Hello gentlemen, Commit 589a606f9539663f162e4a110d117527833b58a4 ("percpu: add preemption checks to __this_cpu ops") added preempt check to used in __count_vm_events() __this_cpu ops, causing the following kswapd warning: BUG: using __this_cpu_add() in preemptible [00000000] code: kswapd0/56 caller is __this_cpu_preempt_check+0x2b/0x2d Call Trace: [<ffffffff813b8d4d>] dump_stack+0x4e/0x7a [<ffffffff8121366f>] check_preemption_disabled+0xce/0xdd [<ffffffff812136bb>] __this_cpu_preempt_check+0x2b/0x2d [<ffffffff810f622e>] inode_lru_isolate+0xed/0x197 [<ffffffff810be43c>] list_lru_walk_node+0x7b/0x14c [<ffffffff810f6141>] ? iput+0x131/0x131 [<ffffffff810f681f>] prune_icache_sb+0x35/0x4c [<ffffffff810e3951>] super_cache_scan+0xe3/0x143 [<ffffffff810b1301>] shrink_slab_node+0x103/0x16f [<ffffffff810b19fd>] shrink_slab+0x75/0xe4 [<ffffffff810b3f3d>] balance_pgdat+0x2fa/0x47f [<ffffffff810b4395>] kswapd+0x2d3/0x2fd [<ffffffff81068049>] ? __wake_up_sync+0xd/0xd [<ffffffff810b40c2>] ? balance_pgdat+0x47f/0x47f [<ffffffff81051e75>] kthread+0xd6/0xde [<ffffffff81051d9f>] ? kthread_create_on_node+0x162/0x162 [<ffffffff813be5bc>] ret_from_fork+0x7c/0xb0 [<ffffffff81051d9f>] ? kthread_create_on_node+0x162/0x162 list_lru_walk_node() seems to be the only place where __count_vm_events() called with preemption enabled. remaining __count_vm_events() and __count_vm_event() calls are done with preemption disabled (unless I overlooked something). -ss -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html