From owner-freebsd-net Wed Jul 7 21:13:12 1999 Delivered-To: freebsd-net@freebsd.org Received: from sumatra.americantv.com (sumatra.americantv.com [208.139.222.227]) by hub.freebsd.org (Postfix) with ESMTP id 50B5F14FDF for ; Wed, 7 Jul 1999 21:13:10 -0700 (PDT) (envelope-from jlemon@americantv.com) Received: from right.PCS (right.PCS [148.105.10.31]) by sumatra.americantv.com (8.8.5/8.8.5) with ESMTP id XAA13753; Wed, 7 Jul 1999 23:13:09 -0500 (CDT) Received: (from jlemon@localhost) by right.PCS (8.6.13/8.6.4) id XAA25254; Wed, 7 Jul 1999 23:13:08 -0500 Message-ID: <19990707231308.40142@right.PCS> Date: Wed, 7 Jul 1999 23:13:08 -0500 From: Jonathan Lemon To: Mohit Aron Cc: freebsd-net@freebsd.org Subject: Re: paper on improving webserver performance References: <199907080340.WAA29430@free.pcs> <199907080346.WAA27087@cs.rice.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.61.1 In-Reply-To: <199907080346.WAA27087@cs.rice.edu>; from Mohit Aron on Jul 07, 1999 at 10:46:19PM -0500 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Jul 07, 1999 at 10:46:19PM -0500, Mohit Aron wrote: > > > > This seems to indicate that you still have the overhead where the timer > > fires, but no events are actually pending. > > True, but it avoids any pointer manipulations when timers are set and cancelled > by TCP (which happens much more). Only if a timer is set by TCP that needs to > fire earlier than the time that the timing wheel event handler needs to fire > would you need to move around the timing wheel event. Yes, I thought the same thing too. Originally, my implmentation simply moved all connections in a TIME_WAIT states onto a separate timing wheel, and left the rest of the code alone. Turns out that the overhead of inserting/deleting events from the timing wheel is trivial as compared to the cost of checking the hash buckets and walking the chains checking for events. > In any case, I'm very interested in your implementation since you appear to > have seen faster performance results with it. I'm just about done; wrapping up some testing and making sure I didn't break anything. -- Jonathan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message