From: Sangwoo Date: Wed, 21 Oct 2015 21:44:30 +0000 (-0400) Subject: selinux: Use a kmem_cache for allocation struct file_security_struct X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=63205654c0e05e5ffa1c6eef2fbef21dcabd2185;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git selinux: Use a kmem_cache for allocation struct file_security_struct The size of struct file_security_struct is 16byte at my setup. But, the real allocation size for per each file_security_struct is 64bytes in my setup that kmalloc min size is 64bytes because ARCH_DMA_MINALIGN is 64. This allocation is called every times at file allocation(alloc_file()). So, the total slack memory size(allocated size - request size) is increased exponentially. E.g) Min Kmalloc Size : 64bytes, Unit : bytes Allocated Size | Request Size | Slack Size | Allocation Count --------------------------------------------------------------- 770048 | 192512 | 577536 | 12032 At the result, this change reduce memory usage 42bytes per each file_security_struct Signed-off-by: Sangwoo Acked-by: Stephen Smalley [PM: removed extra subject prefix] Signed-off-by: Paul Moore --- diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 799d15aa35f9..305399225010 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -126,6 +126,7 @@ int selinux_enabled = 1; #endif static struct kmem_cache *sel_inode_cache; +static struct kmem_cache *file_security_cache; /** * selinux_secmark_enabled - Check to see if SECMARK is currently enabled @@ -287,7 +288,7 @@ static int file_alloc_security(struct file *file) struct file_security_struct *fsec; u32 sid = current_sid(); - fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); + fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL); if (!fsec) return -ENOMEM; @@ -302,7 +303,7 @@ static void file_free_security(struct file *file) { struct file_security_struct *fsec = file->f_security; file->f_security = NULL; - kfree(fsec); + kmem_cache_free(file_security_cache, fsec); } static int superblock_alloc_security(struct super_block *sb) @@ -6086,6 +6087,9 @@ static __init int selinux_init(void) sel_inode_cache = kmem_cache_create("selinux_inode_security", sizeof(struct inode_security_struct), 0, SLAB_PANIC, NULL); + file_security_cache = kmem_cache_create("selinux_file_security", + sizeof(struct file_security_struct), + 0, SLAB_PANIC, NULL); avc_init(); security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));