linux-kernel - [PATCH v3 1/5] mm/slab: Fix drain freelist excessively

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Thu,  4 Jul 2013 08:33:22 +0800
From:	Wanpeng Li <liwanp@...ux.vnet.ibm.com>
To:	Pekka Enberg <penberg@...nel.org>,
	Christoph Lameter <cl@...ux-foundation.org>,
	Matt Mackall <mpm@...enic.com>
Cc:	Glauber Costa <glommer@...allels.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Joonsoo Kim <js1304@...il.com>,
	David Rientjes <rientjes@...gle.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Wanpeng Li <liwanp@...ux.vnet.ibm.com>
Subject: [PATCH v3 1/5] mm/slab: Fix drain freelist excessively

Changelog:
 v1 -> v2:
  * Fix the callers that pass # of objects. Make sure they pass # of slabs.
 v2 -> v3:
  * introduce helper function slabs_tofree 

The drain_freelist is called to drain slabs_free lists for cache reap,
cache shrink, memory hotplug callback etc. The tofree parameter should
be the number of slab to free instead of the number of slab objects to
free.

This patch fix the callers that pass # of objects. Make sure they pass #
of slabs.

Signed-off-by: Wanpeng Li <liwanp@...ux.vnet.ibm.com>
---
 mm/slab.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index e6122b2..3002771 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1180,6 +1180,12 @@ static int init_cache_node_node(int node)
 	return 0;
 }
 
+static inline int slabs_tofree(struct kmem_cache *cachep,
+						struct kmem_cache_node *n)
+{
+	return (n->free_objects + cachep->num - 1) / cachep->num;
+}
+
 static void cpuup_canceled(long cpu)
 {
 	struct kmem_cache *cachep;
@@ -1241,7 +1247,7 @@ free_array_cache:
 		n = cachep->node[node];
 		if (!n)
 			continue;
-		drain_freelist(cachep, n, n->free_objects);
+		drain_freelist(cachep, n, slabs_tofree(cachep, n));
 	}
 }
 
@@ -1408,7 +1414,7 @@ static int __meminit drain_cache_node_node(int node)
 		if (!n)
 			continue;
 
-		drain_freelist(cachep, n, n->free_objects);
+		drain_freelist(cachep, n, slabs_tofree(cachep, n));
 
 		if (!list_empty(&n->slabs_full) ||
 		    !list_empty(&n->slabs_partial)) {
@@ -2532,7 +2538,7 @@ static int __cache_shrink(struct kmem_cache *cachep)
 		if (!n)
 			continue;
 
-		drain_freelist(cachep, n, n->free_objects);
+		drain_freelist(cachep, n, slabs_tofree(cachep, n));
 
 		ret += !list_empty(&n->slabs_full) ||
 			!list_empty(&n->slabs_partial);
-- 
1.8.1.2

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