Security: smack: replace kzalloc with kmem_cache for inode_smack (1a5b472b) · Commits · 戴 / test

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 <rohit.kr@samsung.com>

security/smack/smack_lsm.c

+10 −3

Original line number	Diff line number	Diff line
		@@ -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");

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