Re: [PATCH] slub Discard slab page only when node partials > minimum setting

["Alex,Shi" <alex.shi@intel.com>]

On Thu, 2011-09-15 at 13:40 +0800, Pekka Enberg wrote:
> On Thu, Sep 8, 2011 at 5:24 AM, Alex,Shi <alex.shi@intel.com> wrote:
> >> > BTW, some testing results for your PCP SLUB:
> >> >
> >> > for hackbench process testing:
> >> > on WSM-EP, inc ~60%, NHM-EP inc ~25%
> >> > on NHM-EX, inc ~200%, core2-EP, inc ~250%.
> >> > on Tigerton-EX, inc 1900%, :)
> >> >
> >> > for hackbench thread testing:
> >> > on WSM-EP, no clear inc, NHM-EP no clear inc
> >> > on NHM-EX, inc 10%, core2-EP, inc ~20%.
> >> > on Tigertion-EX, inc 100%,
> >> >
> >> > for  netperf loopback testing, no clear performance change.
> >> did you add my patch to add page to partial list tail in the test?
> >> Without it the per-cpu partial list can have more significant impact to
> >> reduce lock contention, so the result isn't precise.
> >>
> >
> > No, the penberg tree did include your patch on slub/partial head.
> > Actually PCP won't take that path, so, there is no need for your patch.
> > I daft a patch to remove some unused code in __slab_free, that related
> > this, and will send it out later.
> 
> Which patch is that? Please send me it to penberg@cs.helsinki.fi as
> @kernel.org email forward isn't working.


Ops, this thread mentioned 2 patches,
1, shaohua's bug fixing patch, that already in your tree as 'slub/urgent
head', if my memory service me right.

2, [PATCH] slub Discard slab page only when node partials > minimum
setting, that is the following. 

----------
From: Alex Shi <alex.shi@intel.com>
Date: Tue, 6 Sep 2011 14:46:01 +0800
Subject: [PATCH ] Discard slab page when node partial > mininum partial number

Discarding slab should be done when node partial > min_partial.
Otherwise, node partial slab may eat up all memory.

Signed-off-by: Alex Shi <alex.shi@intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
---
 mm/slub.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 1348c09..492beab 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1953,7 +1953,7 @@ static void unfreeze_partials(struct kmem_cache *s)
 
 			new.frozen = 0;
 
-			if (!new.inuse && (!n || n->nr_partial < s->min_partial))
+			if (!new.inuse && (!n || n->nr_partial > s->min_partial))
 				m = M_FREE;
 			else {
 				struct kmem_cache_node *n2 = get_node(s,
-- 
1.7.0