From owner-freebsd-hackers Mon Feb 12 17:49:21 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 7D64937B491 for ; Mon, 12 Feb 2001 17:49:17 -0800 (PST) Received: (from dillon@localhost) by earth.backplane.com (8.11.2/8.9.3) id f1D1nDr66705; Mon, 12 Feb 2001 17:49:13 -0800 (PST) (envelope-from dillon) Date: Mon, 12 Feb 2001 17:49:13 -0800 (PST) From: Matt Dillon Message-Id: <200102130149.f1D1nDr66705@earth.backplane.com> To: Kent Stewart Cc: Dag-Erling Smorgrav , Greg Lehey , Danny Braniss , freebsd-hackers@FreeBSD.ORG Subject: Re: soft updates performance References: <20010213095300.D2178@wantadilla.lemis.com> <200102122343.f1CNhd053320@earth.backplane.com> <3A887EB3.6BDD7648@urx.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :Thunderbird 900, with 256 MB of PC-133 memory, and using 3 - ATA-66 :HD's on different controllers. The elapsed time dropped from 58:16 to :45:54 by using softupdates. : :Kent That sounds about right for -pipe. The original email was 1 hour vs 40 minutes, a 20 minute difference which seemed a bit high (what I would expect without -pipe). 46 minutes verses 58 minutes is only a 12 minute 20 second difference, which is more inline with what I would expect. Most of the savings is occuring during the dependancy and cleaning step(s). The system creates and deletes a huge number of files in a huge number of directories and softupdates really helps there. Softupdates is not helping much during the actual compilation, which is a cpu-bound step if you use -pipe (the creation of the object files costs nothing because there is no other disk activity going on). The buildworld hits various choke points -- even with -j 128, if there are only 30 files in a library you will generally only see 30 compiles going at once. The final library link stage chokes it down to one process and this will become a pure bandwidth issue for your disk subsystem for a second or so (for the larger libraries). -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message