From owner-freebsd-alpha Wed Jun 13 10:35:46 2001 Delivered-To: freebsd-alpha@freebsd.org Received: from meow.osd.bsdi.com (meow.osd.bsdi.com [204.216.28.88]) by hub.freebsd.org (Postfix) with ESMTP id 06C7D37B408; Wed, 13 Jun 2001 10:35:19 -0700 (PDT) (envelope-from jhb@FreeBSD.org) Received: from laptop.baldwin.cx (john@jhb-laptop.osd.bsdi.com [204.216.28.241]) by meow.osd.bsdi.com (8.11.3/8.11.2) with ESMTP id f5DHYf139798; Wed, 13 Jun 2001 10:34:41 -0700 (PDT) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: Date: Wed, 13 Jun 2001 10:34:44 -0700 (PDT) From: John Baldwin To: Doug Rabson Subject: Re: followup on 8 way SMP pani Cc: Andrew Gallatin , wilko@FreeBSD.org, freebsd-alpha@FreeBSD.org, Matthew Jacob Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On 13-Jun-01 Doug Rabson wrote: > On Wed, 13 Jun 2001, John Baldwin wrote: > >> >> On 13-Jun-01 Matthew Jacob wrote: >> > >> > >> > What I needed to fix for turbolaser is to clear the timer interrupt for >> > all >> > CPUs but the primary CPU- this is the TLINTRMASK{0,1} registers. But, >> > stupid >> > me, I upgraded my source first. >> >> Ok, then we will need to change how platform.clockintr works slightly. (It >> will need to do more) and then forward_*clock in sys/i386/i386/mp_machdep.c >> will need to be moved to sys/kern/subr_smp.c, and a few tweaks need to made >> to >> smp_handle_ipis() in alpha/alpha/mp_machdep.c, and the tlsb will need a >> custom >> platform.clockintr that handles clock interrupts the way x86 does by IPI'ing >> all other processses to go handle clock interrupts. Hmmm. Actually. >> >> You shouldn't even have to do this. SMP doesn't need the i8254 timecounter >> on >> the alpha actually, because we make it so that only the boot CPU actually >> messes with the timecounters, so a non-i8254 timecounter should work fine on >> SMP systems just fine right now. The reason I think dfr used hte i8254 >> before >> was that in pre-SMPng we did need to handle clock interrupts on whatever CPU >> owned the kernel lock, but now we don't have that same restriction. > > Are you saying that no code in the kernel calls nanotime(9) unless its > running on the boot cpu? If so, then we can use the alpha timecounter. If > not, then we need to find a decent clock somewhere in the tlaser hardware. > I'd loke to do the same for rawhide too since the i8254 really sucks. Argh. I forgot about that. I was thinking about clock interrupt issues. Turning off clock interrupts for slave CPU's won't fix that. :( -- John Baldwin -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message