hstress: nprocs > 1 seems unreliable

[evan]

When run locally, I get one reporting line and then hstress halts and reports the summary.

$ ./hstress -c 93 -b 1,5,10,50,100,500,1000 -p 3 -r 0 -i 1 scala-finagle.herokuapp.com 80 
# params: -c 93 -n -1 -p 3 -r 0 -i 1 -l 0 -u / scala-finagle.herokuapp.com 80
#       conn    conn    conn    conn    http    http
# ts        success errors  timeout closes  success error   <1  <5  <10 <50 <100    <500    <1000   >=1000  hz 
1332096314  235 0   44  279 235 0   0   0   0   0   0   229 6   0   167
# conn_successes    235 0.84229
...