Re: [PATCH 3/5] Switch caches notification dynamically

[Pavel Emelyanov <xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>]

Christoph Lameter wrote:
> On Tue, 25 Sep 2007, Pavel Emelyanov wrote:
> 
>> +		for_each_node_state(n, N_NORMAL_MEMORY) {
>> +			struct kmem_cache_node *node;
>> +			struct page *pg;
>> +			
>> +			node = get_node(s, n);
>> +			spin_lock_irq(&node->list_lock);
>> +			list_for_each_entry(pg, &node->partial, lru)
>> +				SetSlabDebug(pg);
>> +			spin_unlock_irq(&node->list_lock);
> 
> 
> Is it necessary to mark all the existing slabs with SLAB_DEBUG? Would it 

Yup. Otherwise we can never receive a single event e.g. if we make 
alloc/free in a loop, or similar, so that new slabs simply are not 
created.

> not be sufficient to just mark the new ones coming up? The above operation 
> could be a bit expensive.

Oh, that's OK from my POV - switching slabs mode was never supposed to
be a fast path.

Thanks,
Pavel