From owner-freebsd-smp Wed Mar 8 16:15:25 2000 Delivered-To: freebsd-smp@freebsd.org Received: from cs.rice.edu (cs.rice.edu [128.42.1.30]) by hub.freebsd.org (Postfix) with ESMTP id CC9BC37B696 for ; Wed, 8 Mar 2000 16:15:22 -0800 (PST) (envelope-from aron@cs.rice.edu) Received: (from aron@localhost) by cs.rice.edu (8.9.0/8.9.0) id SAA04483 for freebsd-smp@freebsd.org; Wed, 8 Mar 2000 18:15:21 -0600 (CST) Date: Wed, 8 Mar 2000 18:15:21 -0600 (CST) From: Mohit Aron Message-Id: <200003090015.SAA04483@cs.rice.edu> To: freebsd-smp@freebsd.org Subject: enabling APIC without SMP Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi, I'm using a FreeBSD-current snapshot from 3rd January 2000. It seems that in order to enable APICs (option APIC_IO in kernel configuration file), one needs to also compile the kernel with SMP support (option SMP in kernel configuration file). While enabling the APIC is desirable even on a uniprocessor (provides more IRQs, interrupt ovhd becomes less, provides on-chip timer), enabling SMP support on a uniprocessor brings down the performance (I've noticed a degradation of 22% in performance of a webserver when a kernel was compiled with SMP support than without). Would it be possible to allow enabling the APIC without requiring support for SMP in future versions of FreeBSD ? Since I'm using a snapshot that's about two months old, I apologize if the above has already been addressed in the latest snapshots. - Mohit To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message From owner-freebsd-smp Thu Mar 9 17:24:39 2000 Delivered-To: freebsd-smp@freebsd.org Received: from mass.cdrom.com (mass.cdrom.com [204.216.28.184]) by hub.freebsd.org (Postfix) with ESMTP id A3E1337B995 for ; Thu, 9 Mar 2000 17:24:36 -0800 (PST) (envelope-from msmith@mass.cdrom.com) Received: from mass.cdrom.com (localhost [127.0.0.1]) by mass.cdrom.com (8.9.3/8.9.3) with ESMTP id RAA01891; Thu, 9 Mar 2000 17:26:00 -0800 (PST) (envelope-from msmith@mass.cdrom.com) Message-Id: <200003100126.RAA01891@mass.cdrom.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: Mohit Aron Cc: freebsd-smp@freebsd.org Subject: Re: enabling APIC without SMP In-reply-to: Your message of "Wed, 08 Mar 2000 18:15:21 CST." <200003090015.SAA04483@cs.rice.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 09 Mar 2000 17:26:00 -0800 From: Mike Smith Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org I don't believe that anyone has actually done any work on this, sorry. > I'm using a FreeBSD-current snapshot from 3rd January 2000. It seems > that in order to enable APICs (option APIC_IO in kernel configuration file), > one needs to also compile the kernel with SMP support (option SMP in kernel > configuration file). While enabling the APIC is desirable even on a > uniprocessor (provides more IRQs, interrupt ovhd becomes less, provides > on-chip timer), enabling SMP support on a uniprocessor brings down the > performance (I've noticed a degradation of 22% in performance of a webserver > when a kernel was compiled with SMP support than without). Would it be possible > to allow enabling the APIC without requiring support for SMP in future > versions of FreeBSD ? > > Since I'm using a snapshot that's about two months old, I apologize if the > above has already been addressed in the latest snapshots. > > > > - Mohit > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-smp" in the body of the message > -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message