[PATCH 2/2] lib/bitmap.c: guard exotic bitmap functions by CONFIG_NUMA

From: Rasmus Villemoes
Date: Fri Mar 29 2019 - 16:54:04 EST


The bitmap_remap, _bitremap, _onto and _fold functions are only used,
via their node_ wrappers, in mm/mempolicy.c, which is only built for
CONFIG_NUMA. The helper bitmap_ord_to_pos used by these functions is
global, but its only external caller is node_random() in lib/nodemask.c,
which is also guarded by CONFIG_NUMA.

For !CONFIG_NUMA:

add/remove: 0/6 grow/shrink: 0/0 up/down: 0/-621 (-621)
Function old new delta
bitmap_pos_to_ord 20 - -20
bitmap_ord_to_pos 70 - -70
bitmap_bitremap 81 - -81
bitmap_fold 113 - -113
bitmap_onto 123 - -123
bitmap_remap 214 - -214
Total: Before=4776, After=4155, chg -13.00%

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
---
lib/bitmap.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 66421f304f7d..3f3b8051f342 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -649,6 +649,7 @@ int bitmap_parselist_user(const char __user *ubuf,
EXPORT_SYMBOL(bitmap_parselist_user);


+#ifdef CONFIG_NUMA
/**
* bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
* @buf: pointer to a bitmap
@@ -952,6 +953,7 @@ void bitmap_fold(unsigned long *dst, const unsigned long *orig,
for_each_set_bit(oldbit, orig, nbits)
set_bit(oldbit % sz, dst);
}
+#endif /* CONFIG_NUMA */

/*
* Common code for bitmap_*_region() routines.
--
2.20.1