On Mon, 2012-10-29 at 12:38 -0400, Vivek Goyal wrote: > Ok, so the question is what's wrong with calling synchronize_rcu() inside > a mutex with CONFIG_PREEMPT=y. I don't know. Ccing paul mckenney and > peterz. int blkcg_activate_policy(struct request_queue *q, { ... preloaded = !radix_tree_preload(GFP_KERNEL); blk_queue_bypass_start(q); where: int radix_tree_preload(gfp_t gfp_mask) { struct radix_tree_preload *rtp; struct radix_tree_node *node; int ret = -ENOMEM; preempt_disable(); Seems obvious why it explodes.. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel