Date: Tue, 14 Jun 2005 13:44:02 +0200 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Sue Howard <howardsue@gmail.com> Cc: arch@freebsd.org, ken@freebsd.org Subject: Re: [DCR] Remove devstat Message-ID: <36765.1118749442@critter.freebsd.dk> In-Reply-To: Your message of "Tue, 14 Jun 2005 19:33:01 %2B0800." <1e89cd510506140433437f7b7@mail.gmail.com>
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In message <1e89cd510506140433437f7b7@mail.gmail.com>, Sue Howard writes: >Hi, > >I found devstat is not widely used in the device drivers. Based the >grep result of 'devstat_new_entry', it shows only cam, ata, fd, >geom_disk are using it. In my workstation, the output of 'sysctl >kern.devstat' shows: >I am wondering if devstat can be replaced by the sysctl nodes %desc, >%pnpinfo etc that jhb introduced. Almost all the information devstat >can provide can be also exposed by such sysctl node. Uhm, are we confused here ? Devstat is what is used for collecting transaction statistics for disks and scsi general devices in general. Programs like iostat and gstat uses it. The old access path (iostat) uses sysctls, but the new and practically overhead free access path is mmap(2) which gstat uses. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
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