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Commit 1a5b472b authored by Rohit's avatar Rohit Committed by Casey Schaufler
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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: default avatarRohit <rohit.kr@samsung.com>
parent 6c892df2

security/smack/smack_lsm.c

+10 −3
Original line number Original line Diff line number Diff line
@@ -53,6 +53,7 @@ 
#define SMK_SENDING	2

#define SMK_SENDING	2





LIST_HEAD(smk_ipv6_port_list);

LIST_HEAD(smk_ipv6_port_list);

static struct kmem_cache *smack_inode_cache;





#ifdef CONFIG_SECURITY_SMACK_BRINGUP

#ifdef CONFIG_SECURITY_SMACK_BRINGUP

static void smk_bu_mode(int mode, char *s)

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;

	struct inode_smack *isp;





	isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS);

	isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS);

	if (isp == NULL)

	if (isp == NULL)

		return 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)

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;

	inode->i_security = NULL;

}

}
@@ -4265,10 +4266,16 @@ static __init int smack_init(void) 
	if (!security_module_enable(&smack_ops))

	if (!security_module_enable(&smack_ops))

		return 0;

		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,

	tsp = new_task_smack(&smack_known_floor, &smack_known_floor,

				GFP_KERNEL);

				GFP_KERNEL);

	if (tsp == NULL)

	if (tsp == NULL) {

		kmem_cache_destroy(smack_inode_cache);

		return -ENOMEM;

		return -ENOMEM;

	}





	printk(KERN_INFO "Smack:  Initializing.\n");

	printk(KERN_INFO "Smack:  Initializing.\n");