Subject: Re: linux-next: build failure after merge of the mm tree

From: Matthew Wilcox <[email-masked]>
Date: Tue, 22 Aug 2023 02:11:44 +0100

On Tue, Aug 22, 2023 at 09:55:37AM +1000, Stephen Rothwell wrote:
> In file included from include/trace/trace_events.h:27,
>                  from include/trace/define_trace.h:102,
>                  from fs/xfs/xfs_trace.h:4428,
>                  from fs/xfs/xfs_trace.c:45:
> include/linux/pgtable.h:8:25: error: initializer element is not constant
>     8 | #define PMD_ORDER       (PMD_SHIFT - PAGE_SHIFT)

Ummm.  PowerPC doesn't have a compile-time constant PMD size?

arch/powerpc/include/asm/book3s/64/pgtable.h:#define PMD_SHIFT  (PAGE_SHIFT + PTE_INDEX_SIZE)
arch/powerpc/include/asm/book3s/64/pgtable.h:#define PTE_INDEX_SIZE  __pte_index_size

That's really annoying.  I'll try to work around it.