From owner-freebsd-smp Wed May 1 10:48:10 2002 Delivered-To: freebsd-smp@freebsd.org Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by hub.freebsd.org (Postfix) with ESMTP id F32A937B416 for ; Wed, 1 May 2002 10:48:02 -0700 (PDT) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.9.3/8.9.3) with ESMTP id NAA10648; Wed, 1 May 2002 13:48:02 -0400 (EDT) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.11.6/8.9.1) id g41HlW218398; Wed, 1 May 2002 13:47:32 -0400 (EDT) (envelope-from gallatin@cs.duke.edu) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15568.10804.364425.409745@grasshopper.cs.duke.edu> Date: Wed, 1 May 2002 13:47:32 -0400 (EDT) To: Terry Lambert Cc: freebsd-smp@freebsd.org Subject: Re: hlt when idle? In-Reply-To: <3CD022A2.FACD21E9@mindspring.com> References: <15567.62317.677224.3470@grasshopper.cs.duke.edu> <3CD022A2.FACD21E9@mindspring.com> X-Mailer: VM 6.75 under 21.1 (patch 12) "Channel Islands" XEmacs Lucid Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Terry Lambert writes: > Andrew Gallatin wrote: > > Can somebody remind me why we do not hlt in the idle loop on MP x86s? > > Halting with "giant" and/or "the scheduler lock" held is bad. Ug. We hold locks in the idle loop?? > > Do both CPUs get clock interrupts on x86? > > The clock interrupts may or may not be routed via the APIC; > routing of the clock interrupt is one of the most common > bogosities that you have to handle on x86 SMP systems; there > is a special printf for complaining about having to work > around broken BIOS and/or motherboard circuitry. Is this what you mean: APIC_IO: Testing 8254 interrupt delivery APIC_IO: Broken MP table detected: 8254 is not connected to IOAPIC #0 intpin 2 APIC_IO: routing 8254 via 8259 and IOAPIC #0 intpin 0 This was taken from the machine which seems to work just fine with halting in the idle loop... (Serverworks LE based SuperMicro 370DLE) Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message