Subject: SOFTDEP, a second data point
To: None <,>
From: Jim Wise <>
List: tech-kern
Date: 12/12/1999 20:45:12
Hash: SHA1

Having been using my laptop with softdep enabled on all filesystems
since the day it was commited with no problems, I decided to take this
weekend to enable softdep on the rest of my -current systems.

In addition, in order to get some performance numbers slightly more
useful than `it feels faster', I ran the following test on my home
fileserver / i386 build server:

	1.) rebuild kernel with softdep compiled in.
	2.) make build
	3.) time /usr/bin/make build 2>&1 | tee build.1.log
	4.) reboot off of /altroot and enable softdep on all drives,
	    / included.
	5.) time /usr/bin/make build 2>&1 | tee build.2.log

The machine in question is an i386 with a PII-266, 64 MB RAM, and all
filesystems on a 9GB 7200 RPM IBM drive on an AIC7880 wide ultra SCSI
controller.  The machine serves SMB, Appleshare, and NFS to my home lan
segments, but all clients were quiescent throughout the test, and the
server was otherwise idle.  The system does not currently use a memfs on
/tmp, which is very relevant to this test. The initial `make build'
served to assure that both builds had to `make cleandir' a fully
populated object hierarchy, and to make sure that identical versions of
all utilities were used throughout.

The results were as follows:

The first build (softdep not enabled anywhere):

	Build started at: Sun Dec 12 11:53:16 EST 1999
	Build finished at: Sun Dec 12 15:01:39 EST 1999
	    11302.97 real      6225.54 user      1850.15 sys

The second build (softdep enabled on all filesystems, including / (which
includes /tmp):

	Build started at: Sun Dec 12 15:15:16 EST 1999
	Build finished at: Sun Dec 12 17:50:25 EST 1999
	     9309.22 real      6179.97 user      1935.87 sys

11302.97 seconds (~ 3:08:23) was reduced to 9309.22 seconds (~ 2:35:09),
a speed improvement of 18%.  Not too shabby, IMHO.

Later tonight or tomorrow I will perform bonnie benchmarks before and
after converting my remaining unconverted client machine, a PII-333.

- -- 
				Jim Wise

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