sparsemem: make SPARSEMEM_VMEMMAP selectable (a5ee6daa) · Commits · 戴 / test

SPARSEMEM_VMEMMAP needs to be a selectable config option to support building the kernel both with and without sparsemem vmemmap support. This selection is desirable for platforms which could be configured one way for platform specific builds and the other for multi-platform builds. Signed-off-by:

Miguel Botón <mboton@gmail.com> Signed-off-by:

Geoff Levand <geoffrey.levand@am.sony.com> Acked-by:

Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/Kconfig

+7 −8

Original line number	Diff line number	Diff line
		@@ -112,18 +112,17 @@ config SPARSEMEM_EXTREME
		def_bool y
		depends on SPARSEMEM && !SPARSEMEM_STATIC

		#
		# SPARSEMEM_VMEMMAP uses a virtually mapped mem_map to optimise pfn_to_page
		# and page_to_pfn. The most efficient option where kernel virtual space is
		# not under pressure.
		#
		config SPARSEMEM_VMEMMAP_ENABLE
		def_bool n

		config SPARSEMEM_VMEMMAP
		bool
		depends on SPARSEMEM
		default y if (SPARSEMEM_VMEMMAP_ENABLE)
		bool "Sparse Memory virtual memmap"
		depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE
		default y
		help
		SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise
		pfn_to_page and page_to_pfn operations. This is the most
		efficient option when sufficient kernel resources are available.

		# eventually, we can have this option just 'select SPARSEMEM'
		config MEMORY_HOTPLUG

Admin message