From 6b9d7c8e8ecf35dc9ba6763a45d81e54ee3ffcde Mon Sep 17 00:00:00 2001 From: "Dennis Zhou (Facebook)" Date: Mon, 24 Jul 2017 19:02:03 -0400 Subject: percpu: end chunk area maps page aligned for the populated bitmap The area map allocator manages the first chunk area by hiding all but the region it is responsible for serving in the area map. To align this with the populated page bitmap, end_offset is introduced to keep track of the delta to end page aligned. The area map is appended with the page aligned end when necessary to be in line with how the bitmap allocator requires the ending to be aligned with the LCM of PAGE_SIZE and the size of each bitmap block. percpu_stats is updated to ignore this region when present. Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik Signed-off-by: Tejun Heo --- mm/percpu.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'mm/percpu.c') diff --git a/mm/percpu.c b/mm/percpu.c index 2e785a77ce14..1d2c980fde3f 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -715,12 +715,16 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(void *base_addr, int init_map_size) { struct pcpu_chunk *chunk; + int region_size; + + region_size = PFN_ALIGN(start_offset + map_size); chunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0); INIT_LIST_HEAD(&chunk->list); INIT_LIST_HEAD(&chunk->map_extend_list); chunk->base_addr = base_addr; chunk->start_offset = start_offset; + chunk->end_offset = region_size - chunk->start_offset - map_size; chunk->map = map; chunk->map_alloc = init_map_size; @@ -735,6 +739,11 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(void *base_addr, chunk->map[2] = (chunk->start_offset + chunk->free_size) | 1; chunk->map_used = 2; + if (chunk->end_offset) { + /* hide the end of the bitmap */ + chunk->map[++chunk->map_used] = region_size | 1; + } + return chunk; } -- cgit