Re: [PATCH v3 14/15] nvme: Support atomic writes

From: Christoph Hellwig
Date: Wed Feb 14 2024 - 03:00:51 EST


On Tue, Feb 13, 2024 at 02:21:25PM +0000, John Garry wrote:
>> Please also read through TP4098(a) and look at the MAM field.
>
> It's not public, AFAIK.

Oracle is a member, so you can take a look at it easily. If we need
it for Linux I can also work with the NVMe Board to release it.

> And I don't think a feature which allows us to straddle boundaries is too
> interesting really.

Without MAM=1 NVMe can't support atomic writes larger than
AWUPF/NAWUPF, which is typically set to the indirection table
size. You're leaving a lot of potential unused with that.