LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
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

  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 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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20080309185752.GA9548@elte.hu \
    --to=mingo@elte.hu \
    --cc=arjan@linux.intel.com \
    --cc=hans.rosenfeld@amd.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --subject='Re: bisected boot regression post 2.6.25-rc3.. please revert' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).