Re: huh, entered softirq 3 NET_RX 082db810 preempt_count 00000101, exited with fffefc05?
flat view
From: Cong Wang <hidden>
Date: 2012-10-29 08:09:13
On Fri, 26 Oct 2012 at 20:34 GMT, Toralf Förster [off-list ref] wrote:
At a user mode linux image (unstable Gentoo) I experienced a hang (100% CPU of the linux process), no reaction anymore. The last lines in the syslog of the UML gave: ... Oct 26 22:18:07 n22_uml kernel: Virtual console 6 assigned device '/dev/pts/5' Oct 26 22:18:07 n22_uml kernel: Virtual console 4 assigned device '/dev/pts/6' Oct 26 22:18:07 n22_uml kernel: Virtual console 5 assigned device '/dev/pts/8' Oct 26 22:18:07 n22_uml kernel: Virtual console 3 assigned device '/dev/pts/9' Oct 26 22:18:07 n22_uml kernel: Virtual console 2 assigned device '/dev/pts/10' Oct 26 22:18:07 n22_uml kernel: Virtual console 1 assigned device '/dev/pts/11' Oct 26 22:19:05 n22_uml kernel: ------------[ cut here ]------------ Oct 26 22:19:05 n22_uml kernel: WARNING: at kernel/softirq.c:160 local_bh_enable+0x8f/0xa0() Oct 26 22:19:05 n22_uml kernel: 384fa37c: [<0836bc48>] dump_stack+0x22/0x24 Oct 26 22:19:05 n22_uml kernel: 384fa394: [<0807fc2a>] warn_slowpath_common+0x5a/0x80 Oct 26 22:19:05 n22_uml kernel: 384fa3bc: [<0807fd03>] warn_slowpath_null+0x23/0x30 Oct 26 22:19:05 n22_uml kernel: 384fa3cc: [<0808733f>] local_bh_enable+0x8f/0xa0 Oct 26 22:19:05 n22_uml kernel: 384fa3e0: [<082da6f8>] dev_queue_xmit+0xe8/0x270 Oct 26 22:19:05 n22_uml kernel: 384fa410: [<082fd15f>] ip_finish_output+0x1af/0x370 Oct 26 22:19:05 n22_uml kernel: 384fa444: [<082fd373>] ip_output+0x53/0x60 Oct 26 22:19:05 n22_uml kernel: 384fa45c: [<082fc243>] ip_local_out+0x23/0x30 Oct 26 22:19:05 n22_uml kernel: 384fa46c: [<082fc384>] ip_build_and_send_pkt+0x134/0x1f0 Oct 26 22:19:05 n22_uml kernel: 384fa4a8: [<08319dc0>] tcp_v4_conn_request+0x7c0/0xcc0
Seems we want to send some packet inside tcp_v4_conn_request() while we just receive one in softIRQ, not sure why we defer it. Thanks.