aaupov
commented
2 years ago Hi @ptr1337,
Thank you for your interest in this project and insightful straight to the point questions.
Please note that this is a high school project implemented by Maksim @M4RFF. It's not ready for general use yet, so think of it as a prototype.
Actually every built binary need be built with --emit-relocs , so that bolt works. So, the distribution should all compile the packages with that, or do you have another solution for that ?
It's true that to get the most benefit, the object file would need to be linked with relocations. But 1) BOLT works in non-relocation mode as well, 2) perfd may detect a lack of relocs and either warn about it or deprioritize the application.
Changing the language from russian to english so that every user understand it would be also nice.
It would be addressed soon. I'll help Maksim with it but let him add documentation in Russian first.
How about cpu's which does not support perf record (eg amd ones)? Do you plan to implement the feature -instrument and then bolt the binary after enough data is made ?
It's a valid concern. You're right, perfd would need to detect the presence of LBR and perhaps use non-LBR sampling otherwise (frame ptr stack unwinding, as DWARF is unlikely to be available either). The instrumentation mode might be added as an extension too.
ptr1337
Hey,
first great idea this project, really looking forward.
The questions I got:
Actually every built binary need be built with
--emit-relocs, so that bolt works. So, the distribution should all compile the packages with that, or do you have another solution for that ?Changing the language from russian to english so that every user understand it would be also nice.
How about cpu's which does not support perf record (eg amd ones)? Do you plan to implement the feature -instrument and then bolt the binary after enough data is made ?
Regards.