From 1a5b472bde752783e0a31b59c61c9ff5b37a0983 Mon Sep 17 00:00:00 2001 From: Rohit Date: Wed, 15 Oct 2014 17:40:41 +0530 Subject: [PATCH] Security: smack: replace kzalloc with kmem_cache for inode_smack The patch use kmem_cache to allocate/free inode_smack since they are alloced in high volumes making it a perfect case for kmem_cache. As per analysis, 24 bytes of memory is wasted per allocation due to internal fragmentation. With kmem_cache, this can be avoided. Accounting of memory allocation is below : total slack net count-alloc/free caller Before (with kzalloc) 1919872 719952 1919872 29998/0 new_inode_smack+0x14 After (with kmem_cache) 1201680 0 1201680 30042/0 new_inode_smack+0x18 >From above data, we found that 719952 bytes(~700 KB) of memory is saved on allocation of 29998 smack inodes. Signed-off-by: Rohit --- security/smack/smack_lsm.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 93dc876734a4..2717cdd7872c 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -53,6 +53,7 @@ #define SMK_SENDING 2 LIST_HEAD(smk_ipv6_port_list); +static struct kmem_cache *smack_inode_cache; #ifdef CONFIG_SECURITY_SMACK_BRINGUP static void smk_bu_mode(int mode, char *s) @@ -240,7 +241,7 @@ struct inode_smack *new_inode_smack(struct smack_known *skp) { struct inode_smack *isp; - isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS); + isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS); if (isp == NULL) return NULL; @@ -767,7 +768,7 @@ static int smack_inode_alloc_security(struct inode *inode) */ static void smack_inode_free_security(struct inode *inode) { - kfree(inode->i_security); + kmem_cache_free(smack_inode_cache, inode->i_security); inode->i_security = NULL; } @@ -4265,10 +4266,16 @@ static __init int smack_init(void) if (!security_module_enable(&smack_ops)) return 0; + smack_inode_cache = KMEM_CACHE(inode_smack, 0); + if (!smack_inode_cache) + return -ENOMEM; + tsp = new_task_smack(&smack_known_floor, &smack_known_floor, GFP_KERNEL); - if (tsp == NULL) + if (tsp == NULL) { + kmem_cache_destroy(smack_inode_cache); return -ENOMEM; + } printk(KERN_INFO "Smack: Initializing.\n"); -- 2.39.5