From: James Morris Date: Wed, 22 Mar 2006 08:09:22 +0000 (-0800) Subject: [PATCH] SELinux: add slab cache for inode security struct X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=7cae7e26f245151b9ccad868bf2edf8c8048d307;p=openwrt%2Fstaging%2Fblogic.git [PATCH] SELinux: add slab cache for inode security struct Add a slab cache for the SELinux inode security struct, one of which is allocated for every inode instantiated by the system. The memory savings are considerable. On 64-bit, instead of the size-128 cache, we have a slab object of 96 bytes, saving 32 bytes per object. After booting, I see about 4000 of these and then about 17,000 after a kernel compile. With this patch, we save around 530KB of kernel memory in the latter case. On 32-bit, the savings are about half of this. Signed-off-by: James Morris Acked-by: Stephen Smalley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index bdd0b32f0104..ccaf988f3729 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -117,6 +117,8 @@ static struct security_operations *secondary_ops = NULL; static LIST_HEAD(superblock_security_head); static DEFINE_SPINLOCK(sb_security_lock); +static kmem_cache_t *sel_inode_cache; + /* Allocate and free functions for each kind of security blob. */ static int task_alloc_security(struct task_struct *task) @@ -146,10 +148,11 @@ static int inode_alloc_security(struct inode *inode) struct task_security_struct *tsec = current->security; struct inode_security_struct *isec; - isec = kzalloc(sizeof(struct inode_security_struct), GFP_KERNEL); + isec = kmem_cache_alloc(sel_inode_cache, SLAB_KERNEL); if (!isec) return -ENOMEM; + memset(isec, 0, sizeof(*isec)); init_MUTEX(&isec->sem); INIT_LIST_HEAD(&isec->list); isec->inode = inode; @@ -172,7 +175,7 @@ static void inode_free_security(struct inode *inode) spin_unlock(&sbsec->isec_lock); inode->i_security = NULL; - kfree(isec); + kmem_cache_free(sel_inode_cache, isec); } static int file_alloc_security(struct file *file) @@ -4406,6 +4409,9 @@ static __init int selinux_init(void) tsec = current->security; tsec->osid = tsec->sid = SECINITSID_KERNEL; + sel_inode_cache = kmem_cache_create("selinux_inode_security", + sizeof(struct inode_security_struct), + 0, SLAB_PANIC, NULL, NULL); avc_init(); original_ops = secondary_ops = security_ops;