process freeze (state *inp)

John Baldwin jhb at
Thu Aug 23 08:15:25 PDT 2007

On Monday 20 August 2007 09:12:18 am Julian D. Seifert wrote:
> Hi,
> I'm running an ircd (derived from unrealircd) on a FreeBSD 5.5-Release.
> Most times it runs totally okay but sometimes (not reproducable) 
> the process freezes with state "*inp" shown with "top".
> On no other operating system this problem occurs.
> (Linux 2.6.x and FreeBSD 6.2 and -Current) 
> When I googled for information I found this in the FAQ of unrealircd:
> I assume the bug they refer to is also present in 5.5-Rls and that this is
> the cause of the random freezes. I asked the unreal developers if they
> know any more specifics but they didn't. 
> Does anyone know what "tcp socket bug" they are referring to?
> I'm not so familiar with the FreeBSD kernel(and debugging it etc.)
> The simplest solution is probably to upgrade to 6.2 but I'd prefer fixing the
> bug for 5.5..
> (I forgot to mention that I formerly had 5.4-RLS installed and experienced the
>  same problem) 
> MfG,
> 	Julian D. `alamar` Seifert

The "*inp" state means that the thead is blocked on a mutex named "inp",
probably a lock for an inpcb (internet protocol control block: IP-specific
data about a socket).  The network stack locking had a _lot_ of changes in
6.x, and backporting them is probably very non-trivial.  I'd definitely
suggest updating to 6.2 (or even 6-stable) as there are many more bugs
fixed in 6.x whereas 5.x does not receive hardly any bug fixes at this

John Baldwin

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