c2clat

A tool to measure CPU core to core latency (inter-core latency).

Build:

g++ -O3 -DNDEBUG c2clat.cpp -o c2clat -pthread

Example usage:

$ ./c2clat 
 CPU    0    1    2    3    4    5    6    7
   0    0   92   66   62   16   56   54   53
   1   92    0   50   54   53   14   49   50
   2   66   50    0   48   51   49   13   48
   3   62   54   48    0   53   50   48   13
   4   16   53   51   53    0   53   51   53
   5   56   14   49   50   53    0   49   50
   6   54   49   13   48   51   49    0   48
   7   53   50   48   13   53   50   48    0

Create plot using gnuplot:

c2clat -p | gnuplot -p

If you want to run on a subset of cores use taskset:

$ taskset -c 10-11 ./c2clat
 CPU   10   11
  10    0   52
  11   52    0

If you want to label the heatmap plot replace the plot command with:

plot '$data' matrix rowheaders columnheaders using 2:1:3 with image, \
     '$data' matrix rowheaders columnheaders using 2:1:(sprintf("%g",$3)) with labels