Deep I/O Performance Analysis of CernVM-FS using Modern Linux Tools

This report describes performance analysis of the CernVM-FS FUSE which is a software distribution 
service used in high-energy physics research. The performance analysis was conducted in both kernel 
space as well as in userland. One of the main tools used throughout the project implementation is BPF 
Compiler Collection (BCC). BCC was used for doing performance analysis on the kernel side of the 
FUSE calls in CernVM-FS. Some new tools were developed for retrieving performance statistics of the 
FUSE calls based on the guidelines for developing new BCC programs using the python interface. 
Besides the kernel space, FUSE userland calls were also undergone performance analysis by means 
of the code instrumentation. Additionally, log2 histogram was merged to the devel branch of the 
CernVM-FS code repository.