On Tue 10-09-19 18:58:05, Yunsheng Lin wrote: > On 2019/9/10 17:31, Greg KH wrote: > > On Tue, Sep 10, 2019 at 02:43:32PM +0800, Yunsheng Lin wrote: > >> On 2019/9/9 17:53, Greg KH wrote: > >>> On Mon, Sep 09, 2019 at 02:04:23PM +0800, Yunsheng Lin wrote: > >>>> Currently a device does not belong to any of the numa nodes > >>>> (dev->numa_node is NUMA_NO_NODE) when the node id is neither > >>>> specified by fw nor by virtual device layer and the device has > >>>> no parent device. > >>> > >>> Is this really a problem? > >> > >> Not really. > >> Someone need to guess the node id when it is not specified, right? > > > > No, why? Guessing guarantees you will get it wrong on some systems. > > > > Are you seeing real problems because the id is not being set? What > > problem is this fixing that you can actually observe? > > When passing the return value of dev_to_node() to cpumask_of_node() > without checking the node id if the node id is not valid, there is > global-out-of-bounds detected by KASAN as below:
OK, I seem to remember this being brought up already. And now when I think about it, we really want to make cpumask_of_node NUMA_NO_NODE aware. That means using the same trick the allocator does for this special case. -- Michal Hocko SUSE Labs