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From: Martin George <martinus.gpy@gmail.com>
To: alistair23@gmail.com, kbusch@kernel.org, axboe@kernel.dk,
	hch@lst.de,  sagi@grimberg.me, linux-nvme@lists.infradead.org
Cc: linux-kernel@vger.kernel.org,
	Alistair Francis <alistair.francis@wdc.com>
Subject: Re: [PATCH] nvme: Use non zero KATO for persistent discovery connections
Date: Tue, 02 Sep 2025 16:05:19 +0530	[thread overview]
Message-ID: <2841bd1b7910bd0e1b263b393152f2cb13dd3ae3.camel@gmail.com> (raw)
In-Reply-To: <20250902035211.2953174-1-alistair.francis@wdc.com>

On Tue, 2025-09-02 at 13:52 +1000, alistair23@gmail.com wrote:
> From: Alistair Francis <alistair.francis@wdc.com>
> 
> The NVMe Base Specification 2.1 states that:
> 
> """
> A host requests an explicit persistent connection ... by specifying a
> non-zero Keep Alive Timer value in the Connect command.
> """
> 
> As such if we are starting a persistent connection to a discovery
> controller and the KATO is currently 0 we need to update KATO to a
> non
> zero value to avoid continuous timeouts on the target.
> 
> 

When would this ever happen? Won't nvme-cli & nvme/host/fabrics.c in
the kernel ensure a PDC (persistent discovery controller) would always
have the KATO either default set to NVMF_DEF_DISC_TMO (i.e. 30s) or any
positive int value & not zero?

Do you have a test log for the above scenario where the KATO ends up
being zero for a PDC?

-Martin


  parent reply	other threads:[~2025-09-02 12:32 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-02  3:52 [PATCH] nvme: Use non zero KATO for persistent discovery connections alistair23
2025-09-02  8:56 ` Hannes Reinecke
2025-09-02 10:35 ` Martin George [this message]
2025-09-03  0:00   ` Alistair Francis

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