From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Daniel Wagner <wagi@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>, Keith Busch <kbusch@kernel.org>,
Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
"Michael S. Tsirkin" <mst@redhat.com>,
Aaron Tomlin <atomlin@atomlin.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Thomas Gleixner <tglx@linutronix.de>,
Costa Shulyupin <costa.shul@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Valentin Schneider <vschneid@redhat.com>,
Waiman Long <llong@redhat.com>, Ming Lei <ming.lei@redhat.com>,
Frederic Weisbecker <frederic@kernel.org>,
Mel Gorman <mgorman@suse.de>, Hannes Reinecke <hare@suse.de>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
linux-nvme@lists.infradead.org, megaraidlinux.pdl@broadcom.com,
linux-scsi@vger.kernel.org, storagedev@microchip.com,
virtualization@lists.linux.dev,
GR-QLogic-Storage-Upstream@marvell.com
Subject: Re: [PATCH v8 00/12] blk: honor isolcpus configuration
Date: Wed, 25 Mar 2026 18:56:10 +0100 [thread overview]
Message-ID: <20260325175610.eY-VHHPS@linutronix.de> (raw)
In-Reply-To: <20250905-isolcpus-io-queues-v8-0-885984c5daca@kernel.org>
On 2025-09-05 16:59:46 [+0200], Daniel Wagner wrote:
> The main changes in this version are
>
> - merged the mapping algorithm into the existing code
> - dropping a bunch of SCSI drivers update
>
> With the merging of the isolcpus-aware mapping code, there is a change in
> how the resulting CPU–hctx mapping looks for systems with identical CPUs
> (non-hyperthreaded CPUs). My understanding is that it shouldn't matter,
> but the devil is in the details.
…
I have been just made aware of this. It is still not merged so let me
ask the questions before it is too late.
What is purpose of managed_irq? Doesn't this sort of aligns with this?
It was originally introduce to limit the number of nvme interrupts which
can have multiple interrupts but don't need to use all of them. virtio
is using it. Yet I don't see an affect if I use isolcpus=managed_irq,X.
I would expect that it limits the number of used interrupts as intended
by this series. The only affect I see is that once the CPU goes off/on
the assigned CPU mask is restored.
What do I miss?
Sebastian
next prev parent reply other threads:[~2026-03-25 17:56 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-05 14:59 [PATCH v8 00/12] blk: honor isolcpus configuration Daniel Wagner
2025-09-05 14:59 ` [PATCH v8 01/12] scsi: aacraid: use block layer helpers to calculate num of queues Daniel Wagner
2025-09-08 6:06 ` Hannes Reinecke
2025-09-05 14:59 ` [PATCH v8 02/12] lib/group_cpus: remove dead !SMP code Daniel Wagner
2025-09-08 6:06 ` Hannes Reinecke
2025-09-05 14:59 ` [PATCH v8 03/12] lib/group_cpus: Add group_mask_cpus_evenly() Daniel Wagner
2025-09-05 14:59 ` [PATCH v8 04/12] genirq/affinity: Add cpumask to struct irq_affinity Daniel Wagner
2025-09-10 8:22 ` Thomas Gleixner
2025-09-05 14:59 ` [PATCH v8 05/12] blk-mq: add blk_mq_{online|possible}_queue_affinity Daniel Wagner
2025-09-05 14:59 ` [PATCH v8 06/12] nvme-pci: use block layer helpers to constrain queue affinity Daniel Wagner
2025-09-05 14:59 ` [PATCH v8 07/12] scsi: Use " Daniel Wagner
2025-09-08 6:08 ` Hannes Reinecke
2025-09-05 14:59 ` [PATCH v8 08/12] virtio: blk/scsi: use " Daniel Wagner
2025-09-05 14:59 ` [PATCH v8 09/12] isolation: Introduce io_queue isolcpus type Daniel Wagner
2025-09-05 14:59 ` [PATCH v8 10/12] blk-mq: use hk cpus only when isolcpus=io_queue is enabled Daniel Wagner
2025-09-08 6:13 ` Hannes Reinecke
2025-09-08 7:26 ` Daniel Wagner
2025-09-08 7:51 ` Hannes Reinecke
2025-09-08 8:08 ` Daniel Wagner
2025-09-10 8:20 ` Thomas Gleixner
2025-09-12 8:32 ` Daniel Wagner
2025-09-12 14:31 ` Thomas Gleixner
2025-09-08 7:36 ` Daniel Wagner
2025-09-08 13:05 ` Daniel Wagner
2025-09-10 6:05 ` kernel test robot
2025-09-05 14:59 ` [PATCH v8 11/12] blk-mq: prevent offlining hk CPUs with associated online isolated CPUs Daniel Wagner
2025-09-05 14:59 ` [PATCH v8 12/12] docs: add io_queue flag to isolcpus Daniel Wagner
2026-03-25 17:56 ` Sebastian Andrzej Siewior [this message]
2026-03-26 7:42 ` [PATCH v8 00/12] blk: honor isolcpus configuration Sebastian Andrzej Siewior
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