[lxc-devel] [PATCH] tests: Introduce lxc-test-concurrent for testing basic actions concurrently

[Dwight Engen]

On Fri, 13 Sep 2013 12:09:55 -0400
S.Çağlar Onur <caglar at 10ur.org> wrote:

> Hi Dwight,
> 
> Yes, I only observed a hang so far but not this assertion (in fact I
> don't remember ever seeing that). What I'm seeing is this;

Okay, something funny is going on, but I don't know what yet. That
assertion is coming from liblxc.so->libgnutls->libgcrypt and seems to
be complaining that we're unlocking something that is already unlocked.
So I compiled lxc without GNUTLS support (by commenting out the check
for it in configure.ac) and now I get past that and get hangs similar to
yours.

Interestingly, I modified your program to just do the create and
destroy and not the start nor stop and I still get the hangs during the
creation part.

> * lxc-test-concurrent get stuck
> 
> [caglar at qgq:~] sudo lxc-test-concurrent
> Executing (create) for 5 containers...
> 
> * ps auwxf shows this (so no rsync etc. running anymore)
> 
> caglar   21004  0.2  0.2  51344  4868 ?        S    11:59   0:00
> mosh-server new -s -c 256 -l LANG=en_US.UTF-8
> caglar   21005  0.0  0.2  23068  4412 pts/2    Ss   11:59   0:00  \_
> -bash root     27347  0.0  0.1  60248  2080 pts/2    S+   12:03
> 0:00      \_ sudo lxc-test-concurrent
> root     27348  0.0  0.0 383816   884 pts/2    Sl+  12:03   0:00
>  \_ lxc-test-concurrent
> root     27354  0.0  0.0 381684   408 pts/2    S+   12:03   0:00
>    \_ lxc-test-concurrent
> 
> * strace give this
> 
> [caglar at qgq:~/Projects/lxc(staging)] sudo strace -p 27354
> Process 27354 attached - interrupt to quit
> futex(0x7fdc68b82cc0, FUTEX_WAIT_PRIVATE, 2, NULL^C <unfinished ...>
> Process 27354 detached
> [caglar at qgq:~/Projects/lxc(staging)] sudo strace -p 27348
> Process 27348 attached - interrupt to quit
> futex(0x7fdc65f3d9d0, FUTEX_WAIT, 27353, NULL^C <unfinished ...>
> Process 27348 detached
> [caglar at qgq:~/Projects/lxc(staging)] sudo strace -p 27347
> Process 27347 attached - interrupt to quit
> select(6, [3 5], [], NULL, NULL^C <unfinished ...>
> Process 27347 detached
> 
> * lxc-ls
> 
> [caglar at qgq:~/Projects/lxc(staging)] sudo lxc-ls --fancy
> NAME       STATE    IPV4  IPV6
> ------------------------------
> 0          STOPPED  -     -
> 1          STOPPED  -     -
> 2          STOPPED  -     -
> 3          STOPPED  -     -
> 4          STOPPED  -     -
> 
> * /var/lib/lxc/4/partial still there
> 
> [caglar at qgq:/var/lib/lxc] ls /var/lib/lxc/*
> /var/lib/lxc/lxc-monitord.log
> 
> /var/lib/lxc/0:
> config  fstab  rootfs
> 
> /var/lib/lxc/1:
> config  fstab  rootfs
> 
> /var/lib/lxc/2:
> config  fstab  rootfs
> 
> /var/lib/lxc/3:
> config  fstab  rootfs
> 
> /var/lib/lxc/4:
> config  partial  rootfs
> 
> /var/lib/lxc/bleach:
> config  fstab  lxc_snapshots  rootfs
> 
> /var/lib/lxc/bleach-ng:
> config  delta0  fstab  lxc_rdepends  rootfs
> ​