Bugzilla – Bug 460634
Unkillable process which needs 100%
Last modified: 2009-01-21 19:51:08 UTC
From time to time if I close kmail, kmail stays as a process (state: running) needing 100% of the CPU. You can't attach gdb or strace to the process. If you attach gdb with gdb to the process (gdb --args gdb --pid <pid>) then you can see that it hangs in a wait function for the pid. I run into the problem on my workstation (Core Duo) and at home with a single core AMD. The single core freezes completely. I've talked to Stefan at the party yesterday and he told me that he sometimes runs into the same problem with Thunderbird.
for reference to my issue see bug #458230
I had similar problems on my 64bit dualcore workstation with the following processes: -dovecot (imap) -kmail The problem seems to be related to the following kernel bug: http://lists-archives.org/linux-kernel/19774930-2-6-27-inotify-causes-unkillable-processes-with-100-cpu-usage.html Since i've updated my kernel to vanilla 2.6.27.10 i've never encountered that issue anymore.
I wasn't able to reproduce it today. So I can't provide a dump to verify it. I will try to reproduce it on my notebook in the next days.
Similar issue here, kernel hangs sometimes with dovecot running and thunderbird accessing it from a remote machine. Confer the thread starting with <http://www.dovecot.org/list/dovecot/2008-December/035662.html> on the dovecot mailing list. "strace -tt dovecot -F" on the broken machine gives the following output: [...] 16:32:41.634505 epoll_wait(9, {}, 21, 999) = 0 16:32:42.633796 gettimeofday({1230564762, 633972}, {0, 0}) = 0 16:32:42.634194 gettimeofday({1230564762, 634317}, NULL) = 0 16:32:42.634491 epoll_wait(9, {}, 21, 999) = 0 16:32:43.633809 gettimeofday({1230564763, 633987}, {0, 0}) = 0 16:32:43.634209 gettimeofday({1230564763, 634329}, NULL) = 0 16:32:43.634503 epoll_wait(9, The output suddenly stops there when the kernel crashes.
Kernel 2.6.28 plain vanilla runs fine here. Server has been running for 90 hours now without crash.
Since I'm running Kernel 2.6.27.10 the problem is gone.
thanks, am closing out.