From owner-freebsd-hackers Thu Mar 30 17:16:21 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id RAA07463 for hackers-outgoing; Thu, 30 Mar 1995 17:16:21 -0800 Received: from cs.weber.edu (cs.weber.edu [137.190.16.16]) by freefall.cdrom.com (8.6.10/8.6.6) with SMTP id RAA07451 for ; Thu, 30 Mar 1995 17:16:20 -0800 Received: by cs.weber.edu (4.1/SMI-4.1.1) id AA29972; Thu, 30 Mar 95 18:10:00 MST From: terry@cs.weber.edu (Terry Lambert) Message-Id: <9503310110.AA29972@cs.weber.edu> Subject: Re: help with splbio, splnet, spl... To: davidg@Root.COM Date: Thu, 30 Mar 95 18:09:59 MST Cc: vernick@cs.sunysb.edu, freebsd-hackers@FreeBSD.org In-Reply-To: <199503310019.QAA00334@corbin.Root.COM> from "David Greenman" at Mar 30, 95 04:19:31 pm X-Mailer: ELM [version 2.4dev PL52] Sender: hackers-owner@FreeBSD.org Precedence: bulk > >It's a tiered interrupt scheme. You can block all interrupts > >at or below a specified priority while you are doing high > >priority stuff so that it gets done in time. The "fast" > >interrupts can't be blocked. > > It doesn't work this way in FreeBSD. It is not a tierd interrupt scheme. > Each of the interrupt classes are independant and do NOT block the others. The > only exception to this is tty and net are ored together if you are using SLIP > or PPP (the reason should be obvious). This must be (relatively) new... Why isn't it tiered? This conflicts with what you said about splclock() and splhigh() in your previous post: ] splhigh() and splclock() block all interrupts except "fast" interrupts. Would it be more correct to say that it is partially tiered, with the potential for multiple interrupt classes in a single tier not interfering with each other? This would accomodate both the behaviour you are describing in this post and the quote from your previous post... Terry Lambert terry@cs.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.