Re: [HMM v15 01/16] mm/free_hot_cold_page: catch ZONE_DEVICE pages
From: Dave Hansen
Date: Mon Jan 09 2017 - 11:22:40 EST
On 01/09/2017 01:19 AM, Balbir Singh wrote:
>> + /*
>> + * This should never happen ! Page from ZONE_DEVICE always must have an
>> + * active refcount. Complain about it and try to restore the refcount.
>> + */
>> + if (is_zone_device_page(page)) {
>> + VM_BUG_ON_PAGE(is_zone_device_page(page), page);
> This can be VM_BUG_ON_PAGE(1, page), hopefully the compiler does the right thing
> here. I suspect this should be a BUG_ON, independent of CONFIG_DEBUG_VM
BUG_ON() means "kill the machine dead". Do we really want a guaranteed
dead machine if someone screws up their refcounting?