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From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
	Arjan van de Ven <arjan@linux.intel.com>,
	hans.rosenfeld@amd.com, linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Jan Beulich <jbeulich@novell.com>
Subject: Re: bisected boot regression post 2.6.25-rc3.. please revert
Date: Sun, 09 Mar 2008 19:45:11 -0700	[thread overview]
Message-ID: <47D4A0B7.10905@goop.org> (raw)
In-Reply-To: <alpine.LFD.1.00.0803091007560.5896@woody.linux-foundation.org>

Linus Torvalds wrote:
> So I would *very* strongly instead argue:
>
>  - "unsigned long" is the native kernel type for all address manipulation, 
>    and thus "PAGE_SIZE" and "PAGE_MASK" should continue to have that type.
>
>  - anything that uses any other type without explicitly making sure it's 
>    safe is mis-using those macros. IOW, PAGE_MASk was *never* a type that 
>    had anything what-so-ever to do with page table entry bits, and this is 
>    purely a page table entry issue!
>   

Yes.  PTE_MASK already exists for masking the address bits out of a 
pte.  It should have the type pteval_t, which will deal with the PAE 
case cleanly.  It should also only have the middle pfn bits set, so that 
_PAGE_NX is also not included.

It's currently defined in terms of PHYSICAL_PAGE_MASK, which 1) is only 
used to define PTE_MASK, and 2) defined (wrongly) in terms of PAGE_MASK 
(though __PHYSICAL_MASK is correctly defined).

    J

  parent reply	other threads:[~2008-03-10  2:45 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-01 18:56 Arjan van de Ven
2008-03-03  7:46 ` Ingo Molnar
2008-03-03  9:13   ` Ingo Molnar
2008-03-03 16:41     ` Arjan van de Ven
2008-03-03 17:40       ` Ingo Molnar
2008-03-03 17:51         ` Nish Aravamudan
2008-03-03 17:55           ` Ingo Molnar
2008-03-03 17:58             ` H. Peter Anvin
2008-03-03 18:36         ` Arjan van de Ven
2008-03-03 18:44           ` Linus Torvalds
2008-03-03 22:00             ` Arjan van de Ven
2008-03-04  1:05               ` Arjan van de Ven
2008-03-04  6:53                 ` Ingo Molnar
2008-03-05 15:35                   ` Arjan van de Ven
2008-03-09 11:56             ` Ingo Molnar
2008-03-09 17:27               ` Linus Torvalds
2008-03-09 18:57                 ` Ingo Molnar
2008-03-10  2:45                 ` Jeremy Fitzhardinge [this message]
2008-03-10  4:35                 ` Paul Mackerras
2008-03-03 21:13           ` Segher Boessenkool
2008-03-03 21:22             ` Segher Boessenkool
2008-03-03 22:33               ` Segher Boessenkool
2008-03-03 22:55                 ` H. Peter Anvin
2008-03-03 22:56                 ` Jeremy Fitzhardinge
2008-03-03 23:04                   ` H. Peter Anvin
2008-03-04  6:58             ` Ingo Molnar
2008-03-03 17:15 ` Nish Aravamudan

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