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authorOscar Salvador2018-10-26 15:07:34 -0700
committerLinus Torvalds2018-10-26 16:26:33 -0700
commit8efe33f40f3e69ac6069ed46666d2d527ddc2c04 (patch)
tree98625f1326f116dd287dbc4cdd56c24329245e42
parentcf01f6f5e398a74f00fa9ac490ec98c12e63e4b1 (diff)
mm/memory_hotplug.c: simplify node_states_check_changes_online
While looking at node_states_check_changes_online, I stumbled upon some confusing things. Right after entering the function, we find this: if (N_MEMORY == N_NORMAL_MEMORY) zone_last = ZONE_MOVABLE; This is wrong. N_MEMORY cannot really be equal to N_NORMAL_MEMORY. My guess is that this wanted to be something like: if (N_NORMAL_MEMORY == N_HIGH_MEMORY) to check if we have CONFIG_HIGHMEM. Later on, in the CONFIG_HIGHMEM block, we have: if (N_MEMORY == N_HIGH_MEMORY) zone_last = ZONE_MOVABLE; Again, this is wrong, and will never be evaluated to true. Besides removing these wrong if statements, I simplified the function a bit. [osalvador@suse.de: address feedback from Pavel] Link: http://lkml.kernel.org/r/20180921132634.10103-4-osalvador@techadventures.net Link: http://lkml.kernel.org/r/20180919100819.25518-5-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: Michal Hocko <mhocko@suse.com> Cc: <yasu.isimatu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/memory_hotplug.c57
1 files changed, 7 insertions, 50 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 561c44761f95..eadd149eb7bc 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -687,62 +687,19 @@ static void node_states_check_changes_online(unsigned long nr_pages,
struct zone *zone, struct memory_notify *arg)
{
int nid = zone_to_nid(zone);
- enum zone_type zone_last = ZONE_NORMAL;
- /*
- * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY]
- * contains nodes which have zones of 0...ZONE_NORMAL,
- * set zone_last to ZONE_NORMAL.
- *
- * If we don't have HIGHMEM nor movable node,
- * node_states[N_NORMAL_MEMORY] contains nodes which have zones of
- * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE.
- */
- if (N_MEMORY == N_NORMAL_MEMORY)
- zone_last = ZONE_MOVABLE;
+ arg->status_change_nid = -1;
+ arg->status_change_nid_normal = -1;
+ arg->status_change_nid_high = -1;
- /*
- * if the memory to be online is in a zone of 0...zone_last, and
- * the zones of 0...zone_last don't have memory before online, we will
- * need to set the node to node_states[N_NORMAL_MEMORY] after
- * the memory is online.
- */
- if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY))
+ if (!node_state(nid, N_MEMORY))
+ arg->status_change_nid = nid;
+ if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY))
arg->status_change_nid_normal = nid;
- else
- arg->status_change_nid_normal = -1;
-
#ifdef CONFIG_HIGHMEM
- /*
- * If we have movable node, node_states[N_HIGH_MEMORY]
- * contains nodes which have zones of 0...ZONE_HIGHMEM,
- * set zone_last to ZONE_HIGHMEM.
- *
- * If we don't have movable node, node_states[N_NORMAL_MEMORY]
- * contains nodes which have zones of 0...ZONE_MOVABLE,
- * set zone_last to ZONE_MOVABLE.
- */
- zone_last = ZONE_HIGHMEM;
- if (N_MEMORY == N_HIGH_MEMORY)
- zone_last = ZONE_MOVABLE;
-
- if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY))
+ if (zone_idx(zone) <= N_HIGH_MEMORY && !node_state(nid, N_HIGH_MEMORY))
arg->status_change_nid_high = nid;
- else
- arg->status_change_nid_high = -1;
-#else
- arg->status_change_nid_high = arg->status_change_nid_normal;
#endif
-
- /*
- * if the node don't have memory befor online, we will need to
- * set the node to node_states[N_MEMORY] after the memory
- * is online.
- */
- if (!node_state(nid, N_MEMORY))
- arg->status_change_nid = nid;
- else
- arg->status_change_nid = -1;
}
static void node_states_set_node(int node, struct memory_notify *arg)