On 10/15/2014 5:10 AM, Rohit wrote:
> 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 <[email protected]>
Applied to git://git.gitorious.org/smack-next/kernel.git#smack-for-3.19
> ---
> Added static in kmem_cache object declaration noted by Andrew Morton <akpm@
> linux-foundation.org> . Also updated commit message.
> 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 d515ec2..15d985c 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;
> }
>
> @@ -4264,10 +4265,16 @@ 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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