Messages in this thread | | | Date | Mon, 25 Apr 2016 15:18:16 -0700 | From | Yu Zhao <> | Subject | Re: [PATCH] mm/zpool: use workqueue for zpool_destroy |
| |
On Mon, Apr 25, 2016 at 05:20:10PM -0400, Dan Streetman wrote: > Add a work_struct to struct zpool, and change zpool_destroy_pool to > defer calling the pool implementation destroy. > > The zsmalloc pool destroy function, which is one of the zpool > implementations, may sleep during destruction of the pool. However > zswap, which uses zpool, may call zpool_destroy_pool from atomic > context. So we need to defer the call to the zpool implementation > to destroy the pool. > > This is essentially the same as Yu Zhao's proposed patch to zsmalloc, > but moved to zpool.
Thanks, Dan. Sergey also mentioned another call path that triggers the same problem (BUG: scheduling while atomic): rcu_process_callbacks() __zswap_pool_release() zswap_pool_destroy() zswap_cpu_comp_destroy() cpu_notifier_register_begin() mutex_lock(&cpu_add_remove_lock); So I was thinking zswap_pool_destroy() might be done in workqueue in zswap.c. This way we fix both call paths.
Or you have another patch to fix the second call path?
| |