open-iscsi and multiqueue

[Erez Zilber]

Mike,

Can open-iscsi utilize the multiqueue feature
(http://lwn.net/Articles/289137/) in order to improve performance? If
yes, does it require any change in open-iscsi? Did you try to measure
the performance improvement?

Thanks,
Erez

[Mike Christie]

I am not sure about any of the above :) People have been sending
questions about multi queue (there is tx multiqueue like in the link you
provided and recv multiqueue too right) and also DCB/DCBX in private and
at work, and I have only begun to start to try it out.

My initial quess was that we can take advantage of multiqueue without
any changes when using software iscsi. I thought the network layer would
handle things for us like it would any other net traffic that uses the
sendpage/sendmsg interface.

For partial offload like with cxgb3i and bnx2i, I am not sure. They both
use different interfaces into the net driver/card.

[Erez Zilber]

Thanks and another question - I understand that this feature was added
somewhere around 2.6.28. Is it already in RHEL 5.X or is it planned to
be added only in RHEL 6.0?

Thanks,
Erez