Re: [gentoo-user] unstoppable, undeciperable kernel call trace in log
On Sat, Jun 30, 2012 at 4:57 PM, Maxim Wexler maxim.wex...@gmail.com wrote: Hi group, Please take a look at this clip from /var/log/messages: https://paste.lugons.org/show/2679/ Can somebody tell me what it means? It never changes, char by char. It goes on forever, over and over again. At one time I wanted kernel debugging, but I've returned to menuconfig and turned it off(I thought ). How do I stop this pointless verbosity? Hi, I don't have an answer, but if you google the phrase rcu_bh detected stall on CPU you can find many reports similar to yours and maybe some information. Do you have RCU_CPU_STALL_INFO=y in your kernel config?
Re: [gentoo-user] unstoppable, undeciperable kernel call trace in log
Hi, I don't have an answer, but if you google the phrase rcu_bh detected stall on CPU you can find many reports similar to yours and maybe some information. This might be usefu lhttp://www.kernel.org/doc/Documentation/RCU/stallwarn.txt RCU bugs can often be debugged with the help of CONFIG_RCU_TRACE from help in menuconfig. │ This option provides tracing in RCU which presents stats│ │ in debugfs for debugging RCU implementation. Ok, so I've set the RCU_TRACE=y. Next question: How do I use debugfs, never used it before? Do you have RCU_CPU_STALL_INFO=y in your kernel config? no. syzygy@lumby ~ $ grep RCU /usr/src/linux/.config # RCU Subsystem CONFIG_TREE_RCU=y # CONFIG_PREEMPT_RCU is not set # CONFIG_RCU_TRACE is not set CONFIG_RCU_FANOUT=32 # CONFIG_RCU_FANOUT_EXACT is not set # CONFIG_RCU_FAST_NO_HZ is not set # CONFIG_TREE_RCU_TRACE is not set # CONFIG_SPARSE_RCU_POINTER is not set CONFIG_RCU_CPU_STALL_TIMEOUT=60
Re: [gentoo-user] unstoppable, undeciperable kernel call trace in log
This is weird syzygy@lumby ~ $ grep DEBUG_FS /usr/src/linux/.config # CONFIG_DEBUG_FS is not set But the entry in menuconfig -kernel hacking looks like this:' -*- Debug Filesystem', and can't be changed. Not '[*]' which is changeable with the spacebar, but '-*-' which is not. According to help it depends on TREE_RCU_TRACE=y OR a whole bunch of other stuff. But I have TREE_RCU_TRACE=y. So I should be good right? But then why doesn't it select DEBUG_FS? googling lead me to http://en.wikipedia.org/wiki/Debugfs, which says do: 'mount -t debugfs none /sys/kernel/debug'. Ok, but there's no debug file or dir under /sys/kernel. Do I make one? And will it make a difference since according to grep DEBUG_FS is not set in the kernel config? I'll go and make the new kernel and see what happens. On 6/30/12, Maxim Wexler maxim.wex...@gmail.com wrote: Hi, I don't have an answer, but if you google the phrase rcu_bh detected stall on CPU you can find many reports similar to yours and maybe some information. This might be usefu lhttp://www.kernel.org/doc/Documentation/RCU/stallwarn.txt RCU bugs can often be debugged with the help of CONFIG_RCU_TRACE from help in menuconfig. │ This option provides tracing in RCU which presents stats │ │ in debugfs for debugging RCU implementation. Ok, so I've set the RCU_TRACE=y. Next question: How do I use debugfs, never used it before? Do you have RCU_CPU_STALL_INFO=y in your kernel config? no. syzygy@lumby ~ $ grep RCU /usr/src/linux/.config # RCU Subsystem CONFIG_TREE_RCU=y # CONFIG_PREEMPT_RCU is not set # CONFIG_RCU_TRACE is not set CONFIG_RCU_FANOUT=32 # CONFIG_RCU_FANOUT_EXACT is not set # CONFIG_RCU_FAST_NO_HZ is not set # CONFIG_TREE_RCU_TRACE is not set # CONFIG_SPARSE_RCU_POINTER is not set CONFIG_RCU_CPU_STALL_TIMEOUT=60
