[PATCH 4/6] mm/memblock: remove consecutive regions at once

[Wei Yang <richard.weiyang@gmail.com>]

In memblock_remove_range, we would remove consecutive regions after
isolation.

Instead of removing each region from end to start one by one, we could
remove those consecutive regions at once.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
 mm/memblock.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 2d7a2431803f..3fecee4bd41a 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -343,12 +343,15 @@ static phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
 	return ret;
 }
 
-static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
+static void __init_memblock memblock_remove_regions(struct memblock_type *type,
+						    unsigned long r,
+						    unsigned int num)
 {
-	type->total_size -= type->regions[r].size;
-	memmove(&type->regions[r], &type->regions[r + 1],
-		(type->cnt - (r + 1)) * sizeof(type->regions[r]));
-	type->cnt--;
+	for (int i = 0; i < num; i++)
+		type->total_size -= type->regions[r + i].size;
+	memmove(&type->regions[r], &type->regions[r + num],
+		(type->cnt - (r + num)) * sizeof(type->regions[r]));
+	type->cnt -= num;
 
 	/* Special case for empty arrays */
 	if (type->cnt == 0) {
@@ -360,6 +363,11 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u
 	}
 }
 
+static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
+{
+	memblock_remove_regions(type, r, 1);
+}
+
 #ifndef CONFIG_ARCH_KEEP_MEMBLOCK
 /**
  * memblock_discard - discard memory and reserved arrays if they were allocated
@@ -816,14 +824,14 @@ static int __init_memblock memblock_remove_range(struct memblock_type *type,
 					  phys_addr_t base, phys_addr_t size)
 {
 	int start_rgn, end_rgn;
-	int i, ret;
+	int ret;
 
 	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
 	if (ret)
 		return ret;
 
-	for (i = end_rgn - 1; i >= start_rgn; i--)
-		memblock_remove_region(type, i);
+	if (end_rgn - start_rgn)
+		memblock_remove_regions(type, start_rgn, end_rgn - start_rgn);
 	return 0;
 }
 
-- 
2.34.1