[PATCH 5.10 1/5] memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER
From: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Date: 2021-12-13 09:45:54
Also in:
linux-mm, lkml, stable
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
From: Mike Rapoport <redacted> [ Upstream commit e2a86800d58639b3acde7eaeb9eb393dca066e08 ] The code that frees unused memory map uses rounds start and end of the holes that are freed to MAX_ORDER_NR_PAGES to preserve continuity of the memory map for MAX_ORDER regions. Lots of core memory management functionality relies on homogeneity of the memory map within each pageblock which size may differ from MAX_ORDER in certain configurations. Although currently, for the architectures that use free_unused_memmap(), pageblock_order and MAX_ORDER are equivalent, it is cleaner to have common notation thought mm code. Replace MAX_ORDER_NR_PAGES with pageblock_nr_pages and update the comments to make it more clear why the alignment to pageblock boundaries is required. Signed-off-by: Mike Rapoport <redacted> Tested-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/lkml/20210630071211.21011-1-rppt@kernel.org/ (local) [backport upstream modification in mm/memblock.c to arch/arm/mm/init.c] Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> --- arch/arm/mm/init.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 75f3ab531bdf..8440b6027598 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c@@ -315,11 +315,11 @@ static void __init free_unused_memmap(void) ALIGN(prev_end, PAGES_PER_SECTION)); #else /* - * Align down here since the VM subsystem insists that the - * memmap entries are valid from the bank start aligned to - * MAX_ORDER_NR_PAGES. + * Align down here since many operations in VM subsystem + * presume that there are no holes in the memory map inside + * a pageblock */ - start = round_down(start, MAX_ORDER_NR_PAGES); + start = round_down(start, pageblock_nr_pages); #endif /* * If we had a previous bank, and there is a space
@@ -329,11 +329,11 @@ static void __init free_unused_memmap(void) free_memmap(prev_end, start); /* - * Align up here since the VM subsystem insists that the - * memmap entries are valid from the bank end aligned to - * MAX_ORDER_NR_PAGES. + * Align up here since many operations in VM subsystem + * presume that there are no holes in the memory map inside + * a pageblock */ - prev_end = ALIGN(end, MAX_ORDER_NR_PAGES); + prev_end = ALIGN(end, pageblock_nr_pages); } #ifdef CONFIG_SPARSEMEM
--
2.18.0
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