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From: K Prateek Nayak <kprateek.nayak@amd.com>
To: Shrikanth Hegde <sshegde@linux.ibm.com>,
	<linux-kernel@vger.kernel.org>, <linuxppc-dev@lists.ozlabs.org>
Cc: <mingo@redhat.com>, <peterz@infradead.org>,
	<juri.lelli@redhat.com>, <vincent.guittot@linaro.org>,
	<tglx@linutronix.de>, <yury.norov@gmail.com>,
	<maddy@linux.ibm.com>, <srikar@linux.ibm.com>,
	<gregkh@linuxfoundation.org>, <pbonzini@redhat.com>,
	<seanjc@google.com>, <vschneid@redhat.com>, <iii@linux.ibm.com>,
	<huschle@linux.ibm.com>, <rostedt@goodmis.org>,
	<dietmar.eggemann@arm.com>, <christophe.leroy@csgroup.eu>
Subject: Re: [PATCH 09/17] sched/core: Add support for nohz_full CPUs
Date: Mon, 24 Nov 2025 10:06:06 +0530	[thread overview]
Message-ID: <ce4a239b-271c-415f-81d1-ef8360f3fd09@amd.com> (raw)
In-Reply-To: <08ff261e-7ac8-4a1d-bceb-b1bf792171ae@linux.ibm.com>

Hello Shrikanth,

On 11/21/2025 10:10 AM, Shrikanth Hegde wrote:
>> Wouldn't the task be pinned if it is running on a nohz CPU?
>> We don't push out pinned tasks so this seems unnecessary.
>> Am I missing something?
>>
> 
> No. Task will not be pinned if it running on nohz_full unless
> user has done a taskset. They are still part of sched domains.
> 
> Pinning is usually true for isolcpus. You need to explicity set taskset
> for isolcpus since by default you won't go to those CPUs.

TIL! I was under the impression that nohz_full is a superset of isolcpus
but I was clearly mistaken. Thank you for clarifying.

-- 
Thanks and Regards,
Prateek



  reply	other threads:[~2025-11-24  4:36 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-19 12:44 [PATCH 00/17] Paravirt CPUs and push task for less vCPU preemption Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 01/17] sched/docs: Document cpu_paravirt_mask and Paravirt CPU concept Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 02/17] cpumask: Introduce cpu_paravirt_mask Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 03/17] sched/core: Dont allow to use CPU marked as paravirt Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 04/17] sched/debug: Remove unused schedstats Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 05/17] sched/fair: Add paravirt movements for proc sched file Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 06/17] sched/fair: Pass current cpu in select_idle_sibling Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 07/17] sched/fair: Don't consider paravirt CPUs for wakeup and load balance Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 08/17] sched/rt: Don't select paravirt CPU for wakeup and push/pull rt task Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 09/17] sched/core: Add support for nohz_full CPUs Shrikanth Hegde
2025-11-21  3:16   ` K Prateek Nayak
2025-11-21  4:40     ` Shrikanth Hegde
2025-11-24  4:36       ` K Prateek Nayak [this message]
2025-11-19 12:44 ` [PATCH 10/17] sched/core: Push current task from paravirt CPU Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 11/17] sysfs: Add paravirt CPU file Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 12/17] powerpc: method to initialize ec and vp cores Shrikanth Hegde
2025-11-21  8:29   ` kernel test robot
2025-11-21 10:14   ` kernel test robot
2025-11-19 12:44 ` [PATCH 13/17] powerpc: enable/disable paravirt CPUs based on steal time Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 14/17] powerpc: process steal values at fixed intervals Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 15/17] powerpc: add debugfs file for controlling handling on steal values Shrikanth Hegde
2025-11-19 12:44 ` [PATCH 16/17] sysfs: Provide write method for paravirt Shrikanth Hegde
2025-11-24 17:04   ` Greg KH
2025-11-24 17:24     ` Steven Rostedt
2025-11-25  2:49       ` Shrikanth Hegde
2025-11-25 15:52         ` Steven Rostedt
2025-11-25 16:02           ` Konstantin Ryabitsev
2025-11-25 16:08             ` Steven Rostedt
2025-11-19 12:44 ` [PATCH 17/17] sysfs: disable arch handling if paravirt file being written Shrikanth Hegde
2025-11-24 17:05 ` [PATCH 00/17] Paravirt CPUs and push task for less vCPU preemption Greg KH
2025-11-25  2:39   ` Shrikanth Hegde
2025-11-25  7:48     ` Christophe Leroy (CS GROUP)
2025-11-25  8:48       ` Shrikanth Hegde
2025-11-27 10:44 ` Shrikanth Hegde
2025-12-04 13:28 ` Ilya Leoshkevich
2025-12-05  5:30   ` Shrikanth Hegde
2025-12-15 17:39     ` Yury Norov
2025-12-18  5:22       ` Shrikanth Hegde
2025-12-08  4:47 ` K Prateek Nayak
2025-12-08  9:57   ` Shrikanth Hegde
2025-12-08 17:58     ` K Prateek Nayak

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