> On 1 Oct 2017, at 15.25, Rakesh Pandit <rakesh@xxxxxxxxxx> wrote: > > While separating read and erase mempools in 22da65a1b pblk_g_rq_cache > was used two times to set aside memory both for erase and read > requests. Because same kmem cache is used repeatedly a single call to > kmem_cache_destroy wouldn't deallocate everything. Repeatedly doing > loading and unloading of pblk modules would eventually result in some > leak. > > The fix is to really use separate kmem cache and track it > appropriately. > > Fixes: 22da65a1b ("lightnvm: pblk: decouple read/erase mempools") > Signed-off-by: Rakesh Pandit <rakesh@xxxxxxxxxx> > I'm not sure I follow this logic. I assume that you're thinking of the refcount on kmem_cache. During cache creation, all is good; if a different cache creation fails, destruction is guaranteed, since the refcount is 0. On tear down (pblk_core_free), we destroy the mempools associated to the caches. In this case, the refcount goes to 0 too, as we destroy the 2 mempools. So I don't see where the leak can happen. Am I missing something? In any case, Jens reported some bugs on the mempools, where we did not guarantee forward progress. Here you can find the original discussion and the mempool audit [1]. Would be good if you reviewed these. [1] https://www.spinics.net/lists/kernel/msg2602274.html Thanks, Javier
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