Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752743AbYLSETw (ORCPT ); Thu, 18 Dec 2008 23:19:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752598AbYLSETH (ORCPT ); Thu, 18 Dec 2008 23:19:07 -0500 Received: from ti-out-0910.google.com ([209.85.142.187]:44365 "EHLO ti-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752578AbYLSETG (ORCPT ); Thu, 18 Dec 2008 23:19:06 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=KjPU49x6QTHqSzPnq1hKFsqPKmyF6hOwtfbXp8rWAoxBlZ+pRy1pD4emUBrUiuwBHs uQqkPku+Lob5fnWMhNOWuPUqx30JIOkhryRzLxZxtnI1ZhYHmsbKYfOdZUhPvI0jKpr4 WIOn9XE9Iffmw2oryMwXjofrbHxnAlkLfyito= From: crquan@gmail.com To: dm-devel@redhat.com Cc: Alasdair G Kergon , linux-kernel@vger.kernel.org Subject: [PATCH 2/3] dm-target: use pointer reference instead of making a copy Date: Fri, 19 Dec 2008 12:19:44 +0800 Message-Id: <1229660385-17153-3-git-send-email-crquan@gmail.com> X-Mailer: git-send-email 1.6.0.4 In-Reply-To: <1229660385-17153-2-git-send-email-crquan@gmail.com> References: <1229660385-17153-1-git-send-email-crquan@gmail.com> <1229660385-17153-2-git-send-email-crquan@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2679 Lines: 98 From: Cheng Renquan The tt_internal always use target_type read-only, so there's no need to making a copy, just a pointer reference is good, this could save (sizeof(target_type) - sizeof(pointer)) bytes memory per target_type. - ti->tt = *t; + ti->tt = t; Signed-off-by: Cheng Renquan --- drivers/md/dm-target.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c index 018df35..a713c7f 100644 --- a/drivers/md/dm-target.c +++ b/drivers/md/dm-target.c @@ -15,7 +15,7 @@ #define DM_MSG_PREFIX "target" struct tt_internal { - struct target_type tt; + struct target_type *tt; struct list_head list; }; @@ -30,7 +30,7 @@ static inline struct tt_internal *__find_target_type(const char *name) struct tt_internal *ti; list_for_each_entry (ti, &_targets, list) - if (!strcmp(name, ti->tt.name)) + if (!strcmp(name, ti->tt->name)) return ti; return NULL; @@ -43,7 +43,7 @@ static struct tt_internal *get_target_type(const char *name) down_read(&_lock); ti = __find_target_type(name); - if (ti && !try_module_get(ti->tt.module)) + if (ti && !try_module_get(ti->tt->module)) ti = NULL; up_read(&_lock); @@ -64,7 +64,7 @@ struct target_type *dm_get_target_type(const char *name) ti = get_target_type(name); } - return ti ? &ti->tt : NULL; + return ti ? ti->tt : NULL; } void dm_put_target_type(struct target_type *t) @@ -72,7 +72,7 @@ void dm_put_target_type(struct target_type *t) struct tt_internal *ti = (struct tt_internal *) t; down_read(&_lock); - module_put(ti->tt.module); + module_put(ti->tt->module); up_read(&_lock); return; @@ -83,7 +83,7 @@ static struct tt_internal *alloc_target(struct target_type *t) struct tt_internal *ti = kzalloc(sizeof(*ti), GFP_KERNEL); if (ti) - ti->tt = *t; + ti->tt = t; return ti; } @@ -96,7 +96,7 @@ int dm_target_iterate(void (*iter_func)(struct target_type *tt, down_read(&_lock); list_for_each_entry (ti, &_targets, list) - iter_func(&ti->tt, param); + iter_func(ti->tt, param); up_read(&_lock); return 0; @@ -132,7 +132,7 @@ int dm_unregister_target(struct target_type *t) return -EINVAL; } - if (ti->tt.module && module_refcount(ti->tt.module)) { + if (ti->tt->module && module_refcount(ti->tt->module)) { up_write(&_lock); return -ETXTBSY; } -- 1.6.0.2.GIT -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/