From: Christoph Hellwig <hch@lst.de>
To: Caleb Sander Mateos <csander@purestorage.com>
Cc: Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@kernel.dk>,
Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
Chaitanya Kulkarni <kch@nvidia.com>,
linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/6] nvmet: report NPDGL and NPDAL
Date: Fri, 20 Feb 2026 17:11:55 +0100 [thread overview]
Message-ID: <20260220161155.GG15071@lst.de> (raw)
In-Reply-To: <20260220032809.758089-7-csander@purestorage.com>
On Thu, Feb 19, 2026 at 08:28:09PM -0700, Caleb Sander Mateos wrote:
> A block device with a very large discard_granularity queue limit may not
> be able to report it in the 16-bit NPDG and NPDA fields in the Identify
> Namespace data structure. For this reason, version 2.1 of the NVMe specs
> added 32-bit fields NPDGL and NPDAL to the NVM Command Set Specific
> Identify Namespace structure. So report the discard_granularity there
> too and set OPTPERF to 11b to indicate those fields are supported.
From a pure mechanics point of view this looks fine. I'll not that
actually aligning the discard to these granularities probably won't
really work for most file systems, though.
next prev parent reply other threads:[~2026-02-20 16:11 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-20 3:28 [PATCH 0/6] nvme: improve discard_granularity spec compliance Caleb Sander Mateos
2026-02-20 3:28 ` [PATCH 1/6] nvme: add preferred I/O size fields to struct nvme_id_ns_nvm Caleb Sander Mateos
2026-02-20 16:06 ` Christoph Hellwig
2026-02-21 2:55 ` Caleb Sander Mateos
2026-02-23 13:24 ` Christoph Hellwig
2026-02-20 3:28 ` [PATCH 2/6] nvme: update nvme_id_ns OPTPERF constants Caleb Sander Mateos
2026-02-20 16:07 ` Christoph Hellwig
2026-02-20 16:17 ` Caleb Sander Mateos
2026-02-20 16:20 ` Christoph Hellwig
2026-02-20 3:28 ` [PATCH 3/6] nvme: always issue I/O Command Set specific Identify Namespace Caleb Sander Mateos
2026-02-20 16:08 ` Christoph Hellwig
2026-02-20 3:28 ` [PATCH 4/6] nvme: set discard_granularity from NPDG/NPDA Caleb Sander Mateos
2026-02-20 16:10 ` Christoph Hellwig
2026-02-20 3:28 ` [PATCH 5/6] nvmet: use NVME_NS_FEAT_OPTPERF_SHIFT Caleb Sander Mateos
2026-02-20 16:10 ` Christoph Hellwig
2026-02-20 3:28 ` [PATCH 6/6] nvmet: report NPDGL and NPDAL Caleb Sander Mateos
2026-02-20 16:11 ` Christoph Hellwig [this message]
2026-02-20 16:05 ` [PATCH 0/6] nvme: improve discard_granularity spec compliance Christoph Hellwig
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