* FUTEX deadlock in ping?
@ 2005-02-24 10:14 Jörn Nettingsmeier
2005-02-24 12:07 ` bert hubert
2005-02-24 14:46 ` Olof Johansson
0 siblings, 2 replies; 5+ messages in thread
From: Jörn Nettingsmeier @ 2005-02-24 10:14 UTC (permalink / raw)
To: linux-kernel; +Cc: nettings
hi !
disclaimer: i'm not a kernel guy ;)
after reading the FUTEX deadlock thread
(http://thread.gmane.org/gmane.linux.kernel/280900), i was wondering:
ever since moving to ldap for passwd/group/shadow/hosts lookup, ping to
a non-reachable host just freezes up and never returns:
spunk:~ # strace ping herrnilsson
execve("/bin/ping", ["ping", "herrnilsson"], [/* 61 vars */]) = 0
uname({sys="Linux", node="spunk", ...}) = 0
brk(0) = 0x8063000
...
...
munmap(0x40504000, 4096) = 0
brk(0x80a5000) = 0x80a5000
uname({sys="Linux", node="spunk", ...}) = 0
futex(0x401540f4, FUTEX_WAIT, 2, NULL
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
is this one related to the FUTEX problem olof described?
best,
jörn
ps: i'd appreciate being cc:ed on replies. thanks.
for the record:
spunk:~ # uname -a
Linux spunk 2.6.8-24.11-smp #1 SMP Fri Jan 14 13:01:26 UTC 2005 i686
i686 i386 GNU/Linux
SuSE 9.2
problem happens also on ia32 UP (same version as before) and amd64 UP
(2.6.11-rc4-bk7)
ldap lookup is ok, for instance
spunk:~ # getent hosts herrnilsson
192.168.0.3 herrnilsson.villakunterbunt.netz herrnilsson
traceroute and others work as well.
on an otherwise identical system without ldap, ping correctly gives
"unreachable" messages.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: FUTEX deadlock in ping?
2005-02-24 10:14 FUTEX deadlock in ping? Jörn Nettingsmeier
@ 2005-02-24 12:07 ` bert hubert
2005-02-24 13:44 ` Joern Nettingsmeier
2005-02-24 14:46 ` Olof Johansson
1 sibling, 1 reply; 5+ messages in thread
From: bert hubert @ 2005-02-24 12:07 UTC (permalink / raw)
To: J?rn Nettingsmeier; +Cc: linux-kernel, nettings
On Thu, Feb 24, 2005 at 11:14:45AM +0100, J?rn Nettingsmeier wrote:
> ever since moving to ldap for passwd/group/shadow/hosts lookup, ping to
> a non-reachable host just freezes up and never returns:
>
> spunk:~ # strace ping herrnilsson
> execve("/bin/ping", ["ping", "herrnilsson"], [/* 61 vars */]) = 0
> uname({sys="Linux", node="spunk", ...}) = 0
> brk(0) = 0x8063000
> ...
> ...
> munmap(0x40504000, 4096) = 0
> brk(0x80a5000) = 0x80a5000
> uname({sys="Linux", node="spunk", ...}) = 0
> futex(0x401540f4, FUTEX_WAIT, 2, NULL
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Try ping -n. This is most likely something else.
--
http://www.PowerDNS.com Open source, database driven DNS Software
http://netherlabs.nl Open and Closed source services
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: FUTEX deadlock in ping?
2005-02-24 12:07 ` bert hubert
@ 2005-02-24 13:44 ` Joern Nettingsmeier
0 siblings, 0 replies; 5+ messages in thread
From: Joern Nettingsmeier @ 2005-02-24 13:44 UTC (permalink / raw)
To: bert hubert; +Cc: linux-kernel
hi bert!
thanks for your reply.
bert hubert wrote:
> On Thu, Feb 24, 2005 at 11:14:45AM +0100, J?rn Nettingsmeier wrote:
>
>
>>ever since moving to ldap for passwd/group/shadow/hosts lookup, ping to
>>a non-reachable host just freezes up and never returns:
>>
>>spunk:~ # strace ping herrnilsson
>>execve("/bin/ping", ["ping", "herrnilsson"], [/* 61 vars */]) = 0
>>uname({sys="Linux", node="spunk", ...}) = 0
>>brk(0) = 0x8063000
>>...
>>...
>>munmap(0x40504000, 4096) = 0
>>brk(0x80a5000) = 0x80a5000
>>uname({sys="Linux", node="spunk", ...}) = 0
>>futex(0x401540f4, FUTEX_WAIT, 2, NULL
>>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
>
> Try ping -n. This is most likely something else.
>
hmm. ping -n would still have to look up the hostname, and indeed the
strace is identical (hanging). but when i ping the ip (this is probably
what you had in mind), it works as expected.
anyway, why would a process block endlessly in a futex?
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: FUTEX deadlock in ping?
2005-02-24 10:14 FUTEX deadlock in ping? Jörn Nettingsmeier
2005-02-24 12:07 ` bert hubert
@ 2005-02-24 14:46 ` Olof Johansson
2005-02-24 14:56 ` Jörn Nettingsmeier
1 sibling, 1 reply; 5+ messages in thread
From: Olof Johansson @ 2005-02-24 14:46 UTC (permalink / raw)
To: Jörn Nettingsmeier; +Cc: linux-kernel, nettings
On Thu, Feb 24, 2005 at 11:14:45AM +0100, Jörn Nettingsmeier wrote:
> futex(0x401540f4, FUTEX_WAIT, 2, NULL
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> is this one related to the FUTEX problem olof described?
As bert said, it's likely something else. Is the process killable, and
does "ps aux" complete? If so, then this is a different problem.
-Olof
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: FUTEX deadlock in ping?
2005-02-24 14:46 ` Olof Johansson
@ 2005-02-24 14:56 ` Jörn Nettingsmeier
0 siblings, 0 replies; 5+ messages in thread
From: Jörn Nettingsmeier @ 2005-02-24 14:56 UTC (permalink / raw)
To: Olof Johansson; +Cc: linux-kernel, nettings
Olof Johansson wrote:
> On Thu, Feb 24, 2005 at 11:14:45AM +0100, Jörn Nettingsmeier wrote:
>
>
>>futex(0x401540f4, FUTEX_WAIT, 2, NULL
>>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>
>>is this one related to the FUTEX problem olof described?
>
>
> As bert said, it's likely something else. Is the process killable, and
> does "ps aux" complete?
yes and yes.
> If so, then this is a different problem.
too bad. i thought i had finally found a clue.. sorry for the noise, and
many thanks for explaining!
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2005-02-24 15:39 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-02-24 10:14 FUTEX deadlock in ping? Jörn Nettingsmeier
2005-02-24 12:07 ` bert hubert
2005-02-24 13:44 ` Joern Nettingsmeier
2005-02-24 14:46 ` Olof Johansson
2005-02-24 14:56 ` Jörn Nettingsmeier
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).