| |
|
 |
|
 |
|
|
|
| |
|
|
xen-devel
[Xen-devel] Re: [PATCH 1/3] x86: calculate precisely the memory needed b
|
To: |
Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>, "H. Peter Anvin" <hpa@xxxxxxxxxxxxxxx> |
|
Subject: |
[Xen-devel] Re: [PATCH 1/3] x86: calculate precisely the memory needed by init_memory_mapping |
|
From: |
"H. Peter Anvin" <hpa@xxxxxxxxx> |
|
Date: |
Tue, 21 Jun 2011 11:02:43 -0700 |
|
Cc: |
"xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, "konrad.wilk@xxxxxxxxxx" <konrad.wilk@xxxxxxxxxx>, Stefano Stabellini <Stefano.Stabellini@xxxxxxxxxxxxx>, "linux-kernel@xxxxxxxxxxxxxxx" <linux-kernel@xxxxxxxxxxxxxxx>, "mingo@xxxxxxx" <mingo@xxxxxxx>, "yinghai@xxxxxxxxxx" <yinghai@xxxxxxxxxx> |
|
Delivery-date: |
Tue, 21 Jun 2011 11:23:35 -0700 |
|
Envelope-to: |
www-data@xxxxxxxxxxxxxxxxxxx |
|
In-reply-to: |
<alpine.DEB.2.00.1106211601570.12963@kaball-desktop> |
|
List-help: |
<mailto:xen-devel-request@lists.xensource.com?subject=help> |
|
List-id: |
Xen developer discussion <xen-devel.lists.xensource.com> |
|
List-post: |
<mailto:xen-devel@lists.xensource.com> |
|
List-subscribe: |
<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe> |
|
List-unsubscribe: |
<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe> |
|
References: |
<alpine.DEB.2.00.1106071849290.12963@kaball-desktop> <1307470409-7654-1-git-send-email-stefano.stabellini@xxxxxxxxxxxxx> <4DFFCBAD.9040507@xxxxxxxxxxxxxxx> <alpine.DEB.2.00.1106211601570.12963@kaball-desktop> |
|
Sender: |
xen-devel-bounces@xxxxxxxxxxxxxxxxxxx |
|
User-agent: |
K-9 Mail for Android |
Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> wrote:
>On Mon, 20 Jun 2011, H. Peter Anvin wrote:
>> On 06/07/2011 11:13 AM, stefano.stabellini@xxxxxxxxxxxxx wrote:
>> >
>> > - remove the extra page added on x86_32 for the fixmap because is
>not
>> > needed: the PMD entry is already allocated and contiguous for the
>whole
>> > range (a PMD page covers 4G of virtual addresses) and the pte entry
>is
>> > already allocated by early_ioremap_init.
>> >
>>
>> Hi Stefano,
>>
>> I think this is wrong. A PMD page covers *1G* of virtual addresses,
>and
>> in the 2+2 and 1+3 memory configurations, we may or may not need a
>> separate PMD for the fixmap.
>>
>> Am I missing something?
>
>You are right, a PMD page covers 1G of virtual addresses so that part
>of
>the explanation in the comment is wrong.
>
>The reason why we don't need a separate PMD for the fixmap is that in
>both PAE and non-PAE cases the last gigabyte of virtual addresses is
>always covered by the initial allocation in head_32.S (swapper_pg_dir
>or
>initial_pg_pmd).
Ok, wasn't sure if Xen used the static allocation or not.
--
Sent from my mobile phone. Please excuse my brevity and lack of formatting.
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
| |
|
Home