The parameter of memory_hotplug.memmap_on_memory is not compatible with
hugetlb_free_vmemmap. So disable it when hugetlb_free_vmemmap is
enabled.
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 4 ++++
drivers/acpi/acpi_memhotplug.c | 1 +
mm/memory_hotplug.c | 18 +++++++++++++-----
3 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9e655f5206ac..1f648b3e6120 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2893,6 +2893,10 @@
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/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 8cc195c4c861..0d7f595ee441 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -15,6 +15,7 @@
#include <linux/acpi.h>
#include <linux/memory.h>
#include <linux/memory_hotplug.h>
+#include <linux/hugetlb.h>
#include "internal.h"
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 68923c19bdea..c45ed6c0cd9f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -981,6 +981,7 @@ static int online_memory_block(struct memory_block *mem, void *arg)
bool mhp_supports_memmap_on_memory(unsigned long size)
{
+ bool supported;
unsigned long nr_vmemmap_pages = size / PAGE_SIZE;
unsigned long vmemmap_size = nr_vmemmap_pages * sizeof(struct page);
unsigned long remaining_size = size - vmemmap_size;
@@ -1011,11 +1012,18 @@ 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 &&
- IS_ENABLED(CONFIG_MHP_MEMMAP_ON_MEMORY) &&
- size == memory_block_size_bytes() &&
- IS_ALIGNED(vmemmap_size, PMD_SIZE) &&
- IS_ALIGNED(remaining_size, pageblock_nr_pages << PAGE_SHIFT);
+ supported = memmap_on_memory &&
+ IS_ENABLED(CONFIG_MHP_MEMMAP_ON_MEMORY) &&
+ size == memory_block_size_bytes() &&
+ IS_ALIGNED(vmemmap_size, PMD_SIZE) &&
+ IS_ALIGNED(remaining_size, pageblock_nr_pages << PAGE_SHIFT);
+
+ if (supported && is_hugetlb_free_vmemmap_enabled()) {
+ pr_info("Cannot enable memory_hotplug.memmap_on_memory, it is not compatible with hugetlb_free_vmemmap\n");
+ supported = false;
+ }
+
+ return supported;
}
/*
--
2.11.0
