Re: powerpc/mm: Only define MAX_PHYSMEM_BITS in SPARSEMEM configurations
From: Michael Ellerman <hidden>
Date: 2019-03-22 12:25:35
On Sun, 2019-03-17 at 01:17:56 UTC, Ben Hutchings wrote:
MAX_PHYSMEM_BITS only needs to be defined if CONFIG_SPARSEMEM is
enabled, and that was the case before commit 4ffe713b7587
("powerpc/mm: Increase the max addressable memory to 2PB").
On 32-bit systems, where CONFIG_SPARSEMEM is not enabled, we now
define it as 46. That is larger than the real number of physical
address bits, and breaks calculations in zsmalloc:
mm/zsmalloc.c:130:49: warning: right shift count is negative [-Wshift-count-negative]
MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
^~
...
mm/zsmalloc.c:253:21: error: variably modified 'size_class' at file scope
struct size_class *size_class[ZS_SIZE_CLASSES];
^~~~~~~~~~
Fixes: 4ffe713b7587 ("powerpc/mm: Increase the max addressable memory to 2PB")
Cc: stable@vger.kernel.org
Signed-off-by: Ben Hutchings <redacted>Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/8bc086899816214fbc6047c9c7e15fca cheers