Heikki Linnakangas 21cf4a3e11 Include # of bytes written in pgbench benchmark result ...

Now that the page server collects this metric (since commit 212920e47e),
let's include it in the performance test results

The new metric looks like this:

    performance/test_perf_pgbench.py .         [100%]
    --------------- Benchmark results ----------------
    test_pgbench.init: 6.784 s
    test_pgbench.pageserver_writes: 466 MB    <---- THIS IS NEW
    test_pgbench.5000_xacts: 8.196 s
    test_pgbench.size: 163 MB

    =============== 1 passed in 21.00s ===============

2021-09-07 15:12:39 +03:00

..

test_perf_pgbench.py

Include # of bytes written in pgbench benchmark result

2021-09-07 15:12:39 +03:00