Re: trace-cmd errors on kvm events

From: Jan Kiszka
Date: Fri Apr 08 2011 - 17:19:03 EST


On 2011-04-08 23:12, David Ahern wrote:
>
>
> On 04/08/11 15:07, Jan Kiszka wrote:
>> On 2011-04-08 20:53, David Ahern wrote:
>>> 2.6.38.2 kernel with trace-cmd git pulled this morning:
>>>
>>> trace-cmd record -e kvm
>>>
>>> trace-cmd report 2>&1 | less
>>>
>>> trace-cmd: No such file or directory
>>
>> Does this error come from trace-cmd failing to find its kvm plugin?
>> Check what strace -e open says.
>>
>> Jan
>>
>
> Tried that before - it was not enlightening.
> strace -e trace=open trace-cmd report 2>&1 | less
>
> open("/etc/ld.so.cache", O_RDONLY) = 3
> open("/lib64/libdl.so.2", O_RDONLY) = 3
> open("/lib64/libc.so.6", O_RDONLY) = 3
> open("/root/trace.dat", O_RDONLY) = 3
> trace-cmd: No such file or directory
> function ftrace_print_symbols_seq not defined
> failed to read event print fmt for kvm_nested_vmexit_inject
> function ftrace_print_symbols_seq not defined
> failed to read event print fmt for kvm_nested_vmexit
> function ftrace_print_symbols_seq not defined
> failed to read event print fmt for kvm_exit
> bad op token {
> failed to read event print fmt for kvm_emulate_insn
> open("/proc/meminfo", O_RDONLY) = 4

Let me check... indeed, I'm getting the same file-not-found here with
trace-cmd.git 9cce1c9b5b when starting it directly from its build directory.

But maybe your trace-cmd or kernel versions are too old / incompatible.
I'm not getting complaints about unparseable events with the above
snapshot and 2.6.38.

Jan

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