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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2016-05-20 02:13:03 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-20 04:12:14 +0200 |
| commit | 8604d9e534a3e662600e288bcfd1a5acd2763d28 (patch) | |
| tree | 5a18f26f677a786414bb85984bc3dd876162ff8a /mm/memory_hotplug.c | |
| parent | arch: fix has_transparent_hugepage() (diff) | |
| download | linux-8604d9e534a3e662600e288bcfd1a5acd2763d28.tar.xz linux-8604d9e534a3e662600e288bcfd1a5acd2763d28.zip | |
memory_hotplug: introduce CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE
This patchset continues the work I started with commit 31bc3858ea3e
("memory-hotplug: add automatic onlining policy for the newly added
memory").
Initially I was going to stop there and bring the policy setting logic
to userspace. I met two issues on this way:
1) It is possible to have memory hotplugged at boot (e.g. with QEMU).
These blocks stay offlined if we turn the onlining policy on by
userspace.
2) My attempt to bring this policy setting to systemd failed, systemd
maintainers suggest to change the default in kernel or ... to use
tmpfiles.d to alter the policy (which looks like a hack to me):
https://github.com/systemd/systemd/pull/2938
Here I suggest to add a config option to set the default value for the
policy and a kernel command line parameter to make the override.
This patch (of 2):
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.
[akpm@linux-foundation.org: tweak Kconfig text]
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Lennart Poettering <lennart@poettering.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index b21d8895ea41..fcafbfcff044 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) |