From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751955AbbJEGBI (ORCPT ); Mon, 5 Oct 2015 02:01:08 -0400 Received: from LGEAMRELO13.lge.com ([156.147.23.53]:46224 "EHLO lgeamrelo13.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751634AbbJEGBG (ORCPT ); Mon, 5 Oct 2015 02:01:06 -0400 X-Original-SENDERIP: 156.147.1.125 X-Original-MAILFROM: sangwoo2.park@lge.com X-Original-SENDERIP: 165.244.98.150 X-Original-MAILFROM: sangwoo2.park@lge.com X-Original-SENDERIP: 165.243.139.167 X-Original-MAILFROM: sangwoo2.park@lge.com From: Sangwoo To: paul@paul-moore.com, sds@tycho.nsa.gov, eparis@parisplace.org, james.l.morris@oracle.com, serge@hallyn.com CC: selinux@tycho.nsa.gov, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Sangwoo Subject: [PATCH] security: selinux: Use a kmem_cache for allocation struct file_security_struct Date: Mon, 5 Oct 2015 14:45:41 +0900 Message-ID: <1444023941-6482-1-git-send-email-sangwoo2.park@lge.com> X-Mailer: git-send-email 1.7.9.5 X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB05/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2015/10/05 14:46:04, Serialize by Router on LGEKRMHUB05/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2015/10/05 14:46:04, Serialize complete at 2015/10/05 14:46:04 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- security/selinux/hooks.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 3f8d567..c20e082 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)); -- 1.7.9.5