Messages in this thread | | | Date | Mon, 10 Jul 2017 10:32:13 -0500 (CDT) | From | Christoph Lameter <> | Subject | Re: [PATCH] slub: make sure struct kmem_cache_node is initialized before publication |
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On Mon, 10 Jul 2017, Alexander Potapenko wrote:
> >> Could the slab maintainers please take a look at these and also have a > >> think about Alexander's READ_ONCE/WRITE_ONCE question? > > > > Was I cced on these? > I've asked Andrew about READ_ONCE privately.
Please post to a mailing list and cc the maintainers?
> Since unfreeze_partials() sees uninitialized value of n->list_lock, I > was suspecting there's a data race between unfreeze_partials() and > init_kmem_cache_nodes().
I have not seen the details but I would suspect that this is related to early boot issues? The list lock is initialized upon slab creation and at that time no one can get to the kmem_cache structure.
There are a couple of boot time slabs that will temporarily be available. and released upon boot completion.
> If so, reads and writes to s->node[node] must be acquire/release > atomics (not actually READ_ONCE/WRITE_ONCE, but > smp_load_acquire/smp_store_release).
Can we figure the reason for these out before proposing fixes?
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