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| author | Mike Rapoport <rppt@linux.ibm.com> | 2021-05-17 21:15:15 +0300 |
|---|---|---|
| committer | Mike Rapoport <rppt@linux.ibm.com> | 2021-06-30 11:38:33 +0300 |
| commit | e2a86800d58639b3acde7eaeb9eb393dca066e08 (patch) | |
| tree | 964e0c209239ff75e7aa615af95bade6f1eef368 /mm/memblock.c | |
| parent | c4681547bcce777daf576925a966ffa824edd09d (diff) | |
| download | lwn-e2a86800d58639b3acde7eaeb9eb393dca066e08.tar.gz lwn-e2a86800d58639b3acde7eaeb9eb393dca066e08.zip | |
memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER
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 <rppt@linux.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'mm/memblock.c')
| -rw-r--r-- | mm/memblock.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/mm/memblock.c b/mm/memblock.c index afaefa8fc6ab..97fa87541b5f 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1943,11 +1943,11 @@ static void __init free_unused_memmap(void) start = min(start, 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 /* @@ -1958,11 +1958,11 @@ 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 |