On Fri, Dec 12, 2014 at 06:19:53PM +0800, Lai Jiangshan wrote: > Yasuaki Ishimatsu hit a bug when the numa mapping between CPU and node > is changed. And the previous path fixup wq_numa_possible_cpumask. > (See more information form the changelog of that patch) > > After wq_numa_possible_cpumask was updated, the new pool->node will be > correct, but the existing pools (and workers) are still running, some of > them are running with the wrong pool->node, or even worse, with pool->node > which is quitted node, they create_worker() on wrong pool->node. > These create_worker() may create workers on wrong node or failed without > any progress (when with pool->node which is quitted node). > > So we need to update the pool->node when the numa mapping is changed. > > We simply re-calc the pool->node when the numa mapping changed. It reuses > the code from get_unbound_pool() for unbound pool.
I don't get this patch. If a node is gone, all its cpus would be gone and the pool should be discarded. If a new node comes online with different mappings, new sets of pools should serve them instead of recycling the old ones. Wouldn't it make a lot more sense to make sure we don't reuse the pools w/ old mappings for new pwqs? Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
