Messages in this thread | | | From | Saeed Mahameed <> | Subject | Re: [PATCH net-next 0/4] net/mlx5: Memory optimizations | Date | Thu, 2 Dec 2021 18:55:37 +0000 |
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On Thu, 2021-12-02 at 09:31 -0800, Jakub Kicinski wrote: > On Wed, 1 Dec 2021 10:22:17 +0200 Shay Drory wrote: > > On 11/30/2021 21:39, Jakub Kicinski wrote: > > > On Tue, 30 Nov 2021 17:07:02 +0200 Shay Drory wrote: > > > > - Patch-1 Provides I/O EQ size resource which enables to save > > > > up to 128KB. > > > > - Patch-2 Provides event EQ size resource which enables to > > > > save up to > > > > 512KB. > > > Why is something allocated in host memory a device resource? 🤔 > > > > EQ resides in the host memory. It is RO for host driver, RW by > > device. > > When interrupt is generated EQ entry is placed by device and read > > by driver. > > It indicates about what event occurred such as CQE, async and more. > > I understand that. My point was the resource which is being consumed > here is _host_ memory. Is there precedent for configuring host memory > consumption via devlink resource? >
it's a device resource size nonetheless, devlink resource API makes total sense.
> I'd even question whether this belongs in devlink in the first place. > It is not global device config in any way. If devlink represents the > entire device it's rather strange to have a case where main instance > limits a size of some resource by VFs and other endpoints can still > choose whatever they want. >
This resource is per function instance, we have devlink instance per function, e.g. in the VM, there is a VF devlink instance the VM user can use to control own VF resources. in the PF/Hypervisor, the only devlink representation of the VF will be devlink port function (used for other purposes)
for example:
A tenant can fine-tune a resource size tailored to their needs via the VF's own devlink instance.
An admin can only control or restrict a max size of a resource for a given port function ( the devlink instance that represents the VF in the hypervisor). (note: this patchset is not about that)
> > > Did you analyze if others may need this? > > > > So far no feedback by other vendors. > > The resources are implemented in generic way, if other vendors > > would > > like to implement them. > > Well, I was hoping you'd look around, but maybe that's too much to > ask > of a vendor.
We looked, eq is a common object among many other drivers. and DEVLINK_PARAM_GENERIC_ID_MAX_MACS is already a devlink generic param, and i am sure other vendors have limited macs per VF :) .. so this applies to all vendors even if they don't advertise it.
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