# Re: \[PATCH net-next 0/9\] ibmvnic: Reuse ltb, rx, tx pools

- From: Rick Lindsley \<hidden\>
- Date: 2021-09-01 01:21:41 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/09/11210632
- Thread: https://ratatoskr.run/netdev/2021/09/11210621/t.md

```text
On 8/31/21 5:08 PM, Sukadev Bhattiprolu wrote:
> It can take a long time to free and reallocate rx and tx pools and long
> term buffer (LTB) during each reset of the VNIC. This is specially true
> when the partition (LPAR) is heavily loaded and going through a Logical
> Partition Migration (LPM). The long drawn reset causes the LPAR to lose
> connectivity for extended periods of time and results in "RMC connection"
> errors and the LPM failing.
>
> What is worse is that during the LPM we could get a failover because
> of the lost connectivity. At that point, the vnic driver releases
> even the resources it has already allocated and starts over.
>
> As long as the resources we have already allocated are valid/applicable,
> we might as well hold on to them while trying to allocate the remaining
> resources. This patch set attempts to reuse the resources previously
> allocated as long as they are valid. It seems to vastly improve the
> time taken for the vnic reset. We have also not seen any RMC connection
> issues during our testing with this patch set.
>
> If the backing devices for a vnic adapter are not "matched" (see "pool
> parameters" in patches 8 and 9) it is possible that we will still free
> all the resources and allocate them. If that becomes a common problem,
> we have to address it separately.

We have spent a good amount of time going over this. Thans for all the work.

Reviewed-by:  Rick Lindsley <redacted>
```