Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> --- This is dependent on patches posted at https://lore.kernel.org/linux-mm/20230718024409.95742-1-aneesh.kumar@xxxxxxxxxxxxx/ 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
