From: Ingo Molnar <mingo@elte.hu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: 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>
Subject: Re: bisected boot regression post 2.6.25-rc3.. please revert
Date: Sun, 9 Mar 2008 19:57:52 +0100 [thread overview]
Message-ID: <20080309185752.GA9548@elte.hu> (raw)
In-Reply-To: <alpine.LFD.1.00.0803091007560.5896@woody.linux-foundation.org>
* Linus Torvalds <torvalds@linux-foundation.org> 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!
>
> So my suggested patch would:
>
> - make the page table code use a specific mask that it builds up itself,
> and makes sure it's of the right type and has the rigth value in
> whatever type "struct pte_entry" is. The fact that "pte_val()" is
> larger than "unsigned long" on x86-32 is very clearly a PTE issue,
> *not* an issue for PAGE_SIZE or PAGE_MASK.
yeah, indeed my patch was sloppy, i didnt think it through - i fell for
the lure of the easy-looking 'PAGE_SIZE is small, sign-extend it' hack.
Will do it cleanly and will also clean up all the pte/address/pgprot
type mixing that currently goes on in this maze of macros.
Ingo
next prev parent reply other threads:[~2008-03-09 18:58 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-01 18:56 bisected boot regression post 2.6.25-rc3.. please revert 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 [this message]
2008-03-10 2:45 ` Jeremy Fitzhardinge
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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