lkml.org 
[lkml]   [2012]   [Aug]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mm: correct page->pfmemalloc to fix deactivate_slab regression
On Mon, Aug 13, 2012 at 08:14:35PM +0800, Alex Shi wrote:
> commit cfd19c5a9ec (mm: only set page->pfmemalloc when
> ALLOC_NO_WATERMARKS was used) try to narrow down page->pfmemalloc
> setting, but it missed some places the pfmemalloc should be set.
>
> So, in __slab_alloc, the unalignment pfmemalloc and ALLOC_NO_WATERMARKS
> cause incorrect deactivate_slab() on our core2 server:
>
> 64.73% fio [kernel.kallsyms] [k] _raw_spin_lock
> |
> --- _raw_spin_lock
> |
> |---0.34%-- deactivate_slab
> | __slab_alloc
> | kmem_cache_alloc
> | |
>
> That causes our fio sync write performance has 40% regression.
>
> This patch move the checking in get_page_from_freelist, that resolved
> this issue.
>
> Signed-off-by: Alex Shi <alex.shi@intel.com>

Acked-by: Mel Gorman <mgorman@suse.de>

--
Mel Gorman
SUSE Labs


\
 
 \ /
  Last update: 2012-08-13 15:03    [W:0.034 / U:0.432 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site