mm: memory_hotplug: disable memmap_on_memory when hugetlb_free_vmemma…

…p enabled

The parameter of memory_hotplug.memmap_on_memory is not compatible with
hugetlb_free_vmemmap.  So disable it when hugetlb_free_vmemmap is enabled.

[[email protected]: remove unneeded include, per Oscar]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Muchun Song <[email protected]>
Acked-by: Mike Kravetz <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Bodeddula Balasubramaniam <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Chen Huang <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: HORIGUCHI NAOYA <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Joao Martins <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mina Almasry <[email protected]>
Cc: Oliver Neukum <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Pawan Gupta <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Xiongchun Duan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Documentation/admin-guide/kernel-parameters.txt

@@ -1584,6 +1584,10 @@
 			on:  enable the feature
 			off: disable the feature
 
+			This is not compatible with memory_hotplug.memmap_on_memory.
+			If both parameters are enabled, hugetlb_free_vmemmap takes
+			precedence over memory_hotplug.memmap_on_memory.
+
 	hung_task_panic=
 			[KNL] Should the hung task detector generate panics.
 			Format: 0 | 1
@@ -2850,6 +2854,10 @@
 			Note that even when enabled, there are a few cases where
 			the feature is not effective.
 
+			This is not compatible with hugetlb_free_vmemmap. If
+			both parameters are enabled, hugetlb_free_vmemmap takes
+			precedence over memory_hotplug.memmap_on_memory.
+
 	memtest=	[KNL,X86,ARM,PPC,RISCV] Enable memtest
 			Format: <integer>
 			default : 0 <disable>

mm/memory_hotplug.c

@@ -1056,6 +1056,7 @@ bool mhp_supports_memmap_on_memory(unsigned long size)
 	 *       populate a single PMD.
 	 */
 	return memmap_on_memory &&
+	       !is_hugetlb_free_vmemmap_enabled() &&
 	       IS_ENABLED(CONFIG_MHP_MEMMAP_ON_MEMORY) &&
 	       size == memory_block_size_bytes() &&
 	       IS_ALIGNED(vmemmap_size, PMD_SIZE) &&