From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ross Lagerwall Subject: Re: Linux 4.2-rc5: Date: Mon, 10 Aug 2015 10:00:11 +0100 Message-ID: <55C8681B.6030700@citrix.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: linux@eikelenboom.it, David Vrabel Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 08/06/2015 08:51 PM, linux@eikelenboom.it wrote: > Hi Ross, > > On my dom0 with a linux 4.2-rc5 kernel i encoutered the splat below. > It's probably related to your patch that went in just for 4.2-rc5: > "xen/events/fifo: Handle linked events when closing a port" > > -- > Sander > > [ 49.020173] ------------[ cut here ]------------ > [ 49.020187] WARNING: CPU: 0 PID: 1 at > drivers/xen/events/events_fifo.c:395 evtchn_fifo_close+0xbd/0xc0() > [ 49.020191] Modules linked in: > [ 49.020198] CPU: 0 PID: 1 Comm: swapper/0 Not tainted > 4.2.0-rc5-20150804-linus-doflr+ #1 > [ 49.020200] Hardware name: MSI MS-7640/890FXA-GD70 (MS-7640) , BIOS > V1.8B1 09/13/2010 > [ 49.020208] ffffffff81faaae8 ffff880059b9bad8 ffffffff81aed513 > 0000000000000000 > [ 49.020214] 0000000000000000 ffff880059b9bb18 ffffffff810c7280 > 0000000000000041 > [ 49.020219] 0000000000000041 0000000000000000 ffff880059807ca8 > ffff880059807c00 > [ 49.020220] Call Trace: > [ 49.020233] [] dump_stack+0x45/0x57 > [ 49.020240] [] warn_slowpath_common+0x80/0xc0 > [ 49.020245] [] warn_slowpath_null+0x15/0x20 > [ 49.020249] [] evtchn_fifo_close+0xbd/0xc0 > [ 49.020278] [] xen_evtchn_close+0x1d/0x60 > [ 49.020281] [] ? irq_get_irq_data+0x9/0x20 > [ 49.020282] [] shutdown_pirq+0x4b/0x70 > [ 49.020283] [] irq_shutdown+0x34/0x70 > [ 49.020285] [] __free_irq+0x19d/0x1e0 > [ 49.020286] [] free_irq+0x48/0xb0 > [ 49.020287] [] i8042_probe+0x38f/0x693 > [ 49.020291] [] platform_drv_probe+0x2f/0x90 > [ 49.020292] [] driver_probe_device+0x1af/0x2d0 > [ 49.020293] [] __driver_attach+0x8b/0x90 > [ 49.020294] [] ? driver_probe_device+0x2d0/0x2d0 > [ 49.020296] [] bus_for_each_dev+0x5f/0x90 > [ 49.020297] [] driver_attach+0x19/0x20 > [ 49.020298] [] bus_add_driver+0x1ab/0x220 > [ 49.020299] [] driver_register+0x5b/0xe0 > [ 49.020300] [] __platform_driver_register+0x45/0x50 > [ 49.020301] [] __platform_driver_probe+0x31/0xe0 > [ 49.020303] [] __platform_create_bundle+0xa3/0xd0 > [ 49.020304] [] ? i8042_toggle_aux+0x6c/0x6c > [ 49.020305] [] ? i8042_probe+0x693/0x693 > [ 49.020306] [] i8042_init+0x3d0/0x3f6 > [ 49.020308] [] do_one_initcall+0x87/0x1d0 > [ 49.020310] [] kernel_init_freeable+0x1db/0x263 > [ 49.020312] [] ? rest_init+0x80/0x80 > [ 49.020314] [] kernel_init+0x9/0xe0 > [ 49.020315] [] ret_from_fork+0x3f/0x70 > [ 49.020317] [] ? rest_init+0x80/0x80 > [ 49.020320] ---[ end trace 64c385518fcbbfa1 ]--- > Thanks. This means that the event channel is being closed with interrupts disabled, so it cannot guarantee that the event is not linked in. This is not a regression in behavior -- previously this was _never_ guaranteed and just silently ignored. However, we should find a way to fix this completely, to avoid warning spam. Regards, -- Ross Lagerwall