Re: Deadlock, exclusive sx so_rcv_sx, amd64

On 25/10/2007, John Baldwin <jhb_at_freebsd.org> wrote:
> > Running rtorrent and ftp brings my system to a deadlock
> > in a few hours. Kernel still responds to pings and sends some
> > TCP acks.
...
> > Please suggest any other commands to run in DDB if needed.
> > Cores are saved.
>
> show sleepchain <pid>  will show if it's a real deadlock or not.
>

This time the freeze was a matter of minutes.

db> ps
  pid  ppid  pgrp   uid   state   wmesg         wchan        cmd
 1229   991   991     0  ?                                   smbd
 1201  1195  1201  1001  SL+     pfault   0xffffffff80b1359c rtorrent
 1199  1193  1199  1001  Ss+     ttyin    0xffffff0001211410 tcsh
 1197  1193  1197  1001  Ss+     ttyin    0xffffff0001218810 tcsh
 1195  1193  1195  1001  Ss+     pause    0xffffff000624a0c0 tcsh
 1193  1192  1193  1001  SLs     pfault   0xffffffff80b1359c screen
 1192  1190  1190  1001  S+      pause    0xffffff00013c10c0 screen
 1190  1189  1190  1001  Ss+     pause    0xffffff00065b40c0 tcsh
 1189  1187  1187  1001  S       select   0xffffffff80af79d0 sshd
 1187  1097  1187     0  Ss      sbwait   0xffffff00065346cc sshd
...

db> show alllocks
Process 1187 (sshd) thread 0xffffff00065ad350 (100166)
exclusive sx so_rcv_sx r = 0 (0xffffff0006534670) locked _at_
/usr/src/sys/kern/uipc_sockbuf.c:145

db> show sleepchain 1187
thread 100166 (pid 1187, sshd) sleeping on 0xffffff00065346cc "sbwait"
db> show sleepchain 1201
thread 100164 (pid 1201, rtorrent) sleeping on 0xffffffff80b1359c "pfault"

Nothing interesting I guess...
Maybe this is not a deadlock, what else can cause such a freeze?
I won't reboot it for a while -- maybe someone can suggest anything else.

-- 
With best regards, Gleb Kozyrev.