Date: Thu, 07 Mar 2002 17:16:39 -0500 (EST) From: John Baldwin <jhb@FreeBSD.org> To: Matthew Jacob <mjacob@feral.com> Cc: 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: <XFMail.020307171639.jhb@FreeBSD.org> In-Reply-To: <Pine.BSF.4.21.0203061448290.23706-100000@beppo>
next in thread | previous in thread | raw e-mail | index | archive | help
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. 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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?XFMail.020307171639.jhb>