From owner-freebsd-alpha Tue Jan 2 12:57:10 2001 From owner-freebsd-alpha@FreeBSD.ORG Tue Jan 2 12:57:07 2001 Return-Path: Delivered-To: freebsd-alpha@freebsd.org Received: from front7m.grolier.fr (front7m.grolier.fr [195.36.216.57]) by hub.freebsd.org (Postfix) with ESMTP id 4C2CE37B69D; Tue, 2 Jan 2001 12:57:06 -0800 (PST) Received: from nas1-172.cgy.club-internet.fr (nas1-172.cgy.club-internet.fr [195.36.197.172]) by front7m.grolier.fr (8.9.3/No_Relay+No_Spam_MGC990224) with ESMTP id VAA09642; Tue, 2 Jan 2001 21:56:59 +0100 (MET) Date: Tue, 2 Jan 2001 20:56:36 +0100 (CET) From: =?ISO-8859-1?Q?G=E9rard_Roudier?= X-Sender: groudier@linux.local To: Matthew Jacob Cc: John Baldwin , alpha@FreeBSD.ORG, Doug Rabson Subject: RE: Interrupt threads In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, 2 Jan 2001, Matthew Jacob wrote: > You switch to the process w/o changing IPL. It is resumed at the IPL of t= he > ithread that blocked. In the software way of looking at it, it inherits t= he > priority of the ithread until it releases the lock that caused it to be > resumed. Just a tiny question and remark: We must keep in mind (at it I have this in mind) that IPL is a thing local to a CPU but MUTEXes are global synchronisation objects. What happens if a ithread want to acquire a MUTEX owned by a thread=20 running on another CPU ? In my $0.02 humble opinion, I think that we should probably be able from an ithread to just spinlock on a MUTEX that is already owned, unless we are believing in miracles. > > > 4. What defeated me immediately upon looking at Doug's stuff is all o= f the > > > thread pri seems to be a software construct, so has no real hardware > > > linkage. Additionally, I did not take the time to try and find an eas= y way to > > > find and reschdule the proc that holds a lock if I'm trying to acquir= e it > > > from > > > an ithread and am blocking. Seems to be a bit of work there. IMO, the real issue is pointed here. G=E9rard. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message