the performance of IO manager in GHC 7.10.1rc2

[Kazu Yamamoto (=?iso-2022-jp?B?GyRCOzNLXE9CSScbKEI=?=)]

Hi,

As usual, I took benchmark of IO manager to check if preformance
regression is introduced. Fortunately, I don't see any preformance
regression.

+RTS -N<x>    1        2        4        8        16
---------------------------------------------------------
GHC7.8.4       81,413  153,478  270,178  406,448  50,3203
GHC7.10.1rc2   88,247  148,471  265,392  409,514  49,3890

Environment: two real 20 cores machines directly connected by 20G
  - Xeon E5-2650Lv2 (1.70GHz/10cores/25MB) x 2, 8GM, no HT
  - CentOS 7.0
  - Two 10Gs are aggregated

Server: witty -a -m -r 8080 +RTS -A32m -N<x>

Benchmark: weighttp -n 100000 -c 1000 -k -t 16 http://<ip-addr>/

P.S.

If Ben's patch will be included in GHC 7.10, I will try this again.

--Kazu