On 6/9/2015 12:12 PM, Zhu Lingshan wrote:
Hi,
Hi Zhu,
I remember that multiqueue for LIO is done, and need to implement
multiqueue to open-iscsi, the initiator.
I got some information about multiqueue of LIO from emails and git
logs. I think maybe I can do some contribution on initiator side to make
them work together. Would you please send me some documents of LIO
multiqueue? Docs of LIO itself are also welcome, I need to study a lot
of the design and arch.
There isn't really a notion of multiqueue in the target side. The
multiqueue is implemented in the initiator side where each block device
supports multiple submission queues. This is supported in the block
layer and the scsi layer.
In the context of iscsi, in order to support multiqueue we need to
actually open multiple sessions towards the target and each session
will set as a submission queue. This requires the iscsi stack to change
by exposing "session group" for each IT-nexus.
A short while ago, I spent some time working on it (with mike's help).
I have an experimental code that actually does this and able to get
better performance, but it's partial, not very stable and still has some
unresolved issues due to the way the iscsi stack is currently
designed (different models of sw and hw offloads). So we still have
some way to go.
I was pulled away to other activities but I do plan to get back in
the very near future. You are more than welcome to join the effort.
There are a couple of good slides on scsi multiqueue online, but you've
probably read those.
I am a bit reluctant though to post any patches of what is a really
partial shaky implementation at the moment.
Sagi.
--
To unsubscribe from this list: send the line "unsubscribe target-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
