorman@suse.de>,
"Valentin Schneider" <vschneid@redhat.com>,
"Shuah Khan" <shuah@kernel.org>
Cc: cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, rcu@vger.kernel.org,
linux-kselftest@vger.kernel.org, Phil Auld <pauld@redhat.com>,
Costa Shulyupin <costa.shul@redhat.com>,
Gabriele Monaco <gmonaco@redhat.com>,
Cestmir Kalina <ckalina@redhat.com>,
Waiman Long <longman@redhat.com>
Subject: [RFC PATCH 16/18] cgroup/cpuset: Don't set have_boot_nohz_full without any boot time nohz_full CPU
Date: Fri, 8 Aug 2025 11:19:59 -0400 [thread overview]
Message-ID: <20250808152001.20245-7-longman@redhat.com> (raw)
In-Reply-To: <20250808151053.19777-1-longman@redhat.com>
As HK_TYPE_KERNEL_NOISE bit can now be set without any nohz_full CPU
specified at boot time, don't set have_boot_nohz_full in this case.
Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/cgroup/cpuset.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index de9cb92a0fc7..489708f4e096 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -3871,7 +3871,12 @@ int __init cpuset_init(void)
BUG_ON(!alloc_cpumask_var(&cpus_attach, GFP_KERNEL));
- have_boot_nohz_full = housekeeping_enabled(HK_TYPE_KERNEL_NOISE);
+ /*
+ * HK_TYPE_KERNEL_NOISE bit can be set without any nohz_full CPU
+ */
+ have_boot_nohz_full = housekeeping_enabled(HK_TYPE_KERNEL_NOISE) &&
+ !cpumask_equal(cpu_possible_mask,
+ housekeeping_cpumask(HK_TYPE_KERNEL_NOISE));
have_boot_isolcpus = housekeeping_enabled(HK_TYPE_DOMAIN);
if (have_boot_nohz_full) {
BUG_ON(!alloc_cpumask_var(&boot_nohz_full_hk_cpus, GFP_KERNEL));
--
2.50.0
next prev parent reply other threads:[~2025-08-08 15:21 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-08 15:10 [RFC PATCH 00/18] cgroup/cpuset: Enable runtime modification of Waiman Long
2025-08-08 15:10 ` [RFC PATCH 01/18] sched/isolation: Enable runtime update of housekeeping cpumasks Waiman Long
2025-08-08 15:10 ` [RFC PATCH 02/18] sched/isolation: Call sched_tick_offload_init() when HK_FLAG_KERNEL_NOISE is first set Waiman Long
2025-08-08 15:10 ` [RFC PATCH 03/18] sched/isolation: Use RCU to delay successive housekeeping cpumask updates Waiman Long
2025-08-08 15:10 ` [RFC PATCH 04/18] sched/isolation: Add a debugfs file to dump housekeeping cpumasks Waiman Long
2025-08-08 15:10 ` [RFC PATCH 05/18] cpu/hotplug: Add a new cpuhp_offline_cb() API Waiman Long
2025-08-08 15:10 ` [RFC PATCH 06/18] cgroup/cpuset: Introduce a new top level isolcpus_update_mutex Waiman Long
2025-08-08 15:10 ` [RFC PATCH 07/18] cgroup/cpuset: Allow overwriting HK_TYPE_DOMAIN housekeeping cpumask Waiman Long
2025-08-08 15:10 ` [RFC PATCH 08/18] cgroup/cpuset: Use CPU hotplug to enable runtime nohz_full modification Waiman Long
2025-08-08 15:10 ` [RFC PATCH 09/18] cgroup/cpuset: Revert "Include isolated cpuset CPUs in cpu_is_isolated() check" Waiman Long
2025-08-08 15:19 ` [RFC PATCH 10/18] sched/core: Ignore DL BW deactivation error if in cpuhp_offline_cb_mode Waiman Long
2025-08-08 15:19 ` [RFC PATCH 11/18] tick/nohz: Make nohz_full parameter optional Waiman Long
2025-08-08 15:19 ` [RFC PATCH 12/18] tick/nohz: Introduce tick_nohz_full_update_cpus() to update tick_nohz_full_mask Waiman Long
2025-08-08 15:19 ` [RFC PATCH 13/18] tick/nohz: Allow runtime changes in full dynticks CPUs Waiman Long
2025-08-08 15:19 ` [RFC PATCH 14/18] tick: Pass timer tick job to an online HK CPU in tick_cpu_dying() Waiman Long
2025-08-08 15:19 ` [RFC PATCH 15/18] cgroup/cpuset: Enable RCU NO-CB CPU offloading of newly isolated CPUs Waiman Long
2025-08-08 15:19 ` Waiman Long [this message]
2025-08-08 15:20 ` [RFC PATCH 17/18] cgroup/cpuset: Documentation updates & don't use CPU 0 for isolated partition Waiman Long
2025-08-08 15:20 ` [RFC PATCH 18/18] cgroup/cpuset: Add pr_debug() statements for cpuhp_offline_cb() call Waiman Long
2025-08-08 15:50 ` [RFC PATCH 00/18] cgroup/cpuset: Enable runtime modification of Frederic Weisbecker
2025-08-08 16:27 ` Waiman Long
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250808152001.20245-7-longman@redhat.com \
--to=longman@redhat.com \
--cc=anna-maria@linutronix.de \
--cc=boqun.feng@gmail.com \
--cc=bsegall@google.com \
--cc=cgroups@vger.kernel.org \
--cc=ckalina@redhat.com \
--cc=corbet@lwn.net \
--cc=costa.shul@redhat.com \
--cc=dietmar.eggemann@arm.com \
--cc=frederic@kernel.org \
--cc=gmonaco@redhat.com \
--cc=hannes@cmpxchg.org \
--cc=jiangshanlai@gmail.com \
--cc=joelagnelf@nvidia.com \
--cc=josh@joshtriplett.org \
--cc=juri.lelli@redhat.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mgorman@suse.de \
--cc=mingo@kernel.org \
--cc=mkoutny@suse.com \
--cc=neeraj.upadhyay@kernel.org \
--cc=pauld@redhat.com \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=qiang.zhang@linux.dev \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=shuah@kernel.org \
--cc=tglx@linutronix.de \
--cc=tj@kernel.org \
--cc=urezki@gmail.com \
--cc=vincent.guittot@linaro.org \
--cc=vschneid@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).