Hi Oscar,
On 3/10/2022 1:48 PM, Oscar Salvador wrote:
On Thu, Mar 10, 2022 at 08:39:53AM +0800, Huang, Ying wrote:
We need to call set_migration_target_nodes() during system boot
somewhere, either here or in init_mm_internals().
Hi Huang Ying,
vmstat_cpu_online() already gets called during boot:
static struct cpuhp_step cpuhp_hp_states[] = {
...
#ifdef CONFIG_SMP
[CPUHP_CREATE_THREADS]= {
.name = "threads:prepare",
.startup.single = smpboot_create_threads,
.teardown.single = NULL,
.cant_stop = true,
},
...
smpboot_create_threads
__smpboot_create_thread
smpboot_thread_fn
ht->thread_fn()
cpuhp_thread_fun
cpuhp_invoke_callback
vmstat_cpu_online
That for every CPU that is brought up during boot.
So unless I am missing something, I would say we are already covered
there, right?
I've tested your patch, unfortunately it can not work. It already set
the node with N_CPU state in init_cpu_node_state() earlier, so in
vmstat_cpu_online() ,the sentence 'if(!node_state(cpu_to_node(cpu),
N_CPU))' is always false, which means it will not call
set_migration_target_nodes().
Like Huang Ying said, we should call set_migration_target_nodes() in
migrate_on_reclaim_init() or init_mm_internals().
