Date: Wed, 27 Mar 2002 17:13:51 -0500 From: Jake Burkholder <jake@locore.ca> To: John Baldwin <jhb@FreeBSD.ORG> Cc: Julian Elischer <julian@elischer.org>, arch@FreeBSD.ORG Subject: Re: SMP safe reference counting Message-ID: <20020327171351.E31836@locore.ca> In-Reply-To: <XFMail.20020327165157.jhb@FreeBSD.org>; from jhb@FreeBSD.ORG on Wed, Mar 27, 2002 at 04:51:57PM -0500 References: <Pine.BSF.4.21.0203271150430.47944-100000@InterJet.elischer.org> <XFMail.20020327165157.jhb@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Apparently, On Wed, Mar 27, 2002 at 04:51:57PM -0500, John Baldwin said words to the effect of; > > On 27-Mar-2002 Julian Elischer wrote: > > > > [please remove -smp from your reply] > > > > Once again on the SMP list a lock is being used to make a reference count > > safe. I'd like to re-raise the issue of a safe reference counting > > fascility. > > > > what would be the semantics? > > I have refcount.patch :) What would be nice is to first implement > atomic_fetchadd() (xadd on 486+, some hack on 386, fetchadd on ia64, similar to > atomic_add on sparc64, alpha, and powerpc I believe, basically it would add a > value to a memory location and return the result). You can then use taht for > the reference_release (or whatever you call it). We could also use that to get > rid of the really bloated debug version that uses a mutex and have a much > smaller debug version that still uses atomic ops. We support 386 still? > > -- > > John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ > "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-arch" in the body of the message 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?20020327171351.E31836>