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