[Freeswitch-users] A possible bug in FS causing Linux Kernel crash

[Giovanni Maruzzelli]

Ciao Muhammad,

I've got many problems with ALSA drivers, including various kind of crashes.

To make a looong story short, use the alsa_drivers version 1.0.20,
they have not yet crashed on me.

Also, if you want to test it, you can compile the customized snd-dummy
driver you find in the svn code, it is a try to have much more
efficiency bot in softirqs and context switches, allows for 64 Skype
instances (128 subdevices), etc. it is to be compiled with
alsa_drivers 1.0.20 too.

Is my feeling (I mean, almost sure) they got spin_locking wrong in
previous versions, and it crashes the kernel when you "really" use it
(Skype clients have a demented usage of alsa).

BTW, I'm in the process of revamp the code, fix the bugs and apply
patches. Please, have a look at the new wiki page with lots of new
content, I'll send a mail to the ML tomorrow :-)


Sincerely,

Giovanni Maruzzelli
=========================================
www.celliax.org
via Pierlombardo 9, 20135 Milano
Italy
gmaruzz at celliax dot org
Cell : +39-347-2665618
Fax : +39-02-87390039




On Sun, Jul 26, 2009 at 2:19 PM, Muhammad
Shahzad<shaheryarkh at googlemail.com> wrote:
> Hi,
>
> I am having random Linux Kernel crash problems while running FreeSWITCH as
> Skype to/from SIP gateway on one of our production servers. This machine is
> running CentOS 5.2, Kernel version 2.6.18-92.1.22.el5.centos.plusPAE with FS
> svn revision number 13754.
>
> At time of Kernel crash i could find following crash messages which point to
> some source code file in FS source tree.
>
>  --------------------- Kernel Begin ------------------------
>
>
>  3 Time(s):  =======================
>  3 Time(s):  [<c0404eff>] syscall_call+0x7/0xb
>  3 Time(s):  [<c043ed22>] sys_delete_module+0x192/0x1b8
>  3 Time(s):  [<c0449011>] audit_syscall_entry+0x14b/0x17d
>  3 Time(s):  [<c049f4fe>] remove_proc_entry+0x139/0x18c
>  3 Time(s):  [<f8d96281>] alsa_sound_exit+0xa/0x30 [snd]
>  3 Time(s):  [<f8d96304>] snd_info_done+0x46/0x49 [snd]
>  3 Time(s): BUG: warning at fs/proc/generic.c:732/remove_proc_entry() (Not
> tainted)
>  1 Time(s): snd-malloc: Memory leak?  pages not freed = 1
>
>  ---------------------- Kernel End -------------------------
>
> While the problem seems to arise from ALSA kernel module but it blames FS
> file fs/proc/generic.c:732 for this. The only FS module that is using ALSA
> is mod_skypiax but as far as i remember that module is using FS internal
> routines to allocate and de-allocate sound driver services for Skype client.
>
> Please suggest a solution.
>
> Thank you.
>
>
> --
> Muhammad Shahzad
> -----------------------------------
> CISCO Rich Media Communication Specialist (CRMCS)
> CISCO Certified Network Associate (CCNA)
> Cell: +92 334 422 40 88
> MSN: shari_786pk at hotmail.com
> Email: shaheryarkh at googlemail.com
>
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