memblock_alloc_base_nid() is a common API of memblock. And it calls memblock_find_in_range_node() with %start = 0, which means it has no limit for the lowest address by default. memblock_find_in_range_node(0, max_addr, size, align, nid); Since we introduced current_limit_low to memblock, if we have no limit for the lowest address or we are not sure, we should pass MEMBLOCK_ALLOC_ACCESSIBLE to %start so that it will be limited by the default low limit. dma_contiguous_reserve() and setup_log_buf() will eventually call memblock_alloc_base_nid() to allocate memory. So if the allocation order is from low to high, they will allocate memory from the lowest limit to higher memory. Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx> Reviewed-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx> --- mm/memblock.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index 961d4a5..be8c4d1 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -851,7 +851,8 @@ static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size, /* align @size to avoid excessive fragmentation on reserved array */ size = round_up(size, align); - found = memblock_find_in_range_node(0, max_addr, size, align, nid); + found = memblock_find_in_range_node(MEMBLOCK_ALLOC_ACCESSIBLE, + max_addr, size, align, nid); if (found && !memblock_reserve(found, size)) return found; -- 1.7.1 -- 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=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>