[PATCH] nvmet: allow associating port to a cgroup via configfs

[Michal Koutný]

Hello.

On Thu, Jun 29, 2023 at 06:21:34PM +0300, Ofir Gal <ofir.gal at volumez.com> wrote:
> >>> Currently there is no way to throttle nvme targets with cgroup v2.
> >>
> >> How do you do it with v1?
> With v1 I would add a blkio rule at the cgroup root level. The bio's
> that the nvme target submits aren't associated to a specific cgroup,
> which makes them follow the rules of the cgroup root level.
> 
> V2 doesn't allow to set rules at the root level by design.

I think you want to add a per-nvme port (device?) throttled-bandwidth
attribute (instead of param_associated_cgroup) to control this on the
client (whole host) side -- even without cgroups.
Associating ports with cgroups and then bios with cgroups looks
superfluous.
(But it is understandably tempting because then IO controller's
throttling implementaion may be reused.)


How are the nvmet_bdev_execute_rw() et al functions called? (Only via
kthreads without (uspace) process context? Or can the reqs be traced to
a user space process?)

Thanks,
Michal
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 228 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-nvme/attachments/20230630/2a3d47c8/attachment.sig>