https://bugzilla.kernel.org/show_bug.cgi?id=67751 Bug ID: 67751 Summary: Stack trace with suspicious RCU usage, when starting ovs-switchd Product: Virtualization Version: unspecified Kernel Version: 3.13.0-0.rc4.git5.1.fc21.x86_64 Hardware: All OS: Linux Tree: Fedora Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: kashyap.cv@xxxxxxxxx Regression: No I see the below on serial console of a Fedora-20 virtual machine when I boot into Kernel 3.13.0-0.rc4.git5.1.fc21.x86_64: --------------------- . . . [ 26.327387] [ 26.328384] =============================== [ 26.330206] [ INFO: suspicious RCU usage. ] [ 26.332044] 3.13.0-0.rc4.git5.1.fc21.x86_64 #1 Not tainted [ 26.334460] ------------------------------- [ 26.336286] net/openvswitch/flow_table.c:436 suspicious rcu_dereference_check() usage! [ 26.339609] [ 26.339609] other info that might help us debug this: [ 26.339609] [ 26.342996] [ 26.342996] rcu_scheduler_active = 1, debug_locks = 0 [ 26.345794] 2 locks held by ovs-vswitchd/720: [ 26.347643] #0: (cb_lock){++++++}, at: [<ffffffff816535c9>] genl_rcv+0x19/0x40 [ 26.351695] #1: (ovs_mutex){+.+.+.}, at: [<ffffffffa0187dc9>] ovs_flow_cmd_new_or_set+0xf9/0x600 [openvswitch] [ 26.356970] [ 26.356970] stack backtrace: [ 26.358825] CPU: 1 PID: 720 Comm: ovs-vswitchd Not tainted 3.13.0-0.rc4.git5.1.fc21.x86_64 #1 [ 26.362207] Hardware name: Red Hat KVM, BIOS Bochs 01/01/2011 [ 26.364499] 0000000000000001 ffff880499af37e0 ffffffff8175b6d2 ffff8800da5ab3a0 [ 26.368323] ffff880499af3810 ffffffff810cd2f7 ffff8804a29c9ea0 ffff880499af387c [ 26.372140] ffff8804986f8a10 ffff8804986f89f0 ffff880499af3860 ffffffffa018f608 [ 26.375929] Call Trace: [ 26.377070] [<ffffffff8175b6d2>] dump_stack+0x4d/0x66 [ 26.379340] [<ffffffff810cd2f7>] lockdep_rcu_suspicious+0xe7/0x120 [ 26.381818] [<ffffffffa018f608>] ovs_flow_tbl_lookup+0x188/0x1b0 [openvswitch] [ 26.384835] [<ffffffffa0187e06>] ovs_flow_cmd_new_or_set+0x136/0x600 [openvswitch] [ 26.387961] [<ffffffff816552c1>] ? genl_family_rcv_msg+0x2c1/0x370 [ 26.390506] [<ffffffff8165518d>] genl_family_rcv_msg+0x18d/0x370 [ 26.393025] [<ffffffff81655370>] ? genl_family_rcv_msg+0x370/0x370 [ 26.395811] [<ffffffff816553fe>] genl_rcv_msg+0x8e/0xd0 [ 26.398045] [<ffffffff81653079>] netlink_rcv_skb+0xa9/0xc0 [ 26.400416] [<ffffffff816535d8>] genl_rcv+0x28/0x40 [ 26.402561] [<ffffffff816526a5>] netlink_unicast+0xd5/0x1a0 [ 26.404971] [<ffffffff81652aa7>] netlink_sendmsg+0x337/0x750 [ 26.407294] [<ffffffff81600cab>] sock_sendmsg+0x8b/0xc0 [ 26.409646] [<ffffffff811a7dbf>] ? might_fault+0x5f/0xb0 [ 26.411851] [<ffffffff811a7e08>] ? might_fault+0xa8/0xb0 [ 26.414103] [<ffffffff811a7dbf>] ? might_fault+0x5f/0xb0 [ 26.416280] [<ffffffff81610a5e>] ? verify_iovec+0x5e/0xe0 [ 26.418645] [<ffffffff81601109>] ___sys_sendmsg+0x3d9/0x3f0 [ 26.421138] [<ffffffff810575e7>] ? kvm_clock_read+0x27/0x40 [ 26.423483] [<ffffffff81021a59>] ? sched_clock+0x9/0x10 [ 26.425726] [<ffffffff810b64cd>] ? sched_clock_local+0x1d/0x80 [ 26.428104] [<ffffffff810b6658>] ? sched_clock_cpu+0xa8/0x100 [ 26.430515] [<ffffffff810cb4cd>] ? trace_hardirqs_off+0xd/0x10 [ 26.432914] [<ffffffff810b679f>] ? local_clock+0x5f/0x70 [ 26.435118] [<ffffffff810cc07f>] ? lock_release_holdtime.part.29+0xf/0x190 [ 26.439405] [<ffffffff8121c85d>] ? fget_light+0xed/0x4f0 [ 26.441705] [<ffffffff8121c7ac>] ? fget_light+0x3c/0x4f0 [ 26.444102] [<ffffffff81602662>] __sys_sendmsg+0x42/0x80 [ 26.446293] [<ffffffff816026b2>] SyS_sendmsg+0x12/0x20 [ 26.448435] [<ffffffff8176e329>] system_call_fastpath+0x16/0x1b . . . --------------------- [This virtual machine has Open vSwitch daemon and a bunch of other OpenStack networking components running.] I filed this here first -- https://bugzilla.redhat.com/show_bug.cgi?id=1046286 -- You are receiving this mail because: You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
