Date: Tue, 30 Nov 1999 22:42:22 +0900 From: "Daniel C. Sobral" <dcs@newsguy.com> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: freebsd-arch@freebsd.org Subject: Re: Threads and the scheduler Message-ID: <3843D43E.4F40A642@newsguy.com> References: <3842DBB5.8AFC9B6@newsguy.com> <199911292022.MAA08694@apollo.backplane.com>
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Matthew Dillon wrote: > > No, it won't, because most context switches are synchronous and > the tick interval doesn't apply in those cases. Asynchronizing > I/O does not necessarily mean that the calling thread will continue to > run. If it has nothing to do it is going to exit or go to sleep whether > the I/O is asynchronous or not. It is definitely not going to waste > cpu finishing out its quanta. Mmmm... that's not exactly what I'm worried about. I'm thinking of applications which use threads to handle both i/o and cpu-bound tasks. Our scheduler raises the i/o-bound tasks priority and lowers cpu-bound tasks priority. With a program using threads to do both, the scheduler would end up treating the process as cpu-bound and lower it's priority. Ok, maybe that's fault of the application design, but still... :-) Processes with enough i/o-bound tasks to actually use up all quanta before running out of threads will suffer from a similar fate. -- Daniel C. Sobral (8-DCS) who is as social as a wampas dcs@newsguy.com dcs@freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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