Date: Thu, 7 Mar 2002 17:34:50 -0500 From: Jake Burkholder <jake@locore.ca> To: John Baldwin <jhb@FreeBSD.org> Cc: Matthew Jacob <mjacob@feral.com>, Jeff Roberson <jeff@FreeBSD.org>, cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Subject: Re: cvs commit: src/sys/sys smp.h src/sys/kern subr_smp.c src/sy Message-ID: <20020307173450.A12044@locore.ca> In-Reply-To: <XFMail.020307171639.jhb@FreeBSD.org>; from jhb@FreeBSD.org on Thu, Mar 07, 2002 at 05:16:39PM -0500 References: <Pine.BSF.4.21.0203061448290.23706-100000@beppo> <XFMail.020307171639.jhb@FreeBSD.org>
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Apparently, On Thu, Mar 07, 2002 at 05:16:39PM -0500, John Baldwin said words to the effect of; > > On 06-Mar-02 Matthew Jacob wrote: > > > >> If someone wants to make them virtual then they can do it I suppose. > >> However, that doesn't help if you ever want to support the notion of > >> removing and adding CPU's at runtime. You would still have to deal with > >> sparse ID's in that case, so maybe it's just better to not assume packed > >> ID's to begin with? > > > > Well, yes and no. There's two issues here. Yes, you should assume a sparse > > space. But it's also convenient to know that there's some bounded (less than > > 1000, e.g.) number of CPUs so you can do arrays sizes, etc. It would also be > > able to index conveniently off of some number related to the currently > > running > > CPU instead of going "I'm CPU-ID 0x7abcdefg..hmm. Now let me search my > > database so I can find the softc that corresponds to this....". > > Yes, well, the current Alpha ID's do fit this model. :) I think you want what > we already have. If we do end up with an arch which uses 64-bit phyiscal ID > numbers or other such weirdness then it is free to assign logical ID's as it > sees fit. We just happen to use the phyiscal ID for the virtaul ID on Alpha, > i386 (and sparc64 I believe) since they do fit these requirements. Just to clarify, its a logical id on sparc64, not guaranteed to be equal to the hardware id. > > Does that make sense? I'm not say we need to support some wildly sparse range, > but we shouldn't assume 0 and 1 for any dual CPU system. > > -- > > 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 cvs-all" in the body of the message
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