On 25.08.22 11:20, Aneesh Kumar K.V wrote:
> On memory hot unplug, the kernel removes the node memory type
> from the associated memory tier. Use list_del_init instead of
> list del such that the same memory type can be added back
> to a memory tier on hotplug.
>
> Without this, we get the below warning and return error on
> adding memory type to a new memory tier.
>
> [ 33.596095] ------------[ cut here ]------------
> [ 33.596099] WARNING: CPU: 3 PID: 667 at mm/memory-tiers.c:115 set_node_memory_tier+0xd6/0x2e0
> [ 33.596109] Modules linked in: kmem
>
> ...
>
> [ 33.596126] RIP: 0010:set_node_memory_tier+0xd6/0x2e0
>
> ....
> [ 33.596196] memtier_hotplug_callback+0x48/0x68
> [ 33.596204] blocking_notifier_call_chain+0x80/0xc0
> [ 33.596211] online_pages+0x25e/0x280
> [ 33.596218] memory_block_change_state+0x176/0x1f0
> [ 33.596225] memory_subsys_online+0x37/0x40
> [ 33.596230] online_store+0x9b/0x130
> [ 33.596236] kernfs_fop_write_iter+0x128/0x1b0
> [ 33.596242] vfs_write+0x24b/0x2c0
> [ 33.596249] ksys_write+0x74/0xe0
> [ 33.596254] do_syscall_64+0x43/0x90
> [ 33.596259] entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> Fixes: mm/demotion: Add hotplug callbacks to handle new numa node onlined
Do we have a proper 12-digit commit id as well?
Do we have to cc stable?
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
> ---
> mm/memory-tiers.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
> index a20795bb0e07..ba844fe9cc8c 100644
> --- a/mm/memory-tiers.c
> +++ b/mm/memory-tiers.c
> @@ -451,7 +451,7 @@ static bool clear_node_memory_tier(int node)
> memtype = node_memory_types[node];
> node_clear(node, memtype->nodes);
> if (nodes_empty(memtype->nodes)) {
> - list_del(&memtype->tier_sibiling);
> + list_del_init(&memtype->tier_sibiling);
> if (list_empty(&memtier->memory_types))
> destroy_memory_tier(memtier);
> }
--
Thanks,
David / dhildenb
