Stefan Sperling stsp@bsd.network

To get a rough idea about the impact of WPA2 crypto hardware offloading, tobhe@ has generated two flamegraphs with the new dt(4) dynamic tracer written by mpi@.

These graphs plot a "profile:hz:11" bt(5) probe before and after the above patch.

Before: https://tobhe.de/files/wifi.svg

After: https://tobhe.de/files/wifi-new.svg

It looks like iwm_tx() disappears in the second graph. Its overhead is reduced such that it never showed up whenever the profiler took its periodic kernel stack snapshot :flan_ooh:​