From owner-freebsd-hackers Thu Nov 22 15:32:41 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from acl.lanl.gov (acl.lanl.gov [128.165.147.1]) by hub.freebsd.org (Postfix) with SMTP id 6D67337B405 for ; Thu, 22 Nov 2001 15:32:39 -0800 (PST) Received: (qmail 884081 invoked from network); 22 Nov 2001 16:32:37 -0700 Received: from snaresland.acl.lanl.gov (128.165.147.113) by acl.lanl.gov with SMTP; 22 Nov 2001 16:32:37 -0700 Received: (qmail 24116 invoked by uid 3499); 22 Nov 2001 16:32:37 -0700 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 22 Nov 2001 16:32:37 -0700 Date: Thu, 22 Nov 2001 16:32:37 -0700 (MST) From: Ronald G Minnich X-X-Sender: To: Harti Brandt Cc: Mike Meyer , Subject: Re: sysctls for hardware monitoring? In-Reply-To: <20011122103611.V451-100000@beagle.fokus.gmd.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Thu, 22 Nov 2001, Harti Brandt wrote: > What's bad about using files? Just to be different? Isn't it easier to > select, poll, kqueue, what ever on files than on sysctls? /proc files are horrible if you sample at reasonable rates, say 10-100 hz. We found (on Linux, maybe fbsd is better) that sampling rpc.rstatd at 10 hz. ate 10% of a 500 Mhz. PII. ouch. We also found that sampling rpc.rstatd took > 10 MILLISECONDS on the same machine. Moving to sysctl we found we could sample at 1Khz. with no significant load on the machine. See the Supermon paper at ALS2001 for more info. ron To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message