[Dovecot] Kernel warnings

[Thomas Zajic]

* Timo Sirainen, 2010-01-02 17:48

> On 2.1.2010, at 3.45, Thomas Zajic wrote:
> 
>> [<c1095367>] ? inotify_free_group_priv+0x12/0x21
>> [<c1093c81>] ? fsnotify_final_destroy_group+0x16/0x1e
> ..
>> There are no processes other than dovecot's "imap" that are ever causing
>> these warnings. Does this indicate a problem in the kernel or rather in
>> dovecot?
> 
> Yes.

Hehe ... okay, so which one is it? :-) I don't even know what exactly
to make of this warning - obviously, there may be a potential memory
leak related to inotify and dovecot's imap process, but is it

1. a bug in the kernel that is triggered by something that dovecot's
   inotify code does, or

2. a bug in dovecot's imap that the kernel notices and warns about as
   of 2.6.31 (but didn't notice and/or warn about in 2.6.30 and earlier)?

> The reason why only imap process creates these is because it's probably
> the only process using inotify. You could of course compile Dovecot
> without inotify support, but that's just a workaround..

Hmmm ... I don't mind the warning as such, as it doesn't have any
actual bad side effects as far as I can tell, I'm just curious as
to what causes it.

Is there anything related I should/could tune in /proc/sys/fs/inotify?

[root at airframe]:~# grep -r . /proc/sys/fs/inotify
/proc/sys/fs/inotify/max_user_instances:128
/proc/sys/fs/inotify/max_user_watches:65536
/proc/sys/fs/inotify/max_queued_events:16384
[root at airframe]:~# 

Bye,
Thomas