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    SubjectRe: [PATCH] slab: Fix kmem_cache_destroy() on NUMA
    Roland Dreier wrote:
    > With CONFIG_NUMA set, kmem_cache_destroy() may fail and say "Can't
    > free all objects." The problem is caused by sequences such as the
    > following (suppose we are on a NUMA machine with two nodes, 0 and 1):
    > * Allocate an object from cache on node 0.
    > * Free the object on node 1. The object is put into node 1's alien
    > array_cache for node 0.
    > * Call kmem_cache_destroy(), which ultimately ends up in __cache_shrink().
    > * __cache_shrink() does drain_cpu_caches(), which loops through all nodes.
    > For each node it drains the shared array_cache and then handles the
    > alien array_cache for the other node.
    > However this means that node 0's shared array_cache will be drained,
    > and then node 1 will move the contents of its alien[0] array_cache
    > into that same shared array_cache. node 0's shared array_cache is
    > never looked at again, so the objects left there will appear to be in
    > use when __cache_shrink() calls __node_shrink() for node 0. So
    > __node_shrink() will return 1 and kmem_cache_destroy() will fail.
    > This patch fixes this by having drain_cpu_caches() do
    > drain_alien_cache() on every node before it does drain_array() on the
    > nodes' shared array_caches.
    > The problem was originally reported by Or Gerlitz <>.
    > Cc: Christoph Lameter <>
    > Cc: Pekka Enberg <>

    OK, Indeed i have CONFIG_NUMA and yes, the patch fixes my problem,
    thanks a lot for working on that!


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