Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
---
This is dependent on patches posted at
https://lore.kernel.org/linux-mm/20230718024409.95742-1-aneesh.ku...@linux.ibm.com/
mm/memory_hotplug.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 6a8adbe030f9..21a5113fe9be 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -86,7 +86,12 @@ static int set_memmap_mode(const char *val, const struct
kernel_param *kp)
mode = MEMMAP_ON_MEMORY_DISABLE;
matched:
+ /*
+ * Avoid changing memmap mode during hotplug.
+ */
+ get_online_mems();
*((int *)kp->arg) = mode;
+ put_online_mems();
if (mode == MEMMAP_ON_MEMORY_FORCE) {
pr_info("Memory hotplug will reserve %ld pages in each memory
block\n",
memory_block_align_base(memory_block_size_bytes()));
@@ -108,7 +113,7 @@ static const struct kernel_param_ops memmap_mode_ops = {
.set = set_memmap_mode,
.get = get_memmap_mode,
};
-module_param_cb(memmap_on_memory, &memmap_mode_ops, &memmap_mode, 0444);
+module_param_cb(memmap_on_memory, &memmap_mode_ops, &memmap_mode, 0644);
MODULE_PARM_DESC(memmap_on_memory, "Enable memmap on memory for memory
hotplug\n"
"With value \"force\" it could result in memory wastage due to memmap
size limitations \n"
"For example, if the memmap for a memory block requires 1 MiB, but the
pageblock \n"
@@ -2162,18 +2167,16 @@ 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 (mhp_memmap_on_memory()) {
- ret = walk_memory_blocks(start, size, &mhp_altmap,
- get_vmemmap_altmap_cb);
- if (ret) {
- if (size != memory_block_size_bytes()) {
- pr_warn("Refuse to remove %#llx - %#llx,"
- "wrong granularity\n",
- start, start + size);
- return -EINVAL;
- }
- altmap = &mhp_altmap;
+ ret = walk_memory_blocks(start, size, &mhp_altmap,
+ get_vmemmap_altmap_cb);
+ if (ret) {
+ if (size != memory_block_size_bytes()) {
+ pr_warn("Refuse to remove %#llx - %#llx,"
+ "wrong granularity\n",
+ start, start + size);
+ return -EINVAL;
}
+ altmap = &mhp_altmap;
}
/* remove memmap entry */
--
2.41.0
