lkml.org 
[lkml]   [2007]   [Oct]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Interaction between Xen and XFS: stray RW mappings
Andi Kleen wrote:
> It's hidden now so it causes any obvious failures any more. Just
> subtle ones which is much worse.
>

I think anything detected by Xen is still classed as "obscure" ;)

> But why not just disable it? It's not critical functionality,
> just a optimization that unfortunately turned out to be incorrect.
>
> It could be made correct short term by not freeing the pages until
> vunmap for example.
>

I think it only ends up holding 64 pages (or is it 64 mappings?), so its
not a horrible use of memory. Particularly since it responds to memory
pressure callbacks.

>> does his grand unified vmap manager. I guess a clean workaround would
>> be to add a CONFIG_XFS_LAZY_UNMAP, and do it at the Kconfig level...
>> I'll cook up a patch.
>>
>
> This option could only be safely set in architectures that don't
> care about caching attribute aliases or never remap kernel pages
> uncached. That's not x86, powerpc, ia64 at a minimum.
>
> I think the only good short term fix is to turn your ifdef CONFIG_XEN
> into a #if 0
>

#if 1, but yes, I see your point.

J
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-10-22 21:15    [W:0.094 / U:0.188 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site