mm: memory_hotplug: disable memmap_on_memory when hugetlb_free_vmemmap 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.

[akpm@linux-foundation.org: remove unneeded include, per Oscar]

Link: https://lkml.kernel.org/r/20210510030027.56044-9-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index b787a99..597572c 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/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>

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index ae7a07b..29d1d74 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/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) &&