Revert "remove tracing, fix piggy, tune build"

This reverts commit f2517770c999d06abcbd1791cfd5080fcbd18024.
Revert "    Tune deadline, readahead, ondemand, interactive."

This reverts commit 0ff4c18e05a465fb01bbb1d5a1489506aaedcf84.
Revert "remove tracing, fix piggy, tune build"

This reverts commit b92e2d32f5806e1723b8dfb4f59af0acf21c7f07.