Python 3.15's Ultra-Low Overhead Interpreter Profiling Mode – Ken Jin's Blog

3 comments

• NeutralForest 36 minutes ago
  Here are explanation on how to use it from one of the people working on it: https://www.youtube.com/watch?v=f1x4X83CDSA and the chunky docs that go with it in the beta of 3.15: https://docs.python.org/3.15/library/profiling.sampling.html
• evomassiny 2 hours ago
  Could you duplicate `RECORD_INST` before each `INSTRUCTION_N`, so that:

  ```

     INSTRUCTION_1:
       // subroutine 1
       ip++;
       goto *dispatch_var[*ip];
  
     INSTRUCTION_2:
       // subroutine 2
       ip++;
       goto *dispatch_var[*ip];
  

  ```

  becomes: ```

     RECORD_INST_1:
       // record logic
     INSTRUCTION_1:
       // subroutine 1
       ip++;
       goto *dispatch_var[*ip];
  
     RECORD_INST_2:
       // record logic
     INSTRUCTION_2:
       // subroutine 2
       ip++;
       goto *dispatch_var[*ip];

  ```

  This way you could directly swap `dispatch_var` with an array populated with the `RECORD_INST_*` labels, and remove one step at runtime.

  Or maybe this is what you are trying to avoid to reduce the binary size ?

  [-]
  • kzrdude 2 hours ago
    That sounds smart, maybe worth testing, but I think it bloats the instruction cache even when not tracing.
• haeseong 2 hours ago
  [dead]