From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <13426df10807170558g2782802n7039faf142c221b7@mail.gmail.com> Date: Thu, 17 Jul 2008 05:58:23 -0700 From: "ron minnich" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@9fans.net> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: Cc: rvs@sun.com Subject: Re: [9fans] 8 cores Topicbox-Message-UUID: ea575fc8-ead3-11e9-9d60-3106f5b1d025 On Thu, Jul 17, 2008 at 5:41 AM, erik quanstrom wrote: > as you've pointed out, performance-wise it's not copying vs. nothing > it's copying vs page faults and trips through the vm code. > i would think playing vm games (as linus likes to say) would make > scheduling on mp harder > But you make trips through the vm code on read/write in any event, don't you? There was a pretty good paper comparing these paths once and in the end it boiled down to "your cost will vary depending on how you wrote the kernel" :-) This problem has been worked for a long time by Sun among others. They've had several decades to think on it. ron