Date: Tue, 12 Jan 1999 21:01:57 -0700 (MST) From: "Kenneth D. Merry" <ken@plutotech.com> To: axl@iafrica.com (Sheldon Hearn) Cc: hackers@FreeBSD.ORG Subject: Re: what was the old devstat interface's dk_wds? Message-ID: <199901130401.VAA49342@panzer.plutotech.com> In-Reply-To: <40018.916184080@axl.noc.iafrica.com> from Sheldon Hearn at "Jan 13, 99 01:34:40 am"
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Sheldon Hearn wrote... > > Hi folks, > > I'm trying to teach sysutils/xosview about the new kernel device > statistics interface so that its DiskMeter will work for CURRENT. At the > moment, it expects FreeBSD to use "the older method" for pulling device > statistics out of the kernel. > > I'm getting to grips with devstat(3) and the source for iostat, but I > still need to understand how "the older method" worked, so that I can > translate what xosview wants to do into what it should do. > > I would greatly appreciate it if someone could help me with one of the > following: > > 1) A pointer to the devstat(3) manpage's predecessor. I don't think there was a predecessor. You'll have to read the source. Check out a -current from sometime before Sept. 15th, 1998. > OR > > 2) An explanation of the timeframe context for a comment like this one > from STABLE's /usr/include/sys/dkstat.h: > > extern long dk_wds[DK_NDRIVE]; /* # blocks of 32*16-bit words transferred */ > > It's the number of 32*16-bit words transferred since when? Since boot, I believe. One of the problems with that is that it's a 32 bit signed value on i386, and so would probably wrap every so often on a server with a lot of I/O going on. devstat uses 64 bit counters, so it's much more difficult for them to wrap. There are a couple of other ports that use the devstat code, in addition to systat(1), vmstat(8), and iostat(8). Check out xperfmon, and xsysinfo. I think they both support devstat. If you've got questions, just ask. I wrote the devstat code. Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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