Hi I find the show_mem function show page MIGRATE types result is not correct for MIGRATE_RESERVE pages : Normal: 1582*4kB (UEMC) 1317*8kB (UEMC) 1020*16kB (UEMC) 450*32kB (UEMC) 206*64kB (UEMC) 40*128kB (UM) 10*256kB (UM) 10*512kB (UM) 1*1024kB (M) 0*2048kB 0*4096kB = 74592kB Some pages should be marked (R) , while it is changed into MIGRATE_MOVEABLE or UNMOVEABLE in free_area list , It's not correct for debug . I make a patch for this: diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5dba293..6ef8ebe 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1198,7 +1198,8 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, list_add_tail(&page->lru, list); if (IS_ENABLED(CONFIG_CMA)) { mt = get_pageblock_migratetype(page); - if (!is_migrate_cma(mt) && !is_migrate_isolate(mt)) + if (!is_migrate_cma(mt) && !is_migrate_isolate(mt) + && mt != MIGRATE_RESERVE) mt = migratetype; } set_freepage_migratetype(page, mt); seems work ok , I am curious is it a BUG ? or designed like this for some reason ? Thanks <6>[ 250.751554] lowmem_reserve[]: 0 0 0 <6>[ 250.751606] Normal: 1582*4kB (UEMC) 1317*8kB (UEMC) 1020*16kB (UEMC) 450*32kB (UEMC) 206*64kB (UEMC) 40*128kB (UM) 10*256kB (UM) 10*512kB (UM) 1*1024kB (M) 0*2048kB 0*4096kB = 74592kB <6>[ 250.751848] HighMem: 167*4kB (UC) 3*8kB (U) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 692kB <6>[ 250.752020] 62596 total pagecache pages <6>[ 250.752046] 0 pages in swap cache <6>[ 250.752074] Swap cache stats: add 0, delete 0, find 0/0 Sony Mobile Communications Tel: My Number +18610323092 yalin.wang@xxxxxxxxxxxxxx sonymobile.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href