[PATCH 1/2] mm/mm_init: don't overlap NORMAL and MOVABLE zones with kernelcore=mirror

[Mike Rapoport <rppt@kernel.org>]

From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>

When kernelcore or movablecore kernel parameters define size of the
NORMAL and MOVABLE zones as percents of the total memory or by absolute
value, ZONE_NORMAL is clamped at the beginning of ZONE_MOVABLE.

However, when kernelcore=mirror the ZONE_NORMAL span is not changed but
rather pages from ZONE_MOVABLE counted as absent in ZONE_NORMAL.

Make the behaviour of kernelcore= parameter uniform and treat mirror
just as another way to size the zones.

Co-developed-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 mm/mm_init.c | 36 +++---------------------------------
 1 file changed, 3 insertions(+), 33 deletions(-)

diff --git a/mm/mm_init.c b/mm/mm_init.c
index f9f8e1af921c..dce9dc9f2302 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1159,9 +1159,8 @@ static void __init adjust_zone_range_for_zone_movable(int nid,
 				arch_zone_highest_possible_pfn[movable_zone]);
 
 		/* Adjust for ZONE_MOVABLE starting within this range */
-		} else if (!mirrored_kernelcore &&
-			*zone_start_pfn < zone_movable_pfn[nid] &&
-			*zone_end_pfn > zone_movable_pfn[nid]) {
+		} else if (*zone_start_pfn < zone_movable_pfn[nid] &&
+			   *zone_end_pfn > zone_movable_pfn[nid]) {
 			*zone_end_pfn = zone_movable_pfn[nid];
 
 		/* Check if this whole range is within ZONE_MOVABLE */
@@ -1209,40 +1208,11 @@ static unsigned long __init zone_absent_pages_in_node(int nid,
 					unsigned long zone_start_pfn,
 					unsigned long zone_end_pfn)
 {
-	unsigned long nr_absent;
-
 	/* zone is empty, we don't have any absent pages */
 	if (zone_start_pfn == zone_end_pfn)
 		return 0;
 
-	nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
-
-	/*
-	 * ZONE_MOVABLE handling.
-	 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
-	 * and vice versa.
-	 */
-	if (mirrored_kernelcore && zone_movable_pfn[nid]) {
-		unsigned long start_pfn, end_pfn;
-		struct memblock_region *r;
-
-		for_each_mem_region(r) {
-			start_pfn = clamp(memblock_region_memory_base_pfn(r),
-					  zone_start_pfn, zone_end_pfn);
-			end_pfn = clamp(memblock_region_memory_end_pfn(r),
-					zone_start_pfn, zone_end_pfn);
-
-			if (zone_type == ZONE_MOVABLE &&
-			    memblock_is_mirror(r))
-				nr_absent += end_pfn - start_pfn;
-
-			if (zone_type == ZONE_NORMAL &&
-			    !memblock_is_mirror(r))
-				nr_absent += end_pfn - start_pfn;
-		}
-	}
-
-	return nr_absent;
+	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
 }
 
 /*
-- 
2.53.0