Commit 3c5f2eb9 authored Jul 14, 2020 by Heiko Carstens

s390/mm: avoid trimming to MAX_ORDER



Trimming to MAX_ORDER was originally done in order to avoid to set
HOLES_IN_ZONE, which in turn would enable a quite expensive
pfn_valid() check. pfn_valid() however only checks if a struct page
exists for a given pfn.

With sparsemen vmemmap there are always struct pages, since memmaps
are allocated for whole sections. Therefore remove the HOLES_IN_ZONE
comment and the trimming.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

parent a709423f

arch/s390/kernel/setup.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -1126,14 +1126,6 @@ void __init setup_arch(char **cmdline_p)
		free_mem_detect_info();
		remove_oldmem();

		/*
		* Make sure all chunks are MAX_ORDER aligned so we don't need the
		* extra checks that HOLES_IN_ZONE would require.
		*
		* Is this still required?
		*/
		memblock_trim_memory(1UL << (MAX_ORDER - 1 + PAGE_SHIFT));

		if (is_prot_virt_host())
		setup_uv();
		setup_memory_end();

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