Test machine: Intel Ivybridge (i7-3770K @ 4.50 GHz).
Software:
- Arch Linux x86_64.
- Official gcc and gcc-libs packages (4.8.1-3) used to both compile the kernel packages and to run the benchmarks.
- Kernel packages differ only in the ck1 patch used; all other config files held constant
- The config file is the stock Arch Linux config.x86_64 for the 3.11-1 package.
Results: BFS was superior to CFS on this machine; results true for both make endpoints.
Median speed gain for building bzImage with bfs v0.441: 1,452 ms
Median speed gain for building samba with bfs v0.441: 600 ms
Data/Analysis:
Results for bzImage
Results for samba
Note for those of you really paying attention:
Both benchmarks used `make -j9 ...` even though the 3770k is a quad (4
physical + 4 virtual=8). I am aware that it is recommended NOT to use
the x+1 formula for kernels running the BFS but felt that in order to
fairly compare both schedulers, this needed to be held constant. That
said, I have done some experiments where I varied the make flags (8, 9,
10) and found that there was no statistically significant difference on
the BFS.