On ARM, sizeof(struct smack_master_list) == 12. Allocation by kmalloc() uses a
32-byte-long chunk to allocate 12 bytes. Just ask ksize(). It means that 63%
of memory is simply wasted for padding bytes.
The problem is fixed in this patch by using kmem_cache. The cache allocates
struct smack_master_list using 16-byte-long chunks according to ksize(). This
reduces amount of used memory by 50%.
Signed-off-by: Tomasz Stanislawski <t.stanisl...@samsung.com>
---
security/smack/smack.h | 7 +++++++
security/smack/smack_lsm.c | 8 ++++++++
security/smack/smackfs.c | 8 ++------
3 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 38ba673..463f818 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -194,6 +194,12 @@ struct smk_audit_info {
struct smack_audit_data sad;
#endif
};
+
+struct smack_master_list {
+ struct list_head list;
+ struct smack_rule *smk_rule;
+};
+
/*
* These functions are in smack_lsm.c
*/
@@ -235,6 +241,7 @@ extern struct list_head smk_netlbladdr_list;
/* Cache for fast and thrifty allocations */
extern struct kmem_cache *smack_rule_cache;
+extern struct kmem_cache *smack_master_list_cache;
extern struct security_operations smack_ops;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 7aa696a..1d4a1b0 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3566,6 +3566,7 @@ static __init void init_smack_known_list(void)
/* KMEM caches for fast and thrifty allocations */
struct kmem_cache *smack_rule_cache;
+struct kmem_cache *smack_master_list_cache;
/**
* smack_init - initialize the smack system
@@ -3584,9 +3585,16 @@ static __init int smack_init(void)
if (!smack_rule_cache)
return -ENOMEM;
+ smack_master_list_cache = KMEM_CACHE(smack_master_list, 0);
+ if (!smack_master_list_cache) {
+ kmem_cache_destroy(smack_rule_cache);
+ return -ENOMEM;
+ }
+
tsp = new_task_smack(smack_known_floor.smk_known,
smack_known_floor.smk_known, GFP_KERNEL);
if (tsp == NULL) {
+ kmem_cache_destroy(smack_master_list_cache);
kmem_cache_destroy(smack_rule_cache);
return -ENOMEM;
}
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 4615242..7ffce7e 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -104,11 +104,6 @@ LIST_HEAD(smk_netlbladdr_list);
* Rule lists are maintained for each label.
* This master list is just for reading /smack/load and /smack/load2.
*/
-struct smack_master_list {
- struct list_head list;
- struct smack_rule *smk_rule;
-};
-
LIST_HEAD(smack_rule_list);
struct smack_parsed_rule {
@@ -233,7 +228,8 @@ static int smk_set_access(struct smack_parsed_rule *srp,
* it needs to get added for reporting.
*/
if (global) {
- smlp = kzalloc(sizeof(*smlp), GFP_KERNEL);
+ smlp = kmem_cache_zalloc(smack_master_list_cache,
+ GFP_KERNEL);
if (smlp != NULL) {
smlp->smk_rule = sp;
list_add_rcu(&smlp->list, &smack_rule_list);
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
