From 86dd995d63241039e0ad9123f9b424013c611510 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Thu, 19 May 2016 17:13:06 -0700 Subject: [PATCH 1/1] memory_hotplug: introduce memhp_default_state= command line parameter CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE specifies the default value for the memory hotplug onlining policy. Add a command line parameter to make it possible to override the default. It may come handy for debug and testing purposes. Signed-off-by: Vitaly Kuznetsov Cc: Jonathan Corbet Cc: Dan Williams Cc: "Kirill A. Shutemov" Cc: Mel Gorman Cc: David Vrabel Cc: David Rientjes Cc: Igor Mammedov Cc: Lennart Poettering Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 8 ++++++++ mm/memory_hotplug.c | 11 +++++++++++ 2 files changed, 19 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 794403166a8f..2edb27bdc680 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2161,6 +2161,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. [KNL,SH] Allow user to override the default size for per-device physically contiguous DMA buffers. + memhp_default_state=online/offline + [KNL] Set the initial state for the memory hotplug + onlining policy. If not specified, the default value is + set according to the + CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config + option. + See Documentation/memory-hotplug.txt. + memmap=exactmap [KNL,X86] Enable setting of an exact E820 memory map, as specified by the user. Such memmap=exactmap lines can be constructed based on diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index fcafbfcff044..caf2a14c37ad 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -85,6 +85,17 @@ bool memhp_auto_online = true; #endif EXPORT_SYMBOL_GPL(memhp_auto_online); +static int __init setup_memhp_default_state(char *str) +{ + if (!strcmp(str, "online")) + memhp_auto_online = true; + else if (!strcmp(str, "offline")) + memhp_auto_online = false; + + return 1; +} +__setup("memhp_default_state=", setup_memhp_default_state); + void get_online_mems(void) { might_sleep(); -- 2.20.1