8bc0868998
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
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 # v4.20+
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.