From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: divide by 0 error in igbvf_set_coalesce - ab50a2a Date: Mon, 18 Jun 2012 12:16:13 -0600 Message-ID: <4FDF706D.7080509@cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: mitch.a.williams@intel.com Return-path: Received: from mtv-iport-3.cisco.com ([173.36.130.14]:48662 "EHLO mtv-iport-3.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751629Ab2FRSQP (ORCPT ); Mon, 18 Jun 2012 14:16:15 -0400 Sender: netdev-owner@vger.kernel.org List-ID: Mitch: I have a VM using a 82576 based VF. Running: $ ethtool -C eth2 rx-usecs 0 generates the following trace on console: [ 894.683322] divide error: 0000 [#1] SMP [ 894.684020] CPU 1 [ 894.684020] Modules linked in: sunrpc virtio_net igbvf virtio_blk virtio_pci virtio_ring virtio [ 894.684020] [ 894.684020] Pid: 7310, comm: ethtool Not tainted 3.5.0-rc1 #0 Bochs Bochs [ 894.684020] RIP: 0010:[] [] igbvf_set_coalesce+0x5b/0x8b [igbvf] [ 894.684020] RSP: 0018:ffff88003cd51c38 EFLAGS: 00010246 [ 894.684020] RAX: 000000003b9aca00 RBX: ffff88003aa42000 RCX: 0000000000000000 [ 894.684020] RDX: 0000000000000000 RSI: ffff88003cd51c48 RDI: ffff88003aa42780 [ 894.684020] RBP: ffff88003cd51c38 R08: 0000000000000000 R09: 0000000000000000 [ 894.684020] R10: 0000000000000000 R11: ffff88003cd51ec8 R12: ffff88003cd51c48 [ 894.684020] R13: 000000000000000f R14: 00000000ffffffff R15: 00000000fffffff2 [ 894.684020] FS: 00007f8142ccb720(0000) GS:ffff88003fd00000(0000) knlGS:0000000000000000 [ 894.684020] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 894.684020] CR2: 000000000040466c CR3: 000000003c754000 CR4: 00000000000007e0 [ 894.684020] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 894.684020] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 894.684020] Process ethtool (pid: 7310, threadinfo ffff88003cd50000, task ffff88003b984470) [ 894.684020] Stack: [ 894.684020] ffff88003cd51cb8 ffffffff8132bcf5 000000000000000f 0000000000000000 [ 894.684020] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 894.684020] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 894.684020] Call Trace: [ 894.684020] [] ethtool_set_coalesce+0x54/0x5d [ 894.684020] [] dev_ethtool+0x5dc/0x175b [ 894.684020] [] ? need_resched+0x1e/0x28 [ 894.684020] [] ? should_resched+0x9/0x29 [ 894.684020] [] ? _cond_resched+0xe/0x22 [ 894.684020] [] dev_ioctl+0x517/0x684 [ 894.684020] [] ? pmd_offset+0x14/0x3b [ 894.684020] [] sock_do_ioctl+0x3d/0x48 [ 894.684020] [] sock_ioctl+0x1f8/0x207 [ 894.684020] [] do_vfs_ioctl+0x475/0x4b6 [ 894.684020] [] ? inode_has_perm.clone.19.clone.27+0x33/0x35 [ 894.684020] [] ? file_has_perm+0x73/0x7e [ 894.684020] [] ? fd_install+0x57/0x60 [ 894.684020] [] sys_ioctl+0x56/0x79 [ 894.684020] [] system_call_fastpath+0x16/0x1b [ 894.684020] Code: 83 f8 02 77 0f c7 87 0c 03 00 00 e8 01 00 00 8b 46 04 eb 19 8d 04 8d 00 00 00 00 31 d2 89 87 0c 03 00 00 c1 e1 0a b8 00 ca 9a 3b f1 89 87 08 03 00 00 8b 97 0c 03 00 00 48 8b 87 80 03 00 00 [ 894.684020] RIP [] igbvf_set_coalesce+0x5b/0x8b [igbvf] [ 894.684020] RSP [ 894.779474] ---[ end trace 162bed6b66df758d ]--- This commit introduced the problem: commit ab50a2a430693b0961dc7b7d9fe2a4bd77d11ea6 Author: Mitch A Williams Date: Sat Jan 14 08:10:50 2012 +0000 igbvf: refactor Interrupt Throttle Rate code David