Messages in this thread | | | Date | Fri, 31 Oct 2014 14:32:35 -0700 | From | Casey Schaufler <> | Subject | Re: [PATCH v2] Security: smack: replace kzalloc with kmem_cache for inode_smack |
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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 <rohit.kr@samsung.com>
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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