Re: [PATCH rdma-next v2 03/11] RDMA/core: Preserve restrack resource ID on reinsertion

[Patrisious Haddad <phaddad@nvidia.com>]

On 4/7/2026 1:23 AM, Jason Gunthorpe wrote:
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> On Mon, Apr 06, 2026 at 12:11:14PM +0300, Edward Srouji wrote:
>> From: Patrisious Haddad <phaddad@nvidia.com>
>>
>> rdma_restrack_add() currently always allocates a new ID via
>> xa_alloc_cyclic(), regardless of whether res->id is already set.
>> This change makes sure that the object’s ID remains the same across
>> removal and reinsertion to restrack.
> It would be better to somehow pre-delete it so it is still in the
> xarray but somehow blocked and then allow un pre-deleting. del/add
> pairs are not a good design.
Usually del/add pairs not good due to re-addition possibility of failure 
, here that cant happen ... so any reason why it is still considered bad ?

The problem with marking as deletion here is that it is not only the 
xarray that is being done at the delete operation (there is restrack_put 
and wait_for_completion inside the restrack del to sync with other 
threads that are ongoing).
I don't really see how to pre-delete it correctly without actually 
deleting in this case.

     - Patrisious
>
> Jason