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 21 | 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
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 21 | 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]C38B^UEC95KC0U 89E5]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 -- 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 Fri, Apr 8, 2011 at 7:53 PM, David Ahern dsah...@gmail.com wrote: 2.6.38.2 kernel with trace-cmd git pulled this morning: trace-cmd record -e kvm trace-cmd report 21 | 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]C38B^UEC95KC0U 89E5]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 -- 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 14:50, Stefan Hajnoczi wrote: On Fri, Apr 8, 2011 at 7:53 PM, David Ahern dsah...@gmail.com wrote: 2.6.38.2 kernel with trace-cmd git pulled this morning: trace-cmd record -e kvm trace-cmd report 21 | 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]C38B^UEC95KC0U 89E5]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 -- 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 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 21 | 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 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 21 | 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 21 | 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 -- 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 21 | 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 21 | 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 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 21 | 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 2011-04-09 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 21 | 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 $HOME/.trace-cmd/plugins. Now I do not have a single error message anymore, including that file not found. Jan signature.asc Description: OpenPGP digital signature
Re: trace-cmd errors on kvm events
On 04/08/11 17:42, Jan Kiszka wrote: What I also did is updating trace-cmd git and then reinstalling the latest plugins: make install_plugins prefix=$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