kernelnewbies.kernelnewbies.org archive mirror
 help / color / mirror / Atom feed
From: Valdis.Kletnieks@vt.edu (Valdis.Kletnieks at vt.edu)
To: kernelnewbies@lists.kernelnewbies.org
Subject: zap_low_mappings
Date: Wed, 06 Mar 2013 22:19:28 -0500	[thread overview]
Message-ID: <8572.1362626368@turing-police.cc.vt.edu> (raw)
In-Reply-To: Your message of "Thu, 07 Mar 2013 10:33:18 +0800." <20130307023318.GA2940@debian.localdomain>

On Thu, 07 Mar 2013 10:33:18 +0800, ishare said:
>
>   kernel halts because the page mapping has been modified by zap_low_mappings
>
>
>   why we should do zap_low_mappings in init procedure ? this will disorder the page mapping.

You might want to get yourself an up to date kernel, as the code you're
asking about was removed almost 2 1/.2 years ago.

zap_low_mappings was removed in October 2010 by this commit:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/x86/mm/init_32.c?id=b40827fa7268fda8a62490728a61c2856f33830b

x86-32, mm: Add an initial page table for core bootstrapping

This patch adds an initial page table with low mappings used exclusively for
booting APs/resuming after ACPI suspend/machine restart. After this, there's no
need to add low mappings to swapper_pg_dir and zap them later or create own
swsusp PGD page solely for ACPI sleep needs - we have initial_page_table for
that.

Signed-off-by: Borislav Petkov <bp@alien8.de>
LKML-Reference:<20101020070526.GA9588@liondog.tnic>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>


-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 865 bytes
Desc: not available
Url : http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20130306/2abb9c96/attachment-0001.bin 

  reply	other threads:[~2013-03-07  3:19 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-07  2:33 zap_low_mappings ishare
2013-03-07  3:19 ` Valdis.Kletnieks at vt.edu [this message]
2013-03-07  3:43   ` zap_low_mappings ishare
2013-03-07  4:00     ` zap_low_mappings Valdis.Kletnieks at vt.edu
2013-03-07  4:48       ` zap_low_mappings ishare
2013-03-07  5:34         ` zap_low_mappings Valdis.Kletnieks at vt.edu
2013-03-07 11:50           ` zap_low_mappings ishare

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=8572.1362626368@turing-police.cc.vt.edu \
    --to=valdis.kletnieks@vt.edu \
    --cc=kernelnewbies@lists.kernelnewbies.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
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).