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 <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: David Vrabel <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Lennart Poettering <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Vitaly Kuznetsov 2016-05-19 17:13:06 -07:00 • committed by Linus Torvalds
commit 86dd995d63
2 changed files with 19 additions and 0 deletions

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@ -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

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@ -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();