From owner-freebsd-hackers  Thu Nov  4  9:24:31 1999
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Date: Thu, 4 Nov 1999 09:23:04 -0800
From: Arun Sharma <adsharma@home.com>
To: "Matthew N. Dodd" <winter@jurai.net>
Cc: freebsd-hackers@FreeBSD.ORG
Subject: Re: kstat - an API for gathering kernel stats
Message-ID: <19991104092304.A708@home.com>
References: <19991103215642.A31757@home.com> <Pine.BSF.4.20.9911040251030.18969-100000@sasami.jurai.net>
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In-Reply-To: <Pine.BSF.4.20.9911040251030.18969-100000@sasami.jurai.net>; from Matthew N. Dodd on Thu, Nov 04, 1999 at 02:53:51AM -0500
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On Thu, Nov 04, 1999 at 02:53:51AM -0500, Matthew N. Dodd wrote:
> On Wed, 3 Nov 1999, Arun Sharma wrote:
> > A user program makes a system call with this string "cpu.system" to get
> > the current value of user/system/nice time etc.
> 
> How is this different from doing:
> 
> # sysctl -a | grep load
> vm.loadavg: { 0.15 0.09 0.04 }
> 
> Ideally we could have a syscall that could return the OID for a given name
> to solve the portability and speed issues associated with doing repeated
> lookups.
> 
> Seems like you've reinvented the wheel to me.

I just looked at the sysctl implementation and there are some differences.
Moreover, since it was not being used in tools like vmstat and xosview,
I thought there must be a reason.

sysctl also seems to assume that it doesn't get called frequently. So
mapping the name to the sysctl data is a slightly more heavy duty
operation than a hash table lookup.

	-Arun


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