From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 15 Oct 2009 21:53:28 +1100 From: Sam Watkins To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Message-ID: <20091015105328.GA18947@nipl.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) Subject: Re: [9fans] Barrelfish Topicbox-Message-UUID: 877ba1dc-ead5-11e9-9d60-3106f5b1d025 On Wed, Oct 14, 2009 at 06:50:28PM -0700, Roman Shaposhnik wrote: > > The mention that "... the overhead of cache coherence restricts the ability > > to scale up to even 80 cores" is also eye openeing. If we're at aprox 8 > > cores today, thats only 5 yrs away (if we double cores every > > 1.5 yrs). Sharing the memory between processes is a stupid approach to multi-processing / multi-threading. Modern popular computer architecture and software design is fairly much uniformly stupid. > A couple of years ago we had a Plan9 summit @Google campus and Ken was > there. I still remember the question he asked me: what exactly would you make > all those core do on your desktop? It's easy to write good code that will take advantage of arbitrarily many processors to run faster / smoother, if you have a proper language for the task. With respect to Ken, Bill Gates said something along the lines of "who would need more than 640K?". There is a vast range of applications that cannot be managed in real time using existing single-core technology. Sam