From: Suparna Bhattacharya <suparna@in.ibm.com>
To: rddunlap@osdl.org
Cc: linux-kernel@vger.kernel.org, baldrick@wanadoo.fr,
lkcd-devel@lists.sourceforge.net
Subject: Re: Reserving physical memory at boot time
Date: Thu, 5 Dec 2002 13:43:54 +0530 [thread overview]
Message-ID: <20021205134354.A2363@in.ibm.com> (raw)
Crash dump after kexec also needs something similar, to
prevent the new kernel from allocating pages holding the dump from
the previous boot so that they aren't overwritten until the dump
gets written out. The pages can be accessed(read) for the purpose of
writeout. The Mission Critical implementation did this by patching
the kernel to mark these pages as reserved early during bootup,
much like the badmem mark pages as PG_Badmem.
There is a common theme running here of a "mark_claimed_pages"
logic during early bootup, and "is_claimed_page" check at
other places.
In the case of crash dump we have a fairly large number of
pages to be marked out this way. The layout is available in the
form of a map list, a pointer to which is passed on from the
previous reboot.
So if we are looking for very minimal infrastructure which all of
these can use, imposing a particular format in which such info
(about unavailable memory) be passed in could become either less
flexible or overgeneralized. Leaving the logic of identifying
pages to be claimed (not available to the kernel for allocation)
to the concerned subsystems appears to be a simpler and easier to
extend approach.
Is there a good way to avoid embedding calls to early mem
init code like mark_dump_pages, mark_bad_pages, mark_my_pages,
etc and instead have each of these subsystems specify interest
(a special section may be an overkill) so their corresponding
routines get called ?
Regards
Suparna
In article <Pine.LNX.4.33L2.0212031952530.7246-100000@dragon.pdx.osdl.net> Randy.Dunlap wrote:
> On 3 Dec 2002, James Stevenson wrote:
> | On Tue, 2002-12-03 at 12:03, Duncan Sands wrote:
> | > I would like to reserve a particular page of physical memory when
> | > the kernel boots. By reserving I mean that no one else gets to read
> | > from it or write to it: it is mine. Any suggestions for the best way
> | > to go about this with a 2.5 kernel?
> |
> | try having a look for the linux badmem patches i belive they might do
> | the same sort of thing.
> see http://badmem.sourceforge.net/
> --
> ~Randy
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
Suparna Bhattacharya (suparna@in.ibm.com)
Linux Technology Center
IBM Software Labs, India
next reply other threads:[~2002-12-05 8:04 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-05 8:13 Suparna Bhattacharya [this message]
-- strict thread matches above, loose matches on Subject: below --
2002-12-03 12:03 Reserving physical memory at boot time Duncan Sands
2002-12-03 21:11 ` Richard B. Johnson
2002-12-03 12:52 ` Duncan Sands
2002-12-03 22:14 ` Alan Cox
2002-12-03 21:58 ` Alan Cox
2002-12-03 22:18 ` bzeeb-lists
2002-12-04 13:25 ` Richard B. Johnson
[not found] ` <Pine.LNX.3.95.1021204082313.23777A-100000@chaos.analogic.c om>
2002-12-04 16:44 ` Mike Galbraith
2002-12-04 6:15 ` Duncan Sands
2002-12-05 5:44 ` Mike Galbraith
2002-12-04 17:01 ` Richard B. Johnson
2002-12-04 17:06 ` Randy.Dunlap
2003-03-05 5:44 ` H. Peter Anvin
2003-03-05 6:01 ` Randy.Dunlap
2003-03-05 15:04 ` H. Peter Anvin
2003-03-05 15:43 ` Randy.Dunlap
2003-03-05 15:48 ` H. Peter Anvin
2003-03-06 21:26 ` Pavel Machek
2003-03-06 23:24 ` H. Peter Anvin
2003-03-07 23:19 ` Pavel Machek
2003-03-09 21:08 ` H. Peter Anvin
2003-03-09 23:07 ` Randy.Dunlap
2002-12-03 23:23 ` James Stevenson
2002-12-04 3:53 ` Randy.Dunlap
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=20021205134354.A2363@in.ibm.com \
--to=suparna@in.ibm.com \
--cc=baldrick@wanadoo.fr \
--cc=linux-kernel@vger.kernel.org \
--cc=lkcd-devel@lists.sourceforge.net \
--cc=rddunlap@osdl.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).