From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergey Senozhatsky Subject: kswapd using __this_cpu_add() in preemptible code Date: Tue, 18 Mar 2014 21:53:30 +0300 Message-ID: <20140318185329.GB430@swordfish> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , Mel Gorman , Michal Hocko , Rik van Riel , Johannes Weiner , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org To: Alexander Viro Return-path: Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org 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: [] dump_stack+0x4e/0x7a [] check_preemption_disabled+0xce/0xdd [] __this_cpu_preempt_check+0x2b/0x2d [] inode_lru_isolate+0xed/0x197 [] list_lru_walk_node+0x7b/0x14c [] ? iput+0x131/0x131 [] prune_icache_sb+0x35/0x4c [] super_cache_scan+0xe3/0x143 [] shrink_slab_node+0x103/0x16f [] shrink_slab+0x75/0xe4 [] balance_pgdat+0x2fa/0x47f [] kswapd+0x2d3/0x2fd [] ? __wake_up_sync+0xd/0xd [] ? balance_pgdat+0x47f/0x47f [] kthread+0xd6/0xde [] ? kthread_create_on_node+0x162/0x162 [] ret_from_fork+0x7c/0xb0 [] ? 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org