linux-kernel - Re: Re: HT (Hyper Threading) aware process scheduling doesn't work as it should

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Message-ID: <1179048211.51348.1320013764432.JavaMail.mail@webmail17>
Date:	Sun, 30 Oct 2011 22:29:23 +0000 (GMT)
From:	"Artem S. Tashkinov" <t.artem@...os.com>
To:	arjan@...radead.org
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Re: HT (Hyper Threading) aware process scheduling doesn't work
 as it should

> On Oct 31, 2011, Arjan van de Ven wrote:
>
> On Sun, 30 Oct 2011 19:57:12 +0000 (GMT)
> "Artem S. Tashkinov" wrote:
>
> > Hello,
> >
> > It's known that if you want to reach maximum performance on HT
> > enabled Intel CPUs you should distribute the load evenly between
> > physical cores, and when you have loaded all of them you should then
> > load the remaining virtual cores.
>
> this is a bold statement, and patently false if you have to threads of
> one process that heavily share data between eachother...
> (but true for more independent workloads)

In my initial message I was talking about completely unrelated tasks/
processes which share no data/instructions/whatever else. You don't
need to trust my test case as you can carry out this test on your own.

I have asked quite a lot of people to do that and a lot of them see this
unfortunate pattern. 
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