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Date: Tue, 17 Feb 2026 13:13:38 -0700
From: Keith Busch <kbusch@kernel.org>
To: Bart Van Assche <bvanassche@acm.org>
Cc: John Garry <john.g.garry@oracle.com>, lsf-pc@lists.linux-foundation.org,
	linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
	linux-scsi@vger.kernel.org
Subject: Re: [LSF/MM/BPF TOPIC] Native SCSI multipath support
Message-ID: <aZTL8srSowTU81Rz@kbusch-mbp>
References: <69349b51-72c2-47f9-948f-f89843af62e4@oracle.com>
 <049a177d-85d6-4c9d-9a9a-f07391046101@acm.org>
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In-Reply-To: <049a177d-85d6-4c9d-9a9a-f07391046101@acm.org>

On Tue, Feb 17, 2026 at 11:33:12AM -0800, Bart Van Assche wrote:
> More important: what will the performance impact be on SCSI devices that
> do not need multipath support? UFS devices don't need multipath support
> and soon (later this year) will support more than one million IOPS per
> device. Further performance improvements are on the roadmap.

For nvme, we can detect if a device is multipath capable. If not, we
skip the multipath layer altogether so it has no performance impact. I'd
imagine the generic library version would similarly require an opt-in
approach that UFS simply wouldn't subscribe to.