[SPDK] NVMe FUSE

[SPDK] NVMe FUSE

[Shalaka Naik]

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Hello,

This is my first message ever on this mailing list so please let me know if this is not the right place to post a question or of any other protocol violations.
My question is -

Has anyone tried sending 2 FUSED commands as detailed in the NVMe spec using the SPDK kit ?

Thanks,
Shalaka

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Re: [SPDK] NVMe FUSE

[Harris, James R]

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Hi Shalaka,

This is the perfect place to post a question like this!

I’m not aware of anyone who’s tried sending fused commands with SPDK.  Are you looking to do a compare and write fused operation?  Or do you have a vendor-specific fused operation?

For compare and write – there’s no explicit API for this currently but its addition is warranted.  Something like spdk_nvme_ns_cmd_compare_and_write().  You cannot really do spdk_nvme_ns_cmd_compare() and then spdk_nvme_ns_cmd_write() currently – there’s no way to pass a fused indicator through the API (plus you have to update the doorbell for both commands at once).

For a vendor-specific fused operation, you can use the raw interface (spdk_nvme_ctrlr_cmd_io_raw) to build the fused operations, but there’s no way currently to submit both at once so that there’s a single doorbell update.

The idea of separating out command construction from doorbell notification isn’t crazy – I could see an API to send a doorbell notification for a specified I/O queue, and then an I/O queue option to specify whether you want to disable automatic doorbell notifications on command submission.

-Jim


From: SPDK <spdk-bounces(a)lists.01.org> on behalf of "Shalaka Naik (Stellus)" <shalaka.naik(a)stellus.com>
Reply-To: Storage Performance Development Kit <spdk(a)lists.01.org>
Date: Tuesday, April 24, 2018 at 11:35 AM
To: "spdk(a)lists.01.org" <spdk(a)lists.01.org>
Subject: [SPDK] NVMe FUSE

Hello,

This is my first message ever on this mailing list so please let me know if this is not the right place to post a question or of any other protocol violations.
My question is –

Has anyone tried sending 2 FUSED commands as detailed in the NVMe spec using the SPDK kit ?

Thanks,
Shalaka

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