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authorMuchun Song <songmuchun@bytedance.com>2022-05-14 02:48:56 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-05-14 02:48:56 +0300
commit6e02c46b4d970f24eb51197d451b00f08a8a4186 (patch)
treea282366506ab21104487efa31b74a979f4898908 /mm/memory_hotplug.c
parent0effdf461c5789be02d40c1868c70cc02ea24627 (diff)
downloadlinux-6e02c46b4d970f24eb51197d451b00f08a8a4186.tar.xz
mm: memory_hotplug: override memmap_on_memory when hugetlb_free_vmemmap=on
Optimizing HugeTLB vmemmap pages is not compatible with allocating memmap on hot added memory. If "hugetlb_free_vmemmap=on" and memory_hotplug.memmap_on_memory" are both passed on the kernel command line, optimizing hugetlb pages takes precedence. However, the global variable memmap_on_memory will still be set to 1, even though we will not try to allocate memmap on hot added memory. Also introduce mhp_memmap_on_memory() helper to move the definition of "memmap_on_memory" to the scope of CONFIG_MHP_MEMMAP_ON_MEMORY. In the next patch, mhp_memmap_on_memory() will also be exported to be used in hugetlb_vmemmap.c. Link: https://lkml.kernel.org/r/20220512041142.39501-3-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory_hotplug.c')
-rw-r--r--mm/memory_hotplug.c32
1 files changed, 26 insertions, 6 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 945191708ef6..6951bf0bc2e6 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -42,14 +42,36 @@
#include "internal.h"
#include "shuffle.h"
+#ifdef CONFIG_MHP_MEMMAP_ON_MEMORY
+static int memmap_on_memory_set(const char *val, const struct kernel_param *kp)
+{
+ if (hugetlb_optimize_vmemmap_enabled())
+ return 0;
+ return param_set_bool(val, kp);
+}
+
+static const struct kernel_param_ops memmap_on_memory_ops = {
+ .flags = KERNEL_PARAM_OPS_FL_NOARG,
+ .set = memmap_on_memory_set,
+ .get = param_get_bool,
+};
/*
* memory_hotplug.memmap_on_memory parameter
*/
static bool memmap_on_memory __ro_after_init;
-#ifdef CONFIG_MHP_MEMMAP_ON_MEMORY
-module_param(memmap_on_memory, bool, 0444);
+module_param_cb(memmap_on_memory, &memmap_on_memory_ops, &memmap_on_memory, 0444);
MODULE_PARM_DESC(memmap_on_memory, "Enable memmap on memory for memory hotplug");
+
+static inline bool mhp_memmap_on_memory(void)
+{
+ return memmap_on_memory;
+}
+#else
+static inline bool mhp_memmap_on_memory(void)
+{
+ return false;
+}
#endif
enum {
@@ -1289,9 +1311,7 @@ bool mhp_supports_memmap_on_memory(unsigned long size)
* altmap as an alternative source of memory, and we do not exactly
* populate a single PMD.
*/
- return memmap_on_memory &&
- !hugetlb_optimize_vmemmap_enabled() &&
- IS_ENABLED(CONFIG_MHP_MEMMAP_ON_MEMORY) &&
+ return mhp_memmap_on_memory() &&
size == memory_block_size_bytes() &&
IS_ALIGNED(vmemmap_size, PMD_SIZE) &&
IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT));
@@ -2076,7 +2096,7 @@ static int __ref try_remove_memory(u64 start, u64 size)
* We only support removing memory added with MHP_MEMMAP_ON_MEMORY in
* the same granularity it was added - a single memory block.
*/
- if (memmap_on_memory) {
+ if (mhp_memmap_on_memory()) {
nr_vmemmap_pages = walk_memory_blocks(start, size, NULL,
get_nr_vmemmap_pages_cb);
if (nr_vmemmap_pages) {