Date: Thu, 05 Dec 2002 10:39:25 -0500 (EST) From: John Baldwin <jhb@FreeBSD.org> To: Terry Lambert <tlambert2@mindspring.com> Cc: Oliver Blasnik <oliver.blasnik@de.tiscali.com>, beemern <beemern@ksu.edu>, smp@FreeBSD.ORG Subject: Re: Intel SE7500CW2 narrowed down... Message-ID: <XFMail.20021205103925.jhb@FreeBSD.org> In-Reply-To: <3DEEAA5F.DDC9536F@mindspring.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 05-Dec-2002 Terry Lambert wrote: > John Baldwin wrote: >> >> Apparently both Linux and Windows use a different algorithm for starting >> >> up AP's on i386 in that (I think) they send broadcast IPI's instead of >> >> IPI'ing each CPU individually. >> > >> > This is why they work on old ASUS Pentium 90 boxes, and FreeBSD >> > does not. >> >> Well, considering FreeBSD started out working on Pentium 90 machines >> and has used the same algorithm since it first got SMP support, I >> am kind of skeptical that this is the source of the recent breakage >> of support for dual Pentiums. > > I own an ASUS Dual P90 box that was broken by the mpinit changes. > > >> > It's not related to the P4 SE7500CW2-type problems, which are >> > incorrect APIC description and chipset programming. >> >> In which way exactly? > > The chip isn't programmed to be able to direct interrupts to > other than the BP, unless it's in virtual wire mode. You can > deduce this, just by knowning the difference between the OS's > that do work on the board, and FReeBSD. Terry. Please be quiet until you know what is going on. IO interrupts work JUST FINE. It is ONLY the startup IPIs that are failing. This has NOTHING to do with IO APICs or virtual wire mode. Also, for your information, FreeBSD does NOT program the APIC to send all interrupts to one CPU. Rather, in 4.x, if an interrupt comes to a CPU when another CPU is in the kernel we use an IPI to "bounce" that interrupt over to the CPU already in the kernel manually. It is NOT done by programming the IO APIC. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?XFMail.20021205103925.jhb>