9fans archive / 2001 / 08 / 403 / prev next From: forsyth@cal... Subject: Re: [9fans] EROS, Vapour Date: Fri, 31 Aug 2001 09:53:59 +0100 mode, all synchronizing via cheap test&set processor instructions, whereas in Plan9/etc. an expensive switch to kernel mode is required, making heavily parallel things unpractical (the cost of mutexes becomes higher than the gain of parallelism). i don't know about the `etc.' but in Plan 9, at least, if your application could manage with only test and set processor instructions on Vapour it would manage on Plan 9, using ... errr... test and set instructions at user mode.