Re: trace-cmd errors on kvm events
On Fri, Apr 08, 2011 at 11:07:23PM +0200, 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. > I need to spend some time and fix it. That "No such file or directory" is from the way trace-cmd does error handling. It checks if errno is set and if so, it prints out perror(). What usually happens is I do a stat() on a file which sets errno, and forget about it. Then if trace-cmd finds some internal error, it calls the warning() message, which then prints out the stale errno. -- Steve -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: trace-cmd errors on kvm events
On 04/08/11 17:42, Jan Kiszka wrote: > What I also did is updating trace-cmd git and then reinstalling the > latest plugins: make install_plugins prefix=$HOME. They then end up in > $HOME/.trace-cmd/plugins. Now I do not have a single error message > anymore, including that file not found. Indeed. That did the trick. I was just running out of the build directory -- without doing an install of any kind. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: trace-cmd errors on kvm events
On 2011-04-09 01:26, David Ahern wrote: > On 04/08/11 15:18, Jan Kiszka wrote: >> Let me check... indeed, I'm getting the same file-not-found here with >> trace-cmd.git 9cce1c9b5b when starting it directly from its build directory. >> >> But maybe your trace-cmd or kernel versions are too old / incompatible. >> I'm not getting complaints about unparseable events with the above >> snapshot and 2.6.38. > > 2.6.38.2 kernel, trace-cmd 3e8b5b8 which is March 18 (though git pull > done this morning). > > For grins I checked-out 9cce1c9b5b and same error: > trace-cmd record -e kvm -- sleep 1 > trace-cmd report 2>&1 | less > > You do have to put stderr onto stdout to see the messages I reported > earlier. Or look for [FAILED TO PARSE] on the kvm_exit and > kvm_emulate_insn lines. I did that. What I also did is updating trace-cmd git and then reinstalling the latest plugins: make install_plugins prefix=$HOME. They then end up in $HOME/.trace-cmd/plugins. Now I do not have a single error message anymore, including that file not found. Jan signature.asc Description: OpenPGP digital signature
Re: trace-cmd errors on kvm events
On 04/08/11 15:18, Jan Kiszka wrote: > 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. 2.6.38.2 kernel, trace-cmd 3e8b5b8 which is March 18 (though git pull done this morning). For grins I checked-out 9cce1c9b5b and same error: trace-cmd record -e kvm -- sleep 1 trace-cmd report 2>&1 | less You do have to put stderr onto stdout to see the messages I reported earlier. Or look for [FAILED TO PARSE] on the kvm_exit and kvm_emulate_insn lines. David -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: trace-cmd errors on kvm events
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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Re: trace-cmd errors on kvm events
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
David
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Re: trace-cmd errors on kvm events
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 signature.asc Description: OpenPGP digital signature
Re: trace-cmd errors on kvm events
On 04/08/11 14:50, Stefan Hajnoczi wrote:
> On Fri, Apr 8, 2011 at 7:53 PM, 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
>> 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
>>
>>qemu-kvm-1864 [002] 2253.714134: kvm_entry:vcpu 1
>>qemu-kvm-1863 [008] 2253.714136: kvm_exit: [FAILED
>> TO PARSE] exit_reason=44 guest_rip=0xc01185ed isa=1 info1=4272 info2=0
>>qemu-kvm-1864 [002] 2253.714138: kvm_exit: [FAILED
>> TO PARSE] exit_reason=44 guest_rip=0xc01185ed isa=1 info1=4272 info2=0
>>qemu-kvm-1863 [008] 2253.714145: kvm_emulate_insn: [FAILED
>> TO PARSE] rip=3222373869 csbase=0 len=2 insn=<89>^H]<8B>^U<95>KU
>> <89>]<8D>^E flags=5 failed=0
>>
>> I have not used trace-cmd much, so I am not familiar with the code. Is
>> this a known issue? Suggestions on how to debug?
>
> I think there have been issues for a long time. I've never gotten
> perf or trace-cmd to be happy with kvm:* events. Here is a related
> thread from a while back:
>
> https://lkml.org/lkml/2010/5/26/194
>
> When I looked a while back the problem was due to how there is some
> preprocessor magic in Linux that ends up exporting C expressions as
> strings to userspace and neither perf nor trace-cmd have the parsing
> smarts to evaluate the C expressions at runtime.
Hmm.. ok. I thought it had been added - to trace-cmd at least. And I
recall Avi recently sending a patch to trace-cmd folks - I took that to
mean it works. Evidently, not.
David
>
> I ended up using ftrace instead which handles everything inside the
> kernel and compiles in those C expressions.
>
> Stefan
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Re: trace-cmd errors on kvm events
On Fri, Apr 8, 2011 at 7:53 PM, 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
> 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
>
> qemu-kvm-1864 [002] 2253.714134: kvm_entry: vcpu 1
> qemu-kvm-1863 [008] 2253.714136: kvm_exit: [FAILED
> TO PARSE] exit_reason=44 guest_rip=0xc01185ed isa=1 info1=4272 info2=0
> qemu-kvm-1864 [002] 2253.714138: kvm_exit: [FAILED
> TO PARSE] exit_reason=44 guest_rip=0xc01185ed isa=1 info1=4272 info2=0
> qemu-kvm-1863 [008] 2253.714145: kvm_emulate_insn: [FAILED
> TO PARSE] rip=3222373869 csbase=0 len=2 insn=<89>^H]<8B>^U<95>KU
> <89>]<8D>^E flags=5 failed=0
>
> I have not used trace-cmd much, so I am not familiar with the code. Is
> this a known issue? Suggestions on how to debug?
I think there have been issues for a long time. I've never gotten
perf or trace-cmd to be happy with kvm:* events. Here is a related
thread from a while back:
https://lkml.org/lkml/2010/5/26/194
When I looked a while back the problem was due to how there is some
preprocessor magic in Linux that ends up exporting C expressions as
strings to userspace and neither perf nor trace-cmd have the parsing
smarts to evaluate the C expressions at runtime.
I ended up using ftrace instead which handles everything inside the
kernel and compiles in those C expressions.
Stefan
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trace-cmd errors on kvm events
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
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
qemu-kvm-1864 [002] 2253.714134: kvm_entry:vcpu 1
qemu-kvm-1863 [008] 2253.714136: kvm_exit: [FAILED
TO PARSE] exit_reason=44 guest_rip=0xc01185ed isa=1 info1=4272 info2=0
qemu-kvm-1864 [002] 2253.714138: kvm_exit: [FAILED
TO PARSE] exit_reason=44 guest_rip=0xc01185ed isa=1 info1=4272 info2=0
qemu-kvm-1863 [008] 2253.714145: kvm_emulate_insn: [FAILED
TO PARSE] rip=3222373869 csbase=0 len=2 insn=<89>^H]<8B>^U<95>KU
<89>]<8D>^E flags=5 failed=0
I have not used trace-cmd much, so I am not familiar with the code. Is
this a known issue? Suggestions on how to debug?
Thanks,
David
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