From: Ed L Cashin <ecashin@uga.edu>
To: linux-kernel <linux-kernel@vger.kernel.org>
Cc: trivial <trivial@rustcorp.com.au>
Subject: [TRIVIAL][PATCH] document unused pte bits on i386
Date: Thu, 07 Aug 2003 11:23:34 -0400 [thread overview]
Message-ID: <87n0elwky1.fsf@uga.edu> (raw)
Hi. This small patch documents that bits 9, 10, and 11 are unused by
the Linux kernel. The IA-32 Intel Architecture Software Developer's
Manual says that these bits are available for programmer use.
I checked and couldn't see any use of these bits in the Linux kernel.
If I'm wrong and these bits *are* being used by the linux kernel, a
comment in include/asm-i386/pgtable.h would be helpful. If they are
not, this patch confirms for developers that the kernel isn't using
these bits.
--- linux-2.6.0-test2/include/asm-i386/pgtable.h~ Sun Jul 27 13:06:27 2003
+++ linux-2.6.0-test2/include/asm-i386/pgtable.h Thu Aug 7 11:16:36 2003
@@ -118,6 +118,9 @@
#define _PAGE_DIRTY 0x040
#define _PAGE_PSE 0x080 /* 4 MB (or 2MB) page, Pentium+, if present.. */
#define _PAGE_GLOBAL 0x100 /* Global TLB entry PPro+ */
+#define _PAGE_UNUSED1 0x200 /* available for programmer */
+#define _PAGE_UNUSED2 0x400
+#define _PAGE_UNUSED3 0x800
#define _PAGE_FILE 0x040 /* set:pagecache unset:swap */
#define _PAGE_PROTNONE 0x080 /* If not present */
--
--Ed L Cashin | PGP public key:
ecashin@uga.edu | http://noserose.net/e/pgp/
next reply other threads:[~2003-08-07 15:23 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-08-07 15:23 Ed L Cashin [this message]
2003-08-07 15:46 ` [TRIVIAL][PATCH] document unused pte bits on i386 Ed L Cashin
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=87n0elwky1.fsf@uga.edu \
--to=ecashin@uga.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=trivial@rustcorp.com.au \
/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).