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mm, memory_hotplug: drop CONFIG_MOVABLE_NODE 

Commit 20b2f52b73 ("numa: add CONFIG_MOVABLE_NODE for
movable-dedicated node") has introduced CONFIG_MOVABLE_NODE without a
good explanation on why it is actually useful.

It makes a lot of sense to make movable node semantic opt in but we
already have that because the feature has to be explicitly enabled on
the kernel command line.  A config option on top only makes the
configuration space larger without a good reason.  It also adds an
additional ifdefery that pollutes the code.

Just drop the config option and make it de-facto always enabled.  This
shouldn't introduce any change to the semantic.

Link: http://lkml.kernel.org/r/20170529114141.536-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kani Toshimitsu <toshi.kani@hpe.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michal Hocko 2017-07-06 15:41:02 -07:00 committed by Linus Torvalds
parent 57c0a17238
commit f70029bbaa
8 changed files with 5 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
Documentation/admin-guide/kernel-parameters.txt
View File

@ -2303,8 +2303,11 @@
that the amount of memory usable for all allocations
is not too small.
movable_node [KNL] Boot-time switch to enable the effects
of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details.
movable_node [KNL] Boot-time switch to make hotplugable memory
NUMA nodes to be movable. This means that the memory
of such nodes will be usable only for movable
allocations which rules out almost all kernel
allocations. Use with caution!
MTD_Partition= [MTD]
Format: <name>,<region-number>,<size>,<offset>

4
drivers/base/node.c
View File

@ -639,9 +639,7 @@ static struct node_attr node_state_attr[] = {
#ifdef CONFIG_HIGHMEM
[N_HIGH_MEMORY] = _NODE_ATTR(has_high_memory, N_HIGH_MEMORY),
#endif
#ifdef CONFIG_MOVABLE_NODE
[N_MEMORY] = _NODE_ATTR(has_memory, N_MEMORY),
#endif
[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
};
@ -652,9 +650,7 @@ static struct attribute *node_state_attrs[] = {
#ifdef CONFIG_HIGHMEM
&node_state_attr[N_HIGH_MEMORY].attr.attr,
#endif
#ifdef CONFIG_MOVABLE_NODE
&node_state_attr[N_MEMORY].attr.attr,
#endif
&node_state_attr[N_CPU].attr.attr,
NULL
};

18
include/linux/memblock.h
View File

@ -57,10 +57,8 @@ struct memblock {
extern struct memblock memblock;
extern int memblock_debug;
#ifdef CONFIG_MOVABLE_NODE
/* If movable_node boot option specified */
extern bool movable_node_enabled;
#endif /* CONFIG_MOVABLE_NODE */
#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
#define __init_memblock __meminit
@ -169,7 +167,6 @@ void __next_reserved_mem_region(u64 *idx, phys_addr_t *out_start,
i != (u64)ULLONG_MAX; \
__next_reserved_mem_region(&i, p_start, p_end))
#ifdef CONFIG_MOVABLE_NODE
static inline bool memblock_is_hotpluggable(struct memblock_region *m)
{
return m->flags & MEMBLOCK_HOTPLUG;
@ -179,16 +176,6 @@ static inline bool __init_memblock movable_node_is_enabled(void)
{
return movable_node_enabled;
}
#else
static inline bool memblock_is_hotpluggable(struct memblock_region *m)
{
return false;
}
static inline bool movable_node_is_enabled(void)
{
return false;
}
#endif
static inline bool memblock_is_mirror(struct memblock_region *m)
{
@ -296,7 +283,6 @@ phys_addr_t memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
phys_addr_t memblock_alloc(phys_addr_t size, phys_addr_t align);
#ifdef CONFIG_MOVABLE_NODE
/*
* Set the allocation direction to bottom-up or top-down.
*/
@ -314,10 +300,6 @@ static inline bool memblock_bottom_up(void)
{
return memblock.bottom_up;
}
#else
static inline void __init memblock_set_bottom_up(bool enable) {}
static inline bool memblock_bottom_up(void) { return false; }
#endif
/* Flags for memblock_alloc_base() amd __memblock_alloc_base() */
#define MEMBLOCK_ALLOC_ANYWHERE (~(phys_addr_t)0)

4
include/linux/nodemask.h
View File

@ -387,11 +387,7 @@ enum node_states {
#else
N_HIGH_MEMORY = N_NORMAL_MEMORY,
#endif
#ifdef CONFIG_MOVABLE_NODE
N_MEMORY, /* The node has memory(regular, high, movable) */
#else
N_MEMORY = N_HIGH_MEMORY,
#endif
N_CPU, /* The node has one or more cpus */
NR_NODE_STATES
};

26
mm/Kconfig
View File

@ -149,32 +149,6 @@ config NO_BOOTMEM
config MEMORY_ISOLATION
bool
config MOVABLE_NODE
bool "Enable to assign a node which has only movable memory"
depends on HAVE_MEMBLOCK
depends on NO_BOOTMEM
depends on X86_64 || OF_EARLY_FLATTREE || MEMORY_HOTPLUG
depends on NUMA
default n
help
Allow a node to have only movable memory. Pages used by the kernel,
such as direct mapping pages cannot be migrated. So the corresponding
memory device cannot be hotplugged. This option allows the following
two things:
- When the system is booting, node full of hotpluggable memory can
be arranged to have only movable memory so that the whole node can
be hot-removed. (need movable_node boot option specified).
- After the system is up, the option allows users to online all the
memory of a node as movable memory so that the whole node can be
hot-removed.
Users who don't use the memory hotplug feature are fine with this
option on since they don't specify movable_node boot option or they
don't online memory as movable.
Say Y here if you want to hotplug a whole node.
Say N here if you want kernel to use memory on all nodes evenly.
#
# Only be set on architectures that have completely implemented memory hotplug
# feature. If you are not sure, don't touch it.

2
mm/memblock.c
View File

@ -54,9 +54,7 @@ struct memblock memblock __initdata_memblock = {
};
int memblock_debug __initdata_memblock;
#ifdef CONFIG_MOVABLE_NODE
bool movable_node_enabled __initdata_memblock = false;
#endif
static bool system_has_some_mirror __initdata_memblock = false;
static int memblock_can_resize __initdata_memblock;
static int memblock_memory_in_slab __initdata_memblock = 0;

4
mm/memory_hotplug.c
View File

@ -1572,11 +1572,7 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
static int __init cmdline_parse_movable_node(char *p)
{
#ifdef CONFIG_MOVABLE_NODE
movable_node_enabled = true;
#else
pr_warn("movable_node option not supported\n");
#endif
return 0;
}
early_param("movable_node", cmdline_parse_movable_node);

2
mm/page_alloc.c
View File

@ -113,9 +113,7 @@ nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
#ifdef CONFIG_HIGHMEM
[N_HIGH_MEMORY] = { { [0] = 1UL } },
#endif
#ifdef CONFIG_MOVABLE_NODE
[N_MEMORY] = { { [0] = 1UL } },
#endif
[N_CPU] = { { [0] = 1UL } },
#endif /* NUMA */
};