Re: [PATCH 03/16] mm: remove obsolete macro NR_PCP_ORDER_MASK

[Matthew Wilcox]

On Fri, Sep 09, 2022 at 05:24:38PM +0800, Miaohe Lin wrote:
> Since commit 8b10b465d0e1 ("mm/page_alloc: free pages in a single pass
> during bulk free"), it's not used anymore. Remove it.

Yes, but this patch needs to go further.  The comment is no longer true
(after the patch you mention), so need to also delete these lines:

-/*
- * Shift to encode migratetype and order in the same integer, with order
- * in the least significant bits.
- */
-#define NR_PCP_ORDER_WIDTH 8

and the line:
-                BUILD_BUG_ON(MAX_ORDER >= (1<<NR_PCP_ORDER_WIDTH));