From owner-freebsd-smp Wed Aug 27 13:40:08 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id NAA04891 for smp-outgoing; Wed, 27 Aug 1997 13:40:08 -0700 (PDT) Received: from Ilsa.StevesCafe.com (Ilsa.StevesCafe.com [205.168.119.129]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id NAA04872 for ; Wed, 27 Aug 1997 13:40:02 -0700 (PDT) Received: from Ilsa.StevesCafe.com (localhost [127.0.0.1]) by Ilsa.StevesCafe.com (8.8.7/8.8.5) with ESMTP id OAA29795; Wed, 27 Aug 1997 14:39:03 -0600 (MDT) Message-Id: <199708272039.OAA29795@Ilsa.StevesCafe.com> X-Mailer: exmh version 2.0gamma 1/27/96 From: Steve Passe To: Terry Lambert cc: petrilli@amber.org, mestery@winternet.com, peters@gil.com.au, smp@FreeBSD.ORG Subject: Re: A how does it work question. In-reply-to: Your message of "Wed, 27 Aug 1997 13:28:07 PDT." <199708272028.NAA06259@phaeton.artisoft.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 27 Aug 1997 14:39:03 -0600 Sender: owner-freebsd-smp@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Hi, > > - fast intrrrupts no longer use the giant lock. There is a simple lock that > > prevents more than 1 fast interrupt from being in the kernel at once, > > ... > > the kernel proper MP-safe, but each and EVERY driver needs work. > > Actually, you need a driver flag, and if it is not set, invoke the > simple lock. This would let you set the flag (MPSAFE?) on drivers > which didn't have the problem, and allow for a staged migration. > At least one driver needs to be safed before the resto of them can > be, using it as an example. thats already planned. sio.c and cy.c are already MP-safe from the kernel's point of view. The problem is that they are not 'concurrancy-safe', ie they never expected to be run concurrently by more than 1 CPU. This sort of problem is not so well demonstrated with an example driver, as the specific issues will vary from driver to driver. -- Steve Passe | powered by smp@csn.net | Symmetric MultiProcessor FreeBSD