From: Jason Gunthorpe <jgg-uk2M96/98Pc@public.gmane.org>
To: Rohit Zambre <rzambre-sXc7qaQca9o@public.gmane.org>
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: 2x difference between multi-thread and multi-process for same number of CTXs
Date: Wed, 24 Jan 2018 15:22:40 -0700 [thread overview]
Message-ID: <20180124222240.GA10706@ziepe.ca> (raw)
In-Reply-To: <CAJ84Q-aMW7PXFFuODm6RN=SO342=tJ4_eSJ2TB0b8DLrxgwtGQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Wed, Jan 24, 2018 at 02:53:13PM -0600, Rohit Zambre wrote:
> Yes, that's correct. My concern was that during resource creation, the
> kernel was maybe sharing some resource for a process or that some sort
> of multiplexing was occurring to hardware contexts through control
> groups. Is it safe for me to conclude that separate, independent
> contexts/bfregs are being assigned when a process calls
> ibv_open_device multiple times?
I believe that is true.
There is no obvious point of contention if you use multiple contexts
and set the single threading flag..
Is it possible your benchmark is actually working differently in the
two modes? In a more broad sense, like the cluster network traffic
pattern is detrimental in the thread case for some reason?
Jason
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next prev parent reply other threads:[~2018-01-24 22:22 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-24 16:22 2x difference between multi-thread and multi-process for same number of CTXs Rohit Zambre
[not found] ` <CAJ84Q-aFfcXxaJS5rApcoow6SBjfZAvt71_OKo1ORorXAOZKbw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-24 17:08 ` Jason Gunthorpe
[not found] ` <20180124170830.GD16845-uk2M96/98Pc@public.gmane.org>
2018-01-24 20:53 ` Rohit Zambre
[not found] ` <CAJ84Q-aMW7PXFFuODm6RN=SO342=tJ4_eSJ2TB0b8DLrxgwtGQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-24 22:00 ` Anuj Kalia
[not found] ` <CADPSxAg62gpCTdD9rqVfz+hznVpa_yHig1PRvMeHs2SWc1fvsw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-26 16:44 ` Rohit Zambre
[not found] ` <CADPSxAj1wbNUqCpwigorpoQgGMVCAJ1TiQ5CuCxvSkVWd6LThQ@mail.gmail.com>
[not found] ` <CADPSxAj1wbNUqCpwigorpoQgGMVCAJ1TiQ5CuCxvSkVWd6LThQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-26 20:14 ` Rohit Zambre
[not found] ` <CAJ84Q-avu53954aECPKBHv2RR3KeH3ra4S+duLsFQeb3pp2+ww-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-26 22:34 ` Anuj Kalia
[not found] ` <CADPSxAgMeCdFsnrCAKLtGZp_aJp78LMB2VUObsr3_s-p6vu-MA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-02-07 0:02 ` Rohit Zambre
2018-01-24 22:22 ` Jason Gunthorpe [this message]
[not found] ` <20180124222240.GA10706-uk2M96/98Pc@public.gmane.org>
2018-01-24 23:04 ` Rohit Zambre
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