Re: linux-next: Tree for Oct 15

Hi all,

On Tue, 16 Oct 2018 13:02:16 +1100 Stephen Rothwell [off-list ref] wrote:

Reverting fe3d2a45e8079fdd7d4da1ff07f4b40bc3cb499f (and the following 2
commits) produces a kernel that boots.

Instead of that, I applied this patch on top of linux-next and it boots
and produces a stack trace ...

From: Stephen Rothwell <redacted>
Date: Tue, 16 Oct 2018 13:07:01 +1100
Subject: [PATCH] mm/memblock.c: use dump_stack() instead of WARN_ON_ONCE for
 the alignment checks

Using WARN_ON_ONCE too early causes the PowerPC kernel to fail.

Signed-off-by: Stephen Rothwell <redacted>
---
 mm/memblock.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 5fefc70253ee..f2ef3915a356 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c

@@ -1298,8 +1298,10 @@ static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
 {
 	phys_addr_t found;
 
-	if (WARN_ON_ONCE(!align))
+	if (!align) {
+		dump_stack();
 		align = SMP_CACHE_BYTES;
+	}
 
 	found = memblock_find_in_range_node(size, align, start, end, nid,
 					    flags);

@@ -1423,8 +1425,10 @@ static void * __init memblock_alloc_internal(
 	if (WARN_ON_ONCE(slab_is_available()))
 		return kzalloc_node(size, GFP_NOWAIT, nid);
 
-	if (WARN_ON_ONCE(!align))
+	if (!align) {
+		dump_stack();
 		align = SMP_CACHE_BYTES;
+	}
 
 	if (max_addr > memblock.current_limit)
 		max_addr = memblock.current_limit;

-- 
2.18.0

So, patch "memblock: stop using implicit alignment to SMP_CACHE_BYTES"
should *not* remove the 0 -> SMP_CACHE_BYTES update from mm/memblock.c
and just add the dump_stack().
-- 
Cheers,
Stephen Rothwell