From owner-freebsd-arch Tue Feb 19 0:51:43 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16]) by hub.freebsd.org (Postfix) with ESMTP id 41E2737B402; Tue, 19 Feb 2002 00:51:39 -0800 (PST) Received: from bde.zeta.org.au (bde.zeta.org.au [203.2.228.102]) by mailman.zeta.org.au (8.9.3/8.8.7) with ESMTP id TAA21747; Tue, 19 Feb 2002 19:51:34 +1100 Date: Tue, 19 Feb 2002 19:51:34 +1100 (EST) From: Bruce Evans X-X-Sender: To: Matthew Dillon Cc: Greg Lehey , , Subject: Re: buildworld comparison stable vs current In-Reply-To: <200202190534.g1J5Y7s58322@apollo.backplane.com> Message-ID: <20020219194134.V1374-100000@gamplex.bde.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Mon, 18 Feb 2002, Matthew Dillon wrote: > The test boxes are DELL2550's, so 2xCPU (1.1GHz pentium III's), > ECC memory, SCSI drives. > > A couple of things have become obvious during my own testing: > > * Context switching for every interrupt is expensive > > stable: 2467550 voluntary context switches (buildworld -j 10) > current: 23879443 voluntary context switches (buildworld -j 10) These mostly aren't for interrupts (unless they are for IPIs). I get: 393580 voluntary context switches 355294 involuntary context switches for UP on an Athlon1600 (for a makeworld which took 1573 seconds in -current), i.e., only 1/60 as many voluntary context switches. I think most of them are for context switches to idle because Giant is held. The idle process is more of a mistake than I first thought. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message