From owner-freebsd-hackers Sat Feb 10 23:47:18 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 E996337B401 for ; Sat, 10 Feb 2001 23:47:00 -0800 (PST) Received: (from dillon@localhost) by earth.backplane.com (8.11.1/8.9.3) id f1B7iwS30465; Sat, 10 Feb 2001 23:44:58 -0800 (PST) (envelope-from dillon) Date: Sat, 10 Feb 2001 23:44:58 -0800 (PST) From: Matt Dillon Message-Id: <200102110744.f1B7iwS30465@earth.backplane.com> To: Greg Black Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: soft updates performance References: <200102102245.f1AMj1328151@earth.backplane.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :OK, I'm sold on the general idea of using soft updates; but what :sort of performance improvements should I expect to see? : :I do a kernel compile on a freshly-rebooted box with an without :softupdates; without, it took 20m45s and with soft updates it :still took 20m10s --- this is less than 3% faster, which is :close to statistically insignificant. Is this expected, or is :there some other factor I should look at? : :Greg A kernel compile, like a buildworld, is more a cpu-intensive operation then a disk-intensive operation, so I wouldn't expect a big improvement. Softupdates wins big on anything that does a lot of directory manipulation. For example, extracting a tar archive, rm -rf, news systems, mail systems (to a lesser degree since they fsync() a lot anyway), and general workloads. There is no real downside, so there really isn't any reason to *not* use softupdates. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message