a perf tool which accesses the performance counter registers of an machine and gives out metrcis to user to analyse the system performance

what i am curious about is  , when i read the parts of code. i see perf reading something from a mmemory mapped area(i feel it reads an area which is been written by kernel),it is also reading /proc/modules, but i could not find any code related to actual read of hardware registers of machine, how actually perf records its samples ? how does it identify what function is an executable is executing ? and how does it know the symbols ?

does kernel also has a module of perf inside ? apart from /tools to convey the application 'perf' running in user space

can any one brief me about the internal working in detail

perf is a tool which accesses the performance counter registers of an machine and gives out metrics to user to analyze the system performance.

What I am curious about is, when I read the parts of code. I see perf reading something from a memory mapped area  (I feel it reads an area which is been written by the kernel), it is also reading /proc/modules, but I could not find any code related to actual read of hardware registers of machine.

• How does perf actually record its samples?
• How does it identify what function is an executable is executing?
• How does it know the symbols?

Does the kernel also have a module of perf inside (apart from /tools to convey the application 'perf' running in user space)?

Can anyone brief me about the internal working in detail?

a perf tool which accesses the performance counter registers of an machine and gives out metrcis to user to analyse the system performance

what i am curious about is when i read the parts of code i see perf reading something from a mmemory mapped area(i feel it reads an area which is been written by kernel), how actually perf records its samples, how does it identify what function is an executable is executing and how does it know the symbols

can any one brief me about the internal working detailed

a perf tool which accesses the performance counter registers of an machine and gives out metrcis to user to analyse the system performance

what i am curious about is , when i read the parts of code. i see perf reading something from a mmemory mapped area(i feel it reads an area which is been written by kernel),it is also reading /proc/modules, but i could not find any code related to actual read of hardware registers of machine, how actually perf records its samples ? how does it identify what function is an executable is executing ? and how does it know the symbols ?

does kernel also has a module of perf inside ? apart from /tools to convey the application 'perf' running in user space

can any one brief me about the internal working in detail