Re: [PATCH v2] block: fix rdma queue mapping

Sagi Grimberg
2018-10-16T08:52:37Z

>> Can we please make forward progress on this?
>>
>> Christoph, Sagi:  it seems you think /proc/irq/$IRP/smp_affinity
>> shouldn't be allowed if drivers support managed affinity. Is that
>> correct?
>>
>> Perhaps that can be codified and be a way forward?  IE: Somehow allow
>> the admin to choose either "managed by the driver/ulps" or "managed by
>> the system admin directly"?
>>
>> Or just use Sagi's patch.  Perhaps a WARN_ONCE() if the affinity looks
>> wonked when set via procfs?  Just thinking out loud...
>
> I think we should take my patch. While ideally we'd like to have
> perfect linear irq based queue mapping, people apparently really like
> to modify devices irq affinity. With this, at least some of the queues
> are assigned according to the device affinity. Its not ideal, but at
> least better than blindly falling to default mapping.
>
> Christoph?
>
> If there is strong resistance to the patch we should at least start
> by falling to the default mapping unconditionally.

Ping?

Would you prefer we fallback to the naive mapping if the device is not
using manged affinity?