[ofa-general] Re: Scalable reliable connection

Michael S. Tsirkin mst at dev.mellanox.co.il
Tue Jul 31 05:07:06 PDT 2007


> Quoting Gleb Natapov <glebn at voltaire.com>:
> Subject: Re: Scalable reliable connection
> 
> On Mon, Jul 30, 2007 at 03:50:54PM +0300, Michael S. Tsirkin wrote:
> > With SRC:
> > 		O(N ^ 2 * J)
> > 
> > 	This is achived by using a single send queue (per job, out of O(N * J) jobs)
> > 	to send data to all J jobs running on a specific node (out of O(N) nodes).
> > 	Hardware uses new "SRQ number" field in packet header to
> > 	multiplex receive WRs and WCs to private memory of each job.
> > 
> But since the send queue cannot be used for receiving packets additional
> receive QPs have to be created one per job so with SRC it is actually
>     O(N ^ 2 * J + N * J)
> unless I am missing something.

Yes but since N >= 1, N ^ 2 >= N and so O(N ^ 2 * J + N * J) == O(N ^ 2 * J).

-- 
MST



More information about the general mailing list