From: Rick van Rein <rick@vanrein.org>
To: Craig Bergstrom <craigb@google.com>
Cc: "Luck, Tony" <tony.luck@intel.com>,
Andi Kleen <andi@firstfloor.org>,
Stefan Assmann <sassmann@kpanic.de>,
Matthew Garrett <mjg59@srcf.ucam.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"mingo@elte.hu" <mingo@elte.hu>, "hpa@zytor.com" <hpa@zytor.com>,
"rick@vanrein.org" <rick@vanrein.org>,
"rdunlap@xenotime.net" <rdunlap@xenotime.net>
Subject: Re: [PATCH v2 0/3] support for broken memory modules (BadRAM)
Date: Fri, 24 Jun 2011 08:05:35 +0000 [thread overview]
Message-ID: <20110624080535.GA19966@phantom.vanrein.org> (raw)
In-Reply-To: <BANLkTikTTCU3eKkCtrbLbtpLJtksehyEMg@mail.gmail.com>
Hi Craig,
> We (Google) are working on a data-driven answer for this question. I know
> that there has been some analysis on this topic on the past, but I don't
> want to speculate until we've had some time to put all the pieces together.
The easiest way to do this could be to take the algorithm from Memtest86
and apply it to your data, to see if it finds suitable patterns for the
cases tried.
By counting bits set to zero in the masks, you could then determine how
'tight' they are. A mask with all-ones covers one memory page; each
zero bit in the mask (outside of the CPU's page size) doubles the number
of pages covered.
You can ignore the address over which the mask is applied, although you
would then be assuming that all the pages covered by the mask are indeed
filled with RAM.
You would want to add the figures for the different masks.
I am very curious about your findings. Independently of those, I am in
favour of a patch that enables longer e820 tables if it has no further
impact on speed or space.
Cheers,
-Rick
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-06-24 8:05 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-22 11:18 [PATCH v2 0/3] support for broken memory modules (BadRAM) Stefan Assmann
2011-06-22 11:18 ` [PATCH v2 1/3] Add string parsing function get_next_ulong Stefan Assmann
2011-06-22 11:18 ` [PATCH v2 2/3] support for broken memory modules (BadRAM) Stefan Assmann
2011-06-22 11:18 ` [PATCH v2 3/3] Add documentation and credits for BadRAM Stefan Assmann
2011-06-22 18:00 ` [PATCH v2 0/3] support for broken memory modules (BadRAM) Andrew Morton
2011-06-22 18:06 ` Josh Boyer
2011-06-22 18:09 ` Randy Dunlap
2011-06-22 18:11 ` Nancy Yuen
2011-06-22 18:13 ` H. Peter Anvin
2011-06-22 19:01 ` Nancy Yuen
2011-06-22 19:06 ` H. Peter Anvin
2011-06-22 18:24 ` Andi Kleen
2011-06-22 18:38 ` Andrew Morton
2011-06-22 18:56 ` Andi Kleen
2011-06-22 19:05 ` H. Peter Anvin
2011-06-22 19:15 ` Andi Kleen
2011-06-22 20:25 ` H. Peter Anvin
2011-06-22 20:28 ` Andi Kleen
2011-06-22 19:46 ` [PATCH] x86: e820: Eliminate bubble sort from sanitize_e820_map Mike Ditto
2011-06-22 20:18 ` [PATCH v2 0/3] support for broken memory modules (BadRAM) Stefan Assmann
2011-06-23 10:33 ` Rick van Rein
2011-06-23 10:49 ` Rick van Rein
2011-06-23 10:10 ` Rick van Rein
2011-06-22 18:15 ` H. Peter Anvin
2011-06-22 20:30 ` Stefan Assmann
2011-06-22 20:33 ` H. Peter Anvin
2011-06-23 13:39 ` Matthew Garrett
2011-06-23 14:08 ` Stefan Assmann
2011-06-23 14:12 ` Matthew Garrett
2011-06-23 15:37 ` Stefan Assmann
2011-06-23 16:30 ` H. Peter Anvin
2011-06-24 0:59 ` Andi Kleen
2011-06-23 17:00 ` Andi Kleen
2011-06-23 17:12 ` Luck, Tony
2011-06-24 1:03 ` Craig Bergstrom
2011-06-24 1:08 ` Andi Kleen
2011-06-24 1:22 ` Craig Bergstrom
2011-06-24 8:05 ` Rick van Rein [this message]
2011-06-24 14:34 ` Craig Bergstrom
2011-06-24 16:16 ` H. Peter Anvin
2011-06-24 16:40 ` Luck, Tony
2011-06-24 16:56 ` Rick van Rein
2011-06-24 17:14 ` H. Peter Anvin
[not found] <fa.fHPNPTsllvyE/7DxrKwiwgVbVww@ifi.uio.no>
2011-06-24 21:10 ` Shane Nay
2011-06-28 2:33 ` Craig Bergstrom
2011-06-29 8:08 ` Rick van Rein
2011-06-29 15:28 ` craig lkml
2011-06-29 16:06 ` Craig Bergstrom
2011-06-29 21:24 ` Tony Luck
2011-06-30 14:32 ` Jody Belka
-- strict thread matches above, loose matches on Subject: below --
2011-06-21 9:23 Stefan Assmann
2011-06-21 22:02 ` Andrew Morton
2011-06-22 11:11 ` Stefan Assmann
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=20110624080535.GA19966@phantom.vanrein.org \
--to=rick@vanrein.org \
--cc=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=craigb@google.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@elte.hu \
--cc=mjg59@srcf.ucam.org \
--cc=rdunlap@xenotime.net \
--cc=sassmann@kpanic.de \
--cc=tony.luck@intel.com \
/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).