From owner-cvs-all Tue Apr 3 20:16:54 2001 Delivered-To: cvs-all@freebsd.org Received: from isris.pair.com (isris.pair.com [209.68.2.39]) by hub.freebsd.org (Postfix) with SMTP id 1493637B724 for ; Tue, 3 Apr 2001 20:16:50 -0700 (PDT) (envelope-from rooneg@isris.pair.com) Received: (qmail 88567 invoked by uid 3130); 4 Apr 2001 03:16:49 -0000 Date: Tue, 3 Apr 2001 23:16:49 -0400 From: Garrett Rooney To: Bosko Milekic Cc: Matt Dillon , Alfred Perlstein , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/sys mbuf.h src/sys/kern uipc_mbuf.c Message-ID: <20010403231648.B59839@electricjellyfish.net> References: <200104030315.f333FCX69312@freefall.freebsd.org> <20010403140457.B2952@electricjellyfish.net> <200104031813.f33ID4b58965@earth.backplane.com> <20010403194004.A15434@technokratis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010403194004.A15434@technokratis.com>; from bmilekic@technokratis.com on Tue, Apr 03, 2001 at 07:40:04PM -0400 Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, Apr 03, 2001 at 07:40:04PM -0400, Bosko Milekic wrote: > The reason for the removal isn't related to pollution of system > structures per se (i.e. bloat). There were really only three locks, one > for each free list. > The removal is, the way I see it, a slight pessimization in some > cases at this moment, due to the increase of contention again, in some cases. > The removal was done nonetheless because it is a step forward toward PCPU > locks in the mbuf system. The idea is that prior to this removal, what > was happening is that in the easy uncontended case of allocation, it was > likely that `ping-ponging' from data cache to data cache would occur a > maximum of three times per allocation. In that same easy case, with one lock, > the cache invalidation will happen a maximum of once for what concerns the > mutex in that same case. ok, that makes more sense. [snip more discussion] > In other words, the decision to do this has been planned and > discussed. :-) Cool, that's what I figured, but I just wanted to figure out what the plan was, and this discussion has done that admirably ;-) i'd just like thank everyone who's been involved in the SMPng work, as it's been hugely inforamtive to sit on the sidelines and watch, and everyone has been really willing to answer questions whenever asked. -- garrett rooney Unix was not designed to stop you from rooneg@electricjellyfish.net doing stupid things, because that would http://electricjellyfish.net/ stop you from doing clever things. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message