From e3d301cae0092062cbcd6b4e7ceebbab9d87e263 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 13 Jul 2018 16:59:16 -0700 Subject: mm/memblock.c: do not complain about top-down allocations for !MEMORY_HOTREMOVE Mike Rapoport is converting architectures from bootmem to nobootmem allocator. While doing so for m68k Geert has noticed that he gets a scary looking warning: WARNING: CPU: 0 PID: 0 at mm/memblock.c:230 memblock_find_in_range_node+0x11c/0x1be memblock: bottom-up allocation failed, memory hotunplug may be affected Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.18.0-rc3-atari-01343-gf2fb5f2e09a97a3c-dirty #7 Call Trace: __warn+0xa8/0xc2 kernel_pg_dir+0x0/0x1000 netdev_lower_get_next+0x2/0x22 warn_slowpath_fmt+0x2e/0x36 memblock_find_in_range_node+0x11c/0x1be memblock_find_in_range_node+0x11c/0x1be memblock_find_in_range_node+0x0/0x1be vprintk_func+0x66/0x6e memblock_virt_alloc_internal+0xd0/0x156 netdev_lower_get_next+0x2/0x22 netdev_lower_get_next+0x2/0x22 kernel_pg_dir+0x0/0x1000 memblock_virt_alloc_try_nid_nopanic+0x58/0x7a netdev_lower_get_next+0x2/0x22 kernel_pg_dir+0x0/0x1000 kernel_pg_dir+0x0/0x1000 EXPTBL+0x234/0x400 EXPTBL+0x234/0x400 alloc_node_mem_map+0x4a/0x66 netdev_lower_get_next+0x2/0x22 free_area_init_node+0xe2/0x29e EXPTBL+0x234/0x400 paging_init+0x430/0x462 kernel_pg_dir+0x0/0x1000 printk+0x0/0x1a EXPTBL+0x234/0x400 setup_arch+0x1b8/0x22c start_kernel+0x4a/0x40a _sinittext+0x344/0x9e8 The warning is basically saying that a top-down allocation can break memory hotremove because memblock allocation is not movable. But m68k doesn't even support MEMORY_HOTREMOVE so there is no point to warn about it. Make the warning conditional only to configurations that care. Link: http://lkml.kernel.org/r/20180706061750.GH32658@dhcp22.suse.cz Signed-off-by: Michal Hocko Reported-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Reviewed-by: Andrew Morton Cc: Vlastimil Babka Cc: Mike Rapoport Cc: Greg Ungerer Cc: Sam Creasey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memblock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/memblock.c b/mm/memblock.c index 03d48d8835ba..11e46f83e1ad 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -227,7 +227,8 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size, * so we use WARN_ONCE() here to see the stack trace if * fail happens. */ - WARN_ONCE(1, "memblock: bottom-up allocation failed, memory hotunplug may be affected\n"); + WARN_ONCE(IS_ENABLED(CONFIG_MEMORY_HOTREMOVE), + "memblock: bottom-up allocation failed, memory hotremove may be affected\n"); } return __memblock_find_range_top_down(start, end, size, align, nid, -- cgit v1.2.3