From: Stefan Priebe Subject: Re: Asterisk deadlocks since Kernel 4.1 Date: Tue, 17 Nov 2015 20:27:25 +0100 Message-ID: <564B7F9D.5060701@profihost.ag> References: <564B3D35.50004@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Thomas Gleixner Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Am 17.11.2015 um 20:15 schrieb Thomas Gleixner: > On Tue, 17 Nov 2015, Stefan Priebe - Profihost AG wrote: >> since Upgrading our Asterisk System from Kernel 3.18.17 to 4.1.13 it >> deadlocks every few hours (kill -9 is the only thing working). Booting >> with 3.18 again let it run smooth again. >> >> An strace shows asterisk is looping like this: >> >> [pid 6068] timerfd_gettime(8, , {it_interval={0, 20000000}, >> it_value={0, 140592906050976}}) = 0 >> [pid 6068] read(8, "\1\0\0\0\0\0\0\0", 8) = 8 >> [pid 6068] poll([{fd=9, events=POLLIN}, {fd=8, events=POLLIN|POLLPRI}], >> 2, 1000) = 1 ([{fd=8, revents=POLLIN}]) >> [pid 6068] timerfd_gettime(8, , {it_interval={0, 20000000}, >> it_value={0, 140592906050976}}) = 0 >> [pid 6068] read(8, "\1\0\0\0\0\0\0\0", 8) = 8 >> >> fd 8 is: >> >> lrwx------ 1 root root 64 Nov 17 15:27 /proc/6025/fd/8 -> >> anon_inode:[timerfd] >> >> >> # cat /proc/6025/stack >> [] poll_schedule_timeout+0x49/0x70 >> [] do_sys_poll+0x3d7/0x590 >> [] do_restart_poll+0x3c/0x70 >> [] sys_restart_syscall+0x1f/0x30 >> [] system_call_fastpath+0x12/0x71 >> [] 0xffffffffffffffff >> >> Any ideas how to debug this? > > fd 8 is probably not really interesting. That looks like a interval > timer firing periodically. So it probably waits for fd 9 ... I've now also two gdb backtraces from two crashes: http://pastebin.com/raw.php?i=yih5jNt8 http://pastebin.com/raw.php?i=kGEcvH4T Stefan > > Thanks, > > tglx >