Date: Mon, 14 Jan 2002 10:58:59 -0500 From: Bosko Milekic <bmilekic@technokratis.com> To: "James E. Housley" <jeh@FreeBSD.ORG> Cc: Terry Lambert <tlambert2@mindspring.com>, Thomas Hurst <tom.hurst@clara.net>, arch@FreeBSD.ORG Subject: Re: 64 bit counters again Message-ID: <20020114105859.A24635@technokratis.com> In-Reply-To: <3C42E899.CB21BD0A@FreeBSD.org>; from jeh@FreeBSD.ORG on Mon, Jan 14, 2002 at 09:18:01AM -0500 References: <Pine.BSF.4.41.0201132057560.62182-100000@prg.traveller.cz> <3C41F3FD.4ECC8CD@mindspring.com> <20020113231459.GA30349@voi.aagh.net> <3C42390A.F9E9F533@mindspring.com> <3C42E899.CB21BD0A@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jan 14, 2002 at 09:18:01AM -0500, James E. Housley wrote: > Terry Lambert wrote: > > > > My personal opinion is that the utility of the counters is > > mostly in the examination of small deltas, or delta measurement > > over intervals (c.v. the recent "sar" discussion); is there a > > particular reason that making them more expensive to get 64 > > bits of accuracy is needed to fulfill? > > > > Right now I am trying to do network usage on the overflows the 32 bit > counters in 60 120 seconds. That means the netstat values are useless, > mrtg and other programs that poll for results every 5 minutes or so are > useless. If I want to get good data I have to get the counts every 10 > seconds or so to get reasonable results. You know, if you have a counter overflowing in 60 to 120 seconds, then perhaps what it's counting should not be counted to begin with. I stumbled upon several statistics issues while writing mb_alloc and I tried to the best of my abilities to group the manipulation of the counters under some common already existing lock. In some odd cases, this was impossible. But I refused to introduce a bus-locked instruction or, worse, a whole new lock just to deal with the statistics. It's too much overhead for mere statistics and, in the latter case, it's even very bug-prone. To be honest, after actually examining more closely what the counters collected statistics on, I realized that they were pretty much totally redundant and am considering removing those few problematic ones some time in the future. > Jim > -- > /"\ ASCII Ribbon Campaign . > \ / - NO HTML/RTF in e-mail . > X - NO Word docs in e-mail . > / \ ----------------------------------------------------------------- > jeh@FreeBSD.org http://www.FreeBSD.org The Power to Serve > jim@TheHousleys.Net http://www.TheHousleys.net > jhousley@SimTel.Net http://www.SimTel.Net > --------------------------------------------------------------------- > "It's a damn poor mind that can only think of one way to > spell a word." > -- Andrew Jackson Regards, -- Bosko Milekic bmilekic@FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020114105859.A24635>