> > > > spin_lock(&deferred_zone_grow_lock); > > > > - static_branch_disable(&deferred_pages); > > > > + deferred_zone_grow = false; > > > > spin_unlock(&deferred_zone_grow_lock); > > > > + static_branch_disable(&deferred_pages); > > > > > > > > /* There will be num_node_state(N_MEMORY) threads */ > > > > atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY)); > > > > > > Kinda ugly, but I can see the logic behind the decisions. > > > > > > Can we instead turn deferred_zone_grow_lock into a mutex? > > (top-posting repaired. Please don't top-post). > > > [CCed everyone] > > > > Hi Andrew, > > > > I afraid we cannot change this spinlock to mutex > > because deferred_grow_zone() might be called from an interrupt context if > > interrupt thread needs to allocate memory. > > > > OK. But if deferred_grow_zone() can be called from interrupt then > page_alloc_init_late() should be using spin_lock_irq(), shouldn't it? > I'm surprised that lockdep didn't detect that.
No, page_alloc_init_late() cannot be called from interrupt, it is called straight from: kernel_init_freeable(). But, I believe deferred_grow_zone(): can be called: get_page_from_freelist() _deferred_grow_zone() deferred_grow_zone() > > > > --- a/mm/page_alloc.c~mm-initialize-pages-on-demand-during-boot-fix-4-fix > +++ a/mm/page_alloc.c > @@ -1689,9 +1689,9 @@ void __init page_alloc_init_late(void) > * context. Since, spin_lock() disables preemption, we must use an > * extra boolean deferred_zone_grow. > */ > - spin_lock(&deferred_zone_grow_lock); > + spin_lock_irq(&deferred_zone_grow_lock); > deferred_zone_grow = false; > - spin_unlock(&deferred_zone_grow_lock); > + spin_unlock_irq(&deferred_zone_grow_lock); > static_branch_disable(&deferred_pages); > > /* There will be num_node_state(N_MEMORY) threads */ > _ > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majord...@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"d...@kvack.org";> em...@kvack.org </a>
