From owner-freebsd-current Mon Sep 22 19:16:46 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id TAA08506 for current-outgoing; Mon, 22 Sep 1997 19:16:46 -0700 (PDT) Received: from usr01.primenet.com (tlambert@usr01.primenet.com [206.165.6.201]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id TAA08501 for ; Mon, 22 Sep 1997 19:16:44 -0700 (PDT) Received: (from tlambert@localhost) by usr01.primenet.com (8.8.5/8.8.5) id TAA00163; Mon, 22 Sep 1997 19:16:25 -0700 (MST) From: Terry Lambert Message-Id: <199709230216.TAA00163@usr01.primenet.com> Subject: Re: callouts in CAM (was Re: cvs commit:) To: gibbs@plutotech.com (Justin T. Gibbs) Date: Tue, 23 Sep 1997 02:16:24 +0000 (GMT) Cc: nate@mt.sri.com, gibbs@plutotech.com, bde@zeta.org.au, current@FreeBSD.ORG In-Reply-To: <199709222106.PAA02060@pluto.plutotech.com> from "Justin T. Gibbs" at Sep 22, 97 03:06:21 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-current@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > >Fair enough. Does the new scheme allow for dynamic allocation of > >callouts? I noticed that was on the TODO list for the original authors. > > Yes, but it's still not implemented. I think that we should push this > onto the client instead of attempting to do some kind of low water-mark > early allocation. In other words, allocate a fairly small initial pool > for most applications and then have systems like CAM allocate a callout > on an as-needed basis. You don't think it should be watermarked? I am a fan of low watermark based allocation scheduling (not necessarily immediate allocation, unless the pool empties). Mostly, I like this because the pools can be per CPU, and thus you don't take a global resource lock in the SMP case. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.