Date: Tue, 13 Jul 2004 08:57:54 -0700 From: Marcel Moolenaar <marcel@xcllnt.net> To: "Yang M.M." <youngdream8039@hotmail.com> Cc: freebsd-ia64@freebsd.org Subject: Re: does FreeBSD have "per-CPU page" ? Message-ID: <20040713155754.GB8277@dhcp50.pn.xcllnt.net> In-Reply-To: <BAY19-F8PDVXLuSbh290004afba@hotmail.com> References: <BAY19-F8PDVXLuSbh290004afba@hotmail.com>
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On Tue, Jul 13, 2004 at 02:54:59AM +0000, Yang M.M. wrote: > Hi all, > Linux/ia64 has a "per-CPU page" in region 5 just after "gate page". The > per-CPU page provides one page of CPU-local data,which is useful on MP > machines. > My question is : does FreeBSD have such a page? If so, where is it? Yes and no. There is per-CPU data, but it's not necessarily a page and definitely is not wired at a fixed virtual address. The address of the per-CPU data is in pcpup. This happens to be register 13 (TP). It is saved in ar.k4, from which pcpup (=r13) is restored on entry into the kernel. -- Marcel Moolenaar USPA: A-39004 marcel@xcllnt.net
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