Re: Firefox hangs in state 'kqread'

[Laurent Sartran <lsartran@xxxxxxxxxx>]

On Sun, 13 Mar 2005 13:06:38 -0800 (PST), Matthew Dillon wrote:
>     If this is repeatable, use netstat to see if firefox (or whatever) is
>     stuck on trying to make a TCP connection or something like that.
> 
>     Also ktrace the process looking specifically for the trace of what happens
>     when firefox *RECOVERS* (i.e. does it suddenly get a connection timeout
>     return from a descriptor or something like that).
> 
> 						-Matt

The problem is very easy to reproduce by loading a big number of different 
sites in different tabs at the same time. I loaded every result returned 
by Google about "dragonfly bsd", and the browser froze just a few seconds 
after that.

Here is the trace of the process before and after the hang:

     958 opera    CALL  socket(0x2,0x2,0)
     958 opera    RET   socket 100/0x64
     958 opera    CALL  fcntl(0x64,0x3,0)
     958 opera    RET   fcntl 2
     958 opera    CALL  fcntl(0x64,0x4,0x6)
     958 opera    RET   fcntl 0
     958 opera    CALL  connect(0x64,0x28e8d8f0,0x10)
     958 opera    RET   connect 0
     958 opera    CALL  sendto(0x64,0x988c000,0x24,0,0,0)
     958 opera    GIO   fd 100 wrote 36 bytes
         "\M^Y8\^A\0\0\^A\0\0\0\0\0\0\^Bad\vdoubleclick\^Cnet\0\0\^\\0\^A"
     958 opera    RET   sendto 36/0x24
     958 opera    CALL  gettimeofday(0xbfadc688,0)
     958 opera    RET   gettimeofday 0
     958 opera    CALL  kevent(0x63,0xbfadc6ac,0x1,0xbfadc6ac,0x1,0xbfadc690)
(the browser hangs in "kqread" state... then recovers)
     958 opera    RET   kevent 0
     958 opera    CALL  fstat(0x64,0xbfadc59c)
     958 opera    RET   fstat 0
     958 opera    CALL  close(0x64)
     958 opera    RET   close 0
     958 opera    CALL  socket(0x2,0x2,0)
     958 opera    RET   socket 100/0x64
     958 opera    CALL  fcntl(0x64,0x3,0)
     958 opera    RET   fcntl 2
     958 opera    CALL  fcntl(0x64,0x4,0x6)
     958 opera    RET   fcntl 0

And the output of netstat -n during a hang
(192.168.0.2 is my machine, and 192.168.0.1 is the gateway) :

Active Internet connections
Proto Recv-Q Send-Q Local Address         Foreign Address       (state)
tcp4       0      0 192.168.0.2.1422      205.206.231.15.80     SYN_SENT
tcp4       0      0 192.168.0.2.1421      217.16.20.116.80      SYN_SENT
tcp4       0      0 192.168.0.2.1420      194.67.45.100.80      ESTABLISHED
tcp4       0      0 192.168.0.2.1419      194.67.35.191.80      ESTABLISHED
tcp4       0    514 192.168.0.2.1418      81.19.66.65.80        ESTABLISHED
tcp4       0    519 192.168.0.2.1417      81.19.66.19.80        ESTABLISHED
tcp4       0    525 192.168.0.2.1416      81.19.66.82.80        ESTABLISHED
tcp4    1553      0 192.168.0.2.1415      81.9.34.200.80        CLOSE_WAIT
tcp4       0      0 192.168.0.2.1414      205.206.231.15.80     LAST_ACK
tcp4       0      0 192.168.0.2.1413      217.16.20.116.80      LAST_ACK
tcp4       0      0 192.168.0.2.1412      81.222.128.12.80      CLOSE_WAIT
tcp4       0      0 192.168.0.2.1411      199.201.233.88.80     ESTABLISHED
tcp4       0      0 192.168.0.2.1408      199.201.233.88.80     TIME_WAIT
tcp4       0      0 192.168.0.2.1406      205.206.231.15.80     TIME_WAIT
tcp4       0      0 192.168.0.2.1402      66.102.11.104.80      ESTABLISHED
tcp4       0      0 192.168.0.2.1401      216.154.201.125.80    ESTABLISHED
tcp4       0      0 192.168.0.2.1400      207.142.131.245.80    CLOSE_WAIT
tcp4       0      0 192.168.0.2.1398      66.102.11.104.80      TIME_WAIT
tcp4       0      0 192.168.0.2.1397      66.67.215.79.80       ESTABLISHED
tcp4       0      0 192.168.0.2.1374      81.173.4.8.80         TIME_WAIT
tcp4       0      0 192.168.0.2.1368      204.152.186.140.80    TIME_WAIT
tcp4       0      0 192.168.0.2.1364      66.179.48.110.80      ESTABLISHED
tcp4       0      0 192.168.0.2.1362      81.173.4.8.80         TIME_WAIT
tcp4       0      0 192.168.0.2.1349      193.254.241.218.80    TIME_WAIT
tcp4       0      0 192.168.0.2.1347      140.112.30.75.80      TIME_WAIT
tcp4       0      0 192.168.0.2.1346      65.19.132.39.80       TIME_WAIT
tcp4       0      0 192.168.0.2.1345      66.102.9.99.80        ESTABLISHED
tcp4       0      0 192.168.0.2.1343      10.0.4.166.80         SYN_SENT
tcp4       0      0 192.168.0.2.1294      216.170.12.234.80     LAST_ACK
tcp4       0      0 127.0.0.1.25          *.*                   LISTEN
udp4       0      0 192.168.0.2.1451      192.168.0.1.53        
Active UNIX domain sockets
Address  Type   Recv-Q Send-Q    Inode     Conn     Refs  Nextref Addr
[snip]

I hope this may be useful to find where the problem is...
If there is anything else I can do to help, please let me know.

Regards,

Laurent Sartran