Date: Thu, 15 Jul 1999 20:05:45 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: Doug@gorean.org (Doug) Cc: tlambert@primenet.com, davids@webmaster.com, chat@FreeBSD.ORG Subject: Re: Known MMAP() race conditions ... ? Message-ID: <199907152005.NAA04524@usr07.primenet.com> In-Reply-To: <378D91FD.AB21D216@gorean.org> from "Doug" at Jul 15, 99 00:47:09 am
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> > I'll argue the threads with you until I'm blue in the face, if > > you want. 8-). > > I don't want, because I'm not qualified to argue the point with you _or_ > DS. What I do know is that there are programs that use threads, and those > programs perform poorly on freebsd. Whether not supporting things that are > bad ideas (like threads might be) is the right tactical decision or not is > also beyond me, however you asked for a list, so there you have it. :) When > we spec'ed the servers I'm currently working on we never considered less > than 2 cpu's. This is a horse of a different wheelbase. FreeBSD doesn't have good general threads support at this time, though it (apparently) runs Linux threads better than Linux does, if you load that kernel module. This isn't an indication that kernel threads are good, just because the current implementation of the call conversion scheduler for the user space threads in FreeBSD isn't SMP scalable, since there's no technical reason it cant be. My fundamental point was that, with the possible exception of Solaris, no one does SMP scalable threads well, and even Solaris, by virtue of use of a kernel threading implementation with a hybridized scheduler, has its issues. And these issues are an attribute of thinking about problem solving using procedural logic, which is why people think of threads: it's a nice, comfortable paradigm that makes it so they don't have to think outside the box. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message
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