Error: kernel NOT compiled with frame pointers

Error: kernel NOT compiled with frame pointers

imagem de Tao Yang (Intel)

ÖS : SUSE SLES 11 SP2 x86_64
Hardware : E5-2600 DP system
Intel(R) VTune(TM) Amplifier XE 2013 Update 2"

It will print this error message. What is the side effect of it?

[   24.498884] **********************************************************************************************************
[   24.498890] Error: kernel NOT compiled with frame pointers -- NO KERNEL-SPACE TIMER CALL TRACES WILL BE GENERATED!
[   24.498893] **********************************************************************************************************

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Para obter mais informações sobre otimizações de compiladores, consulte Aviso sobre otimizações.
imagem de Peter Wang (Intel)

This info only impacts on Linux kernel modules - usually you use VTune(TM) Amplifier XE to profile your program. As result, both your module(s) and system module(s) will be profiled (your program might call runtime libraries in system/kernel modules).

If your program was built with "-g" compiler option, all hot function names in your module(s) will be displayed with performance data, with call stack info. However if your system module was not built with CONFIG_DEBUG_INFO (which is called "Compile the kernel with debug info" in the config menu, while compiling Linux kernel modules), all hot functions in kernel modules will only be displayed as [vmlinux], and without stack info.
Read this article http://software.intel.com/en-us/articles/why-cant-functions-in-kernel-be... to know more info

CONFIG_FRAME_POINTER kernel option which is called "Compile the kernel with frame pointers" in the config menu. This option inserts code to into the compiled executable which saves the frame information in registers or on the stack at different points which allows a debugger such as gdb to more accurately construct stack back traces while debugging the kernel. So it only suffers on performance data of kernel modules, WITHOUT stakc info from VTune Amplifier XE result.

imagem de blackburried

Just to clarify, if profiling kernel modules in distributions like SLES11 where CONFIG_FRAME_POINTER=n, VTune won't generate reliable data?

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