From owner-freebsd-hackers Mon Feb 12 15:44:28 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from earth.backplane.com (earth-nat-cw.backplane.com [208.161.114.67]) by hub.freebsd.org (Postfix) with ESMTP id 57BC637B491 for ; Mon, 12 Feb 2001 15:44:25 -0800 (PST) Received: (from dillon@localhost) by earth.backplane.com (8.11.2/8.9.3) id f1CNhd053320; Mon, 12 Feb 2001 15:43:39 -0800 (PST) (envelope-from dillon) Date: Mon, 12 Feb 2001 15:43:39 -0800 (PST) From: Matt Dillon Message-Id: <200102122343.f1CNhd053320@earth.backplane.com> To: Dag-Erling Smorgrav Cc: Greg Lehey , Danny Braniss , freebsd-hackers@FreeBSD.ORG Subject: Re: soft updates performance References: <20010213095300.D2178@wantadilla.lemis.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :> In fact, it's exactly the opposite. 'make world' is CPU-bound, so the :> speed of the I/O system is irrelevant. If it were I/O bound, soft :> updates *would* make a difference, because a number of unnecessary :> writes would be eliminated. : :Read what he writes. Soft updates *did* make a difference - they :shaved ~30% off his worldstone. It's parallelization that doesn't make :a difference in his case, because his CPU and FSB are fast enough that :the I/O system is left completely in the dust. This is a 900 MHz box, :probably with a 100 MHz or 133 MHz FSB, not the old 486DX33 you have :lying in a corner. : :DES :-- :Dag-Erling Smorgrav - des@ofug.org A suspect a good chunk of that is not using -pipe. I would be interested in buildworld numbers with -pipe vs with -pipe + softupdates. Without -pipe softupdates will make a huge difference due to temporary file creation & deletion. When Kirk first tested softupdates against buildworld, he explicitly tested it with and without -pipe and found that much of the performance benefit (for buildworld) occured when not using -pipe. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message