sendfile: fd=3 s=4 header=56 MB ...
sendfile returned rc=-1 errno=22 (Invalid argument) sbytes=1
=== SAMPLES ===
   1 256/33296 mbuf clusters in use (current/max)
   1 26684/33296 mbuf clusters in use (current/max)
=== PEAK ===
26684/33296 mbuf clusters in use (current/max)