From: Andi Kleen <ak@linux.intel.com>
To: Bob Zhang <zhanglinbao@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
hayfeng Lee <omycle@gmail.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Bob Zhang <2004.zhang@gmail.com>
Subject: Re: x86_64 virtual memory map
Date: Tue, 26 Jul 2011 12:49:56 -0700 [thread overview]
Message-ID: <20110726194956.GA4117@tassilo.jf.intel.com> (raw)
In-Reply-To: <CAKdQVUZMC0eaeqev=tAbS2myHJOA1KJt4r8TVMz6=yQeDpUpZQ@mail.gmail.com>
> and in the end of mm.txt , it says :
> >>Current X86-64 implementations only support 40 bits of address space,
> >> 27but we support up to 46 bits. This expands into MBZ space in the
> >>page tables.
> so this 40bit(1TB) is responding to virtual memory map(1TB) ?
The 1TB limit was dropped a long time ago.
Your googling found an old file.
> 3, if I installed 64TB physical memory (RAM) , but linux kernel only
What system is that out of curiosity? Are you sure it's not
a cluster?
> support 1TB address space , what should I do next ?
There's no known 1TB limit currently.
However at least for Intel Xeons there is no CPU which supports
more than 16TB physical address space.
Are you sure you have your units correct?
The theoretical x86 kernel limits are higher and it should upto support
64TB. However since that's untested territory and there
have been bugs in large memory support in the past
you may run into problems.
Other architectures like IA64 will support more (but you
may be also in untested territory)
I believe 4+TB x86 systems have been tested.
-Andi
next prev parent reply other threads:[~2011-07-26 19:50 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-25 2:20 x86_64 virtual memory map hayfeng Lee
2010-03-26 4:34 ` Eric W. Biederman
2011-07-25 10:13 ` Bob Zhang
2011-07-25 10:17 ` Bob Zhang
2011-07-25 10:33 ` Eric W. Biederman
2011-07-26 8:43 ` Bob Zhang
2011-07-26 19:26 ` Valdis.Kletnieks
2011-07-26 19:49 ` Andi Kleen [this message]
2011-07-27 7:13 ` Bob Zhang
2011-07-27 15:38 ` Andi Kleen
2011-08-19 15:13 ` Bob Zhang
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=20110726194956.GA4117@tassilo.jf.intel.com \
--to=ak@linux.intel.com \
--cc=2004.zhang@gmail.com \
--cc=ebiederm@xmission.com \
--cc=linux-kernel@vger.kernel.org \
--cc=omycle@gmail.com \
--cc=zhanglinbao@gmail.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