Date: Wed, 3 Sep 2003 21:49:50 -0700
From: "David S. Miller" <davem@redhat.com>
To: Larry McVoy <lm@bitmover.com>
Cc: mbligh@aracnet.com, piggin@cyberone.com.au, anton@samba.org,
       lm@bitmover.com, linux-kernel@vger.kernel.org
Subject: Re: Scaling noise
Message-Id: <20030903214950.26e0b430.davem@redhat.com>
In-Reply-To: <20030903153901.GB5769@work.bitmover.com>
References: <20030903040327.GA10257@work.bitmover.com>
	<20030903041850.GA2978@krispykreme>
	<20030903042953.GC10257@work.bitmover.com>
	<20030903062817.GA19894@krispykreme>
	<3F55907B.1030700@cyberone.com.au>
	<27780000.1062602622@[10.10.2.4]>
	<20030903153901.GB5769@work.bitmover.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1215
Lines: 29

On Wed, 3 Sep 2003 08:39:01 -0700
Larry McVoy <lm@bitmover.com> wrote:

> It's really easy to claim that scalability isn't the problem.  Scaling
> changes in general cause very minute differences, it's just that there
> are a lot of them.  There is constant pressure to scale further and people
> think it's cool.

So why are people still going down this path?

I'll tell you why, because as SMP issues start to embark upon
the mainstream boxes people are going to find clever solutions
to most of the memory sharing issues that cause all the "lock
overhead".

Things like RCU are just the tip of the iceberg.  And think Larry,
we didn't have stuff like RCU back when you were directly working
and watching people work on huge SMP systems.

I think it's instructive to look at hyperthreading from another
angle in this argument, that the cpu people invested billions of
dollars in work to turn memory latency into free cpu cycles.

Put that in your pipe and smoke it :-)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/