On Mon, Dec 13, 2021 at 04:57:06PM +0800, Mark-PK Tsai wrote: > Subject: [PATCH 5.4 1/5] memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER I'd replace memblock: with arm: in the subject. I believe it's clearer this way. The same applies for the second patch in the series and for 5.10 posting. > From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > commit e2a86800d58639b3acde7eaeb9eb393dca066e08 upstream. > > 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@xxxxxxxxxxxxx> > Tested-by: Tony Lindgren <tony@xxxxxxxxxxx> > Link: https://lore.kernel.org/lkml/20210630071211.21011-1-rppt@xxxxxxxxxx/ > [backport upstream modification in mm/memblock.c to arch/arm/mm/init.c] > Signed-off-by: Mark-PK Tsai <mark-pk.tsai@xxxxxxxxxxxx> > --- > 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 7ea4d3b43444..6905dd8bc03f 100644 > --- a/arch/arm/mm/init.c > +++ b/arch/arm/mm/init.c > @@ -381,11 +381,11 @@ 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 > @@ -395,12 +395,12 @@ 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(memblock_region_memory_end_pfn(reg), > - MAX_ORDER_NR_PAGES); > + pageblock_nr_pages); > } > > #ifdef CONFIG_SPARSEMEM > -- > 2.18.0 > -- Sincerely yours, Mike.
