does FreeBSD have "per-CPU page" ?
Marcel Moolenaar
marcel at xcllnt.net
Tue Jul 13 08:57:55 PDT 2004
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 at xcllnt.net
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