Date: Thu, 04 Nov 2010 01:05:43 -0500 From: Alan Cox <alc@rice.edu> To: Andriy Gapon <avg@freebsd.org> Cc: Alan Cox <alc@freebsd.org>, freebsd-current@freebsd.org Subject: Re: minidump size on amd64 Message-ID: <4CD24D37.5060701@rice.edu> In-Reply-To: <4CD1B02E.2070708@freebsd.org> References: <4CA0DA49.2090006@freebsd.org> <4CA3A48A.5070300@freebsd.org> <4CA3BD1E.5070807@rice.edu> <4CA5911E.3000101@freebsd.org> <4CAE0060.7050607@freebsd.org> <4CAECC4D.90707@rice.edu> <4CD1AA45.7000504@freebsd.org> <4CD1AD80.2090903@rice.edu> <4CD1B02E.2070708@freebsd.org>
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Andriy Gapon wrote: > on 03/11/2010 20:44 Alan Cox said the following: > [snip] > > Thank you for the confirmation! > > >> Andriy Gapon wrote: >> >>> P.S. is there a macro for extracting frame address from PDPE? >>> >> To a lower level page table page or to a 1GB physical page? For the latter, you >> can use PG_PS_FRAME. >> > > To a 1GB page. > I see in the architecture manual that the lower bits are marked as MBZ, so this > macro should work. Actually, it seems that even PG_FRAME should work in place of > PG_PS_FRAME for exactly the same reason (MBZ) on amd64. > There is actually a point to using PG_PS_FRAME. The PAT bit for a 2MB page mapping occupies a bit that is a part of the physical page number with PG_FRAME. I suspect that the same is true of 1GB page mappings, but I haven't double checked the manual. Alan
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