Re: [bug] stuck localhost TCP connections, v2.6.26-rc3+

From: HÃkon LÃvdal
Date: Sat May 31 2008 - 13:58:51 EST


Ilpo JÃrvinen wrote:
Hmm, are the other end's processes still there? ...I'd be interested to know what they're doing at the moment...

I meant that end where you see this '-'. I suppose it's easy for you to
figure out which process is the right one, something that wouldn't be so
easy with the Ingo's test case which forks/exits numerous times.

Died? Do you mean that they don't exist all at the other end anymore?

The ssh connection used for copying (using the command <ssh old_pc "cd
/directory; tar cvf - *" | pv | tar xvf ->) died in the following way:
...
Read from remote host old_pc: Connection timed out
51.4GB 4:26:19 [3.29MB/s] [<=> ]
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now

and there are currently no traces of those ssh processes any longer on
the new PC, only these two active ssh interactive connections are present:

new_pc>ps -elf | sed -n '1p;/ssh/p'
F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD
0 S hlovdal 1310 1195 0 80 0 - 14139 select 09:28 pts/14 00:00:00 ssh old_pc
5 S root 2477 1 0 80 0 - 15203 - May26 ? 00:00:00 /usr/sbin/sshd
1 S hlovdal 2727 2701 0 80 0 - 12466 select May26 ? 00:00:00 /usr/bin/ssh-agent /bin/sh -c exec -l /bin/bash -c "/usr/bin/startkde"
0 S hlovdal 26436 19976 0 80 0 - 20375 pipe_w 19:43 pts/9 00:00:00 sed -n 1p;/ssh/p
0 S hlovdal 30065 18970 0 80 0 - 14174 select May28 pts/6 00:00:00 ssh old_pc
new_pc>

On the old PC there are three corresponding zombies:

old_pc>ps -elf | sed -n '1p;/ssh/p'
F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD
5 S root 4402 1 0 80 0 - 1600 - May25 ? 00:00:02 /usr/sbin/sshd
1 S root 5418 1 0 80 0 - 1347 - May25 ? 00:00:00 ssh-agent
1 S hlovdal 5752 1 0 80 0 - 1347 - May25 ? 00:00:00 ssh-agent
4 S root 6824 4402 0 80 0 - 2315 - 09:28 ? 00:00:00 sshd: hlovdal [priv]
5 S hlovdal 6828 6824 0 80 0 - 2355 - 09:28 ? 00:00:01 sshd: hlovdal@pts/8
0 S hlovdal 17186 25557 0 80 0 - 1191 - 19:45 pts/0 00:00:00 sed -n 1p;/ssh/p
4 D root 24444 4402 0 80 0 - 0 - May27 ? 00:00:00 [sshd]
5 Z hlovdal 24448 24444 0 80 0 - 0 - May27 ? 00:58:33 [sshd] <defunct>
4 S root 25552 4402 0 80 0 - 2315 - May28 ? 00:00:00 sshd: hlovdal [priv]
5 S hlovdal 25556 25552 0 80 0 - 2383 - May28 ? 00:00:01 sshd: hlovdal@pts/0
1 S hlovdal 28504 28328 0 80 0 - 1347 - May28 ? 00:00:01 /usr/bin/ssh-agent /usr/bin/dbus-launch --exit-with-session /usr/bin/startkde
4 D root 31338 4402 0 80 0 - 0 - May27 ? 00:00:00 [sshd]
5 Z hlovdal 31342 31338 0 80 0 - 0 - May27 ? 00:07:55 [sshd] <defunct>
4 D root 31564 4402 0 80 0 - 0 - May27 ? 00:00:00 [sshd]
5 Z hlovdal 31568 31564 0 80 0 - 0 - May27 ? 00:43:53 [sshd] <defunct>
old_pc>


I can post output from /proc/net/tcp

For both ends that would be great.

111111AC is the old PC.
480111AC is the new PC.

new_pc>sed -n '1p; /:0016/p' /proc/net/tcp
sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode
3: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 8850 1 ffff81022ddd2680 3000 0 0 2 -1
7: 480111AC:AB31 111111AC:0016 01 00000000:00000000 02:000A2A2B 00000000 500 0 138582 2 ffff81022d9d7380 202 40 22 3 -1
8: 480111AC:CDBB 111111AC:0016 01 00000000:00000000 02:0001BBAD 00000000 500 0 723741 2 ffff81017560c000 202 40 18 3 -1
new_pc>


old_pc>sed -n '1p; /:0016/p' /proc/net/tcp
sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode
12: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 7627 1 f384b080 3000 0 0 2 -1
17: 111111AC:0016 480111AC:CDBB 01 00000000:00000000 02:0001AA7B 00000000 0 0 1110320 2 f02e6580 201 53 7 3 -1
20: 111111AC:0016 480111AC:AB31 01 00000000:00000000 02:000A18F1 00000000 0 0 583506 4 f71a8080 201 40 29 3 -1
21: 111111AC:0016 480111AC:E4E9 01 00000B50:00000000 01:7D1F8746 00000000 0 0 398713 5 f71a8580 205 40 1 36 -1
23: 111111AC:0016 480111AC:D359 01 000010F8:00000000 01:7D19A035 00000000 0 0 396426 5 f71a8a80 202 42 1 144 -1
25: 111111AC:0016 480111AC:8565 01 00000B50:00000000 01:7CEBA7D1 00000000 0 0 349113 5 eeeaf580 204 40 1 26 -1
old_pc>


BR HÃkon LÃvdal


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