lkml.org 
[lkml]   [2012]   [Sep]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch for-3.6] mm, thp: fix mapped pages avoiding unevictable list on mlock
On Wed, 19 Sep 2012, Hugh Dickins wrote:

> Good catch, and the patch looks right to me, as far as it goes:
> but does it go far enough?
>
> I hesitate because it looks as if the NR_MLOCK zone page state is
> maintained (with incs and decs) in ignorance of THP; so although
> you will be correcting the Unevictable kB with your mlock_vma_page(),
> the Mlocked kB just above it in /proc/meminfo would still be wrong?
>

Indeed, NR_MLOCK is a separate problem with regard to thp and it's
currently incremented once for every hugepage rather than HPAGE_PMD_NR.
mlock_vma_page() needs to increment by hpage_nr_pages(page) like
add_page_to_lru_list() does.

> I suppose I'm not sure whether this is material for late-3.6:
> surely it's not a fix for a recent regression?
>

Ok, sounds good. If there's no objection, I'd like to ask Andrew to apply
this to -mm and remove the cc to stable@vger.kernel.org since the
mlock_vma_page() problem above is separate and doesn't conflict with this
code, so I'll send a followup patch to address that.

Thanks!


\
 
 \ /
  Last update: 2012-09-27 04:01    [W:0.987 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site