From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <421f9f47a15016332911bca0d49cd6fd@csplan9.rit.edu> To: 9fans@9fans.net Date: Wed, 4 Mar 2009 11:56:21 -0500 From: john@csplan9.rit.edu In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Subject: Re: [9fans] threads vs forks Topicbox-Message-UUID: b140f3ec-ead4-11e9-9d60-3106f5b1d025 >> it's interesting that parallel wasn't cool when chips were getting >> noticably faster rapidly. perhaps the focus on parallelization >> is a sign there aren't any other ideas. > > Gotta do something will all the extra transistors. After all, Moore's > law hasn't been repealed. And pipelines and traditional caches > are pretty good examples of dimishing returns. So multiple cores > seems a pretty straightforward approach. > > Now there is another use that would at least be intellectually interesting > and possible useful in practice. Use the transistors for a really big > memory running at cache speed. But instead of it being a hardware > cache, manage it explicitly. In effect, we have a very high speed > main memory, and the traditional main memory is backing store. > It'd give a use for all those paging algorithms that aren't particularly > justified at the main memory-disk boundary any more. And you > can fit a lot of Plan 9 executable images in a 64MB on-chip memory > space. Obviously, it wouldn't be a good fit for severely memory-hungry > apps, and it might be a dead end overall, but it'd at least be something > different... > > BLS 64 MB is enough to run a lot of Plan 9 apps and the kernel simultaneously, sure. But you can't fit Windows or Firefox in there, so it's probably not going to happen--if you can't fit either of the world's two most-used consumer apps, I don't think Intel will bother. Besides that, doing such a thing would involve departing from the hallowed CPU-cache-memory-swap-disk architecture we've held so dear since dinosaurs roamed the earth. Better off to just beef up the caches; there are big benefits and cash prizes to be had from higher L1 hit rates. John Floren