Date: Wed, 20 Aug 1997 16:48:55 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: perlsta@sunyit.edu (Alfred Perlstein) Cc: smp@csn.net, smp@FreeBSD.ORG, current@FreeBSD.ORG Subject: Re: SMP in a "production system" Message-ID: <199708202348.QAA21286@phaeton.artisoft.com> In-Reply-To: <Pine.BSF.3.96.970820013704.12319B-100000@server.local.sunyit.edu> from "Alfred Perlstein" at Aug 20, 97 01:39:41 am
next in thread | previous in thread | raw e-mail | index | archive | help
> a LOT of people told me that the SMP kernel/system is VERY stable, so far > are many things broken or is everything ok? The code snapshotted as of a day ago is relatively very stable. The date was chosen because some *potentially* destabilizing change are going in. The may do nothing but the *potentially* might. > I'm thinking about getting together an SMP system and was wondering how > the SMP system holds out against heavy load and other factors. Depends on yhow you load it. If you load it via threading, it's not much of a win, unless you use John's experimental stuff (this is hearsay, but it was heard from John, so it's probably "on good authority" 8-)). If you load it via processes, it depends on the relative amounts of user vs. kernel time since the kernel is not finely-grained reeentrant (yet). If it's mostly user process time (ie: things like "Apache" WWW servers, then it's a pretty big win, in my personal experience. For mostly pushing simultaneous text streams, it's about an 80% win. For compiling in parallel, it's maybe 50% (based on timing, but it's CPU intensive, so the number of parallel makes is not going to win much concurrency once there are as many as you have CPU's and they are crunching away; also compiling is relatively kernel intensive for some types of operations. So, bottom line, "some of us think so; your mileage may vary". Not the best answer, but as good as you will get from most commercial SMP OS vendors. 8-). Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199708202348.QAA21286>