Date: Mon, 16 Dec 1996 12:11:40 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: mo@UU.NET (Mike O'Dell) Cc: smp@freebsd.org Subject: Re: smp technology..... Message-ID: <199612161911.MAA01775@phaeton.artisoft.com> In-Reply-To: <QQbuic14582.199612161032@rodan.UU.NET> from "Mike O'Dell" at Dec 16, 96 05:32:23 am
next in thread | previous in thread | raw e-mail | index | archive | help
> i assume folks have read the smp paper that appeared in Computing Systems > several years ago by the folks at Amdahl?? they did an smp implementation > where most of the work was done by transforming the SPLn() calls > (essentially with a SED script) and then getting the interrupt stuff > right. > > they compared their experimental implementation with a fine-grain-locking > implementation and discovered that the experimental system had better > large-scale multiprogramming throughput because it did did significantly > less convoying. (convoying is a phenomenon where processes line up > and progress through a series of locks single-file like a convoy. > i always thought a conga-line was a better visual image, but > "convoying" is the term in the literature.) "Several years ago" says "SVR4.0.2 ES/MP" or "Sequent" to me... both of these have acknowledged concurrency problems in their device access, and even in their FS code itself. If this was the comparison, I'd like to see another one against UnixWare 2.x (forget Solaris; Sun did their FS synchronization at the wrong level). I suspect it would not do nearly so well (unless they leap-frogged UnixWare's UFS's DOW with soft updates or something). Regards, 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?199612161911.MAA01775>