Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753916AbdCPOh3 (ORCPT ); Thu, 16 Mar 2017 10:37:29 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33528 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753875AbdCPOhZ (ORCPT ); Thu, 16 Mar 2017 10:37:25 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Michal Hocko , Vladimir Davydov , Andrew Morton , Linus Torvalds Subject: [PATCH 4.4 13/35] mm: memcontrol: avoid unused function warning Date: Thu, 16 Mar 2017 23:29:32 +0900 Message-Id: <20170316142907.601154068@linuxfoundation.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170316142906.685052998@linuxfoundation.org> References: <20170316142906.685052998@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2555 Lines: 83 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann commit 358c07fcc3b60ab08d77f1684de8bd81bcf49a1a upstream. A bugfix in v4.8-rc2 introduced a harmless warning when CONFIG_MEMCG_SWAP is disabled but CONFIG_MEMCG is enabled: mm/memcontrol.c:4085:27: error: 'mem_cgroup_id_get_online' defined but not used [-Werror=unused-function] static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) This moves the function inside of the #ifdef block that hides the calling function, to avoid the warning. Fixes: 1f47b61fb407 ("mm: memcontrol: fix swap counter leak on swapout from offline cgroup") Link: http://lkml.kernel.org/r/20160824113733.2776701-1-arnd@arndb.de Signed-off-by: Arnd Bergmann Acked-by: Michal Hocko Acked-by: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/memcontrol.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4150,24 +4150,6 @@ static void mem_cgroup_id_get_many(struc atomic_add(n, &memcg->id.ref); } -static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) -{ - while (!atomic_inc_not_zero(&memcg->id.ref)) { - /* - * The root cgroup cannot be destroyed, so it's refcount must - * always be >= 1. - */ - if (WARN_ON_ONCE(memcg == root_mem_cgroup)) { - VM_BUG_ON(1); - break; - } - memcg = parent_mem_cgroup(memcg); - if (!memcg) - memcg = root_mem_cgroup; - } - return memcg; -} - static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n) { if (atomic_sub_and_test(n, &memcg->id.ref)) { @@ -5751,6 +5733,24 @@ static int __init mem_cgroup_init(void) subsys_initcall(mem_cgroup_init); #ifdef CONFIG_MEMCG_SWAP +static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) +{ + while (!atomic_inc_not_zero(&memcg->id.ref)) { + /* + * The root cgroup cannot be destroyed, so it's refcount must + * always be >= 1. + */ + if (WARN_ON_ONCE(memcg == root_mem_cgroup)) { + VM_BUG_ON(1); + break; + } + memcg = parent_mem_cgroup(memcg); + if (!memcg) + memcg = root_mem_cgroup; + } + return memcg; +} + /** * mem_cgroup_swapout - transfer a memsw charge to swap * @page: page whose memsw charge to transfer