lkml.org 
[lkml]   [2009]   [Jun]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: only clear node_states for 64bit
On Mon, 22 Jun 2009 08:38:50 -0700
Yinghai Lu <yinghai@kernel.org> wrote:

> Nathan reported that
> | commit 73d60b7f747176dbdff826c4127d22e1fd3f9f74
> | Author: Yinghai Lu <yinghai@kernel.org>
> | Date: Tue Jun 16 15:33:00 2009 -0700
> |
> | page-allocator: clear N_HIGH_MEMORY map before we set it again
> |
> | SRAT tables may contains nodes of very small size. The arch code may
> | decide to not activate such a node. However, currently the early boot
> | code sets N_HIGH_MEMORY for such nodes. These nodes therefore seem to be
> | active although these nodes have no present pages.
> |
> | For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too
>
> the cpuset.mems cgroup attribute on an i386 kvm guest
>
> fix it by only clearing node_states[N_NORMAL_MEMORY] for 64bit only.
> and need to do save/restore for that in find_zone_movable_pfn
>

There appear to be some words omitted from this changelog - it doesn't
make sense.

I think that perhaps a line got deleted before "the cpuset.mems cgroup
...". That was the line which actualy describes the bug which we're
fixing. Or perhaps it was a single word? "zeroes".


I did this:

Nathan reported that
:
: | commit 73d60b7f747176dbdff826c4127d22e1fd3f9f74
: | Author: Yinghai Lu <yinghai@kernel.org>
: | Date: Tue Jun 16 15:33:00 2009 -0700
: |
: | page-allocator: clear N_HIGH_MEMORY map before we set it again
: |
: | SRAT tables may contains nodes of very small size. The arch code may
: | decide to not activate such a node. However, currently the early boot
: | code sets N_HIGH_MEMORY for such nodes. These nodes therefore seem to be
: | active although these nodes have no present pages.
: |
: | For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too
:
: unintentionally and incorrectly clears the cpuset.mems cgroup attribute on
: an i386 kvm guest
:
: Fix this by only clearing node_states[N_NORMAL_MEMORY] for 64bit only.
: and need to do save/restore for that in find_zone_movable_pfn

Please check whether that is correct. If not, how should it be changed?



\
 
 \ /
  Last update: 2009-06-26 22:59    [W:0.167 / U:0.456 seconds]
©2003-2011 Jasper Spaans. Advertise on this site