From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753432AbbDAOaq (ORCPT ); Wed, 1 Apr 2015 10:30:46 -0400 Received: from mx2.parallels.com ([199.115.105.18]:34077 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753269AbbDAOan (ORCPT ); Wed, 1 Apr 2015 10:30:43 -0400 From: Vladimir Davydov To: Andrew Morton CC: , , Subject: [PATCH] Documentation/memcg: update memcg/kmem status Date: Wed, 1 Apr 2015 17:30:36 +0300 Message-ID: <1427898636-4505-1-git-send-email-vdavydov@parallels.com> X-Mailer: git-send-email 1.7.10.4 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 Memcg/kmem reclaim support has been finally merged. Reflect this in the documentation. Signed-off-by: Vladimir Davydov --- Documentation/cgroups/memory.txt | 8 +++----- init/Kconfig | 6 ------ 2 files changed, 3 insertions(+), 11 deletions(-) diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index a22df3ad35ff..f456b4315e86 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -275,11 +275,6 @@ When oom event notifier is registered, event will be delivered. 2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM) -WARNING: Current implementation lacks reclaim support. That means allocation - attempts will fail when close to the limit even if there are plenty of - kmem available for reclaim. That makes this option unusable in real - life so DO NOT SELECT IT unless for development purposes. - With the Kernel memory extension, the Memory Controller is able to limit the amount of kernel memory used by the system. Kernel memory is fundamentally different than user memory, since it can't be swapped out, which makes it @@ -345,6 +340,9 @@ set: In this case, the admin could set up K so that the sum of all groups is never greater than the total memory, and freely set U at the cost of his QoS. + WARNING: In the current implementation, memory reclaim will NOT be + triggered for a cgroup when it hits K while staying below U, which makes + this setup impractical. U != 0, K >= U: Since kmem charges will also be fed to the user counter and reclaim will be diff --git a/init/Kconfig b/init/Kconfig index 7766b500f679..caffca37ccb7 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1059,12 +1059,6 @@ config MEMCG_KMEM the kmem extension can use it to guarantee that no group of processes will ever exhaust kernel resources alone. - WARNING: Current implementation lacks reclaim support. That means - allocation attempts will fail when close to the limit even if there - are plenty of kmem available for reclaim. That makes this option - unusable in real life so DO NOT SELECT IT unless for development - purposes. - config CGROUP_HUGETLB bool "HugeTLB Resource Controller for Control Groups" depends on HUGETLB_PAGE -- 1.7.10.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: [PATCH] Documentation/memcg: update memcg/kmem status Date: Wed, 1 Apr 2015 17:30:36 +0300 Message-ID: <1427898636-4505-1-git-send-email-vdavydov@parallels.com> Mime-Version: 1.0 Return-path: Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Morton Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Memcg/kmem reclaim support has been finally merged. Reflect this in the documentation. Signed-off-by: Vladimir Davydov --- Documentation/cgroups/memory.txt | 8 +++----- init/Kconfig | 6 ------ 2 files changed, 3 insertions(+), 11 deletions(-) diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index a22df3ad35ff..f456b4315e86 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -275,11 +275,6 @@ When oom event notifier is registered, event will be delivered. 2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM) -WARNING: Current implementation lacks reclaim support. That means allocation - attempts will fail when close to the limit even if there are plenty of - kmem available for reclaim. That makes this option unusable in real - life so DO NOT SELECT IT unless for development purposes. - With the Kernel memory extension, the Memory Controller is able to limit the amount of kernel memory used by the system. Kernel memory is fundamentally different than user memory, since it can't be swapped out, which makes it @@ -345,6 +340,9 @@ set: In this case, the admin could set up K so that the sum of all groups is never greater than the total memory, and freely set U at the cost of his QoS. + WARNING: In the current implementation, memory reclaim will NOT be + triggered for a cgroup when it hits K while staying below U, which makes + this setup impractical. U != 0, K >= U: Since kmem charges will also be fed to the user counter and reclaim will be diff --git a/init/Kconfig b/init/Kconfig index 7766b500f679..caffca37ccb7 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1059,12 +1059,6 @@ config MEMCG_KMEM the kmem extension can use it to guarantee that no group of processes will ever exhaust kernel resources alone. - WARNING: Current implementation lacks reclaim support. That means - allocation attempts will fail when close to the limit even if there - are plenty of kmem available for reclaim. That makes this option - unusable in real life so DO NOT SELECT IT unless for development - purposes. - config CGROUP_HUGETLB bool "HugeTLB Resource Controller for Control Groups" depends on HUGETLB_PAGE -- 1.7.10.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org