From owner-freebsd-hackers Wed Mar 8 10:40:21 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from feral.com (feral.com [192.67.166.1]) by hub.freebsd.org (Postfix) with ESMTP id D65EC37C1EA for ; Wed, 8 Mar 2000 10:40:15 -0800 (PST) (envelope-from mjacob@feral.com) Received: from semuta.feral.com (semuta [192.67.166.70]) by feral.com (8.9.3/8.9.3) with ESMTP id KAA16979; Wed, 8 Mar 2000 10:40:04 -0800 Date: Wed, 8 Mar 2000 10:40:10 -0800 (PST) From: Matthew Jacob Reply-To: mjacob@feral.com To: Mohit Aron Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: enabling APIC without SMP In-Reply-To: <200003081829.MAA14589@cs.rice.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I'll second this request. > 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-hackers" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message