public inbox for linux-rdma@vger.kernel.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
To: Konstantin Boyanov <boyanov-/DgOsau14IQ@public.gmane.org>
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: InfiniBand HCA loopback on a single host (subnet manager needed?)
Date: Wed, 9 Mar 2011 10:30:05 -0700	[thread overview]
Message-ID: <20110309173005.GN22729@obsidianresearch.com> (raw)
In-Reply-To: <alpine.LRH.2.00.1103090903140.15803-9mA5q7a405ob1SvskN2V4Q@public.gmane.org>

On Wed, Mar 09, 2011 at 09:04:39AM +0100, Konstantin Boyanov wrote:

> I think this is achievable on a single host by using the loopback
> capabilities of the InfiniBand HCA. The problem is, that I was not
> able to find a comprehensive description of how one sets up such
> loopback operation on the HCA chip.

To enable loopback I'm pretty sure you need an IB link on the
card, and a running SM to set the link the ACTIVE.

Also, be aware that in my experience loopback is a special case on IB
cards and the performance is not good, so testing in this manner may
not be valid.

If you have a dual port card you'd be better off connecting the ports
together and doing your test from port 1 to port 2.

Jason
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  parent reply	other threads:[~2011-03-09 17:30 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-09  8:04 InfiniBand HCA loopback on a single host (subnet manager needed?) Konstantin Boyanov
     [not found] ` <alpine.LRH.2.00.1103090903140.15803-9mA5q7a405ob1SvskN2V4Q@public.gmane.org>
2011-03-09 17:30   ` Jason Gunthorpe [this message]
     [not found]     ` <20110309173005.GN22729-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2011-03-09 18:24       ` Hal Rosenstock
     [not found]         ` <AANLkTimTm2UgUr4A_XJYGJpGBnRAFE74Eu6At+n9Xnfd-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-03-31  8:53           ` Konstantin Boyanov
     [not found]             ` <4D94411F.2080008-T5F83Mi6MZE@public.gmane.org>
2011-03-31 13:53               ` Hal Rosenstock

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110309173005.GN22729@obsidianresearch.com \
    --to=jgunthorpe-epgobjl8dl3ta4ec/59zmfatqe2ktcn/@public.gmane.org \
    --cc=boyanov-/DgOsau14IQ@public.gmane.org \
    --cc=linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox