From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f42.google.com (mail-qg0-f42.google.com [209.85.192.42]) by kanga.kvack.org (Postfix) with ESMTP id C914E6B007E for ; Wed, 6 Apr 2016 09:45:20 -0400 (EDT) Received: by mail-qg0-f42.google.com with SMTP id f52so36022384qga.3 for ; Wed, 06 Apr 2016 06:45:20 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id 10si2114391qhw.26.2016.04.06.06.45.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 06 Apr 2016 06:45:20 -0700 (PDT) From: Vitaly Kuznetsov Subject: [PATCH 1/2] memory_hotplug: introduce CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE Date: Wed, 6 Apr 2016 15:45:11 +0200 Message-Id: <1459950312-25504-2-git-send-email-vkuznets@redhat.com> In-Reply-To: <1459950312-25504-1-git-send-email-vkuznets@redhat.com> References: <1459950312-25504-1-git-send-email-vkuznets@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , Jonathan Corbet , Dan Williams , "Kirill A. Shutemov" , Mel Gorman , David Vrabel , David Rientjes , Igor Mammedov Introduce config option to set the default value for memory hotplug onlining policy (/sys/devices/system/memory/auto_online_blocks). The reason one would want to turn this option on are to have early onlining for hotpluggable memory available at boot and to not require any userspace actions to make memory hotplug work. Signed-off-by: Vitaly Kuznetsov --- Documentation/memory-hotplug.txt | 9 +++++---- mm/Kconfig | 16 ++++++++++++++++ mm/memory_hotplug.c | 4 ++++ 3 files changed, 25 insertions(+), 4 deletions(-) diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index 443f4b4..0d7cb95 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -261,10 +261,11 @@ it according to the policy which can be read from "auto_online_blocks" file: % cat /sys/devices/system/memory/auto_online_blocks -The default is "offline" which means the newly added memory is not in a -ready-to-use state and you have to "online" the newly added memory blocks -manually. Automatic onlining can be requested by writing "online" to -"auto_online_blocks" file: +The default depends on the CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config +option. If it is disabled the default is "offline" which means the newly added +memory is not in a ready-to-use state and you have to "online" the newly added +memory blocks manually. Automatic onlining can be requested by writing "online" +to "auto_online_blocks" file: % echo online > /sys/devices/system/memory/auto_online_blocks diff --git a/mm/Kconfig b/mm/Kconfig index 989f8f3..4c7dd6e 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -192,6 +192,22 @@ config MEMORY_HOTPLUG_SPARSE def_bool y depends on SPARSEMEM && MEMORY_HOTPLUG +config MEMORY_HOTPLUG_DEFAULT_ONLINE + bool "Online the newly added memory blocks by default" + default n + depends on MEMORY_HOTPLUG + help + This option changes the default policy setting for memory hotplug + onlining policy (/sys/devices/system/memory/auto_online_blocks) which + determines what happens to the newly added memory regions. Policy + setting can always be changed in runtime. + See Documentation/memory-hotplug.txt for more information. + + Say Y here if you want all hot-plugged memory blocks to appear in + 'online' state by default. + Say N here if you want the default policy to keep all hot-plugged + memory blocks in 'offline' state. + config MEMORY_HOTREMOVE bool "Allow for memory hot remove" select MEMORY_ISOLATION diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index aa34431..072e0a1 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -78,7 +78,11 @@ static struct { #define memhp_lock_acquire() lock_map_acquire(&mem_hotplug.dep_map) #define memhp_lock_release() lock_map_release(&mem_hotplug.dep_map) +#ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE bool memhp_auto_online; +#else +bool memhp_auto_online = true; +#endif EXPORT_SYMBOL_GPL(memhp_auto_online); void get_online_mems(void) -- 2.5.5 -- 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