fork and USB3 performance drop in 10.1-BETA2

[Jin Guojun]

Run some comparison test on 10.1-BETA2 and see some performance drop especially the FORK and USB 3 read.

Attached is a performance comparison page. Column 2 and 3 are using the same hardware (AMD A8-660KK + ASUS A88XM-A M/B) but running 8.4 amd64 and 10.1BETA2 (highlighted area) amd64 kernels.

Row 3 in highlighted area shows multi-thread performance is still excellent but rest rows show performance drop especially everything below the multi-threading test (SMP MT).

Very last row shows that USB3 reading performance dropped to 45-55% (writing is OK). This was tested with four different USB3 drives.

Above that row, it shows fork performance -- 4 processors only gain 199% (24.6s) throughput (supposed close to 390+%), and two processors gained about 50% more (37.06s) compare single core another line above (48.28s).

The single core performance is also drop compare to 8.4 kernel on left.

Has anyone seen similar performance issue? or 10.1 requires some different turning trick?

-Jin