lkml.org 
[lkml]   [2013]   [Aug]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: Fix booting with DEBUG_PAGE_ALLOC with more than 512G RAM
On 08/12/2013 04:43 PM, Yinghai Lu wrote:
>> > commit 8170e6bed465b4b0c7687f93e9948aca4358a33b
>> > Author: H. Peter Anvin <hpa@zytor.com>
>> > Date: Thu Jan 24 12:19:52 2013 -0800
>> >
>> > x86, 64bit: Use a #PF handler to materialize early mappings on demand
> Before that, we have maping from [0,512M) in head_64.S, and we can
> spare two pages [0-1M). After that change, we can not reuse pages anymore.
>
> When we have more than 512M ram, we need extra page for pgd page with
> [512G, 1024g).
>
> Increase pages in BRK for page table to solve the booting problem.

So how much does this get us up to? 1TB? That's actually _fairly_
small today. I've got a fairly old machine with that much in it, and
it's only half full of DIMMs.

It's also a bit worrying that this is completely disconnected from the
other code in the kernel that is concerned with the amount of total
address space in the system: MAX_PHYSADDR_BITS.




\
 
 \ /
  Last update: 2013-08-13 02:01    [W:0.054 / U:0.140 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site