Re: Benchmarking results: DSS elapsed time values w/ rq_affinity=0/1 - Jens' for-2.6.28 tree

["Alan D. Brunelle" <Alan.Brunelle@hp.com>]

Here are some results obtained during runs where we varied the number of
 readers & the multi-block read counts. 5 runs per rq_affinity setting
were done, and the averages are plotted at:

http://free.linux.hp.com/~adb/jens/08-09-05/by_mbr.jpeg

In all cases we are seeing a noticeable improvement in reduction of
elapsed time to perform the tasks, and again we are seeing much tighter
deviations with rq_affinity set to 1:

                          Min   Avg   Max   Std Dev
                         ----- ----- -----  --------
mbrs= 32 nrdrs= 64 rq=0: 30.57 31.50 34.06  1.456108
mbrs= 32 nrdrs= 64 rq=1: 29.27 29.59 29.96  0.325469   6.05% improvement

mbrs= 32 nrdrs=128 rq=0: 28.14 28.48 29.32  0.480208
mbrs= 32 nrdrs=128 rq=1: 27.54 27.88 28.48  0.359194   2.11% improvement

mbrs= 32 nrdrs=256 rq=0: 33.05 33.70 34.30  0.548151
mbrs= 32 nrdrs=256 rq=1: 33.10 33.36 33.74  0.257158   1.01% improvement

mbrs= 64 nrdrs= 64 rq=0: 30.53 30.74 31.10  0.255441
mbrs= 64 nrdrs= 64 rq=1: 29.40 29.65 29.91  0.187216   3.55% improvement

mbrs= 64 nrdrs=128 rq=0: 28.09 28.79 29.23  0.484149
mbrs= 64 nrdrs=128 rq=1: 27.73 27.96 28.33  0.226429   2.89% improvement

mbrs= 64 nrdrs=256 rq=0: 33.35 34.04 34.76  0.518816
mbrs= 64 nrdrs=256 rq=1: 33.02 33.13 33.25  0.088034   2.67% improvement

mbrs=128 nrdrs= 64 rq=0: 30.37 30.75 31.23  0.329439
mbrs=128 nrdrs= 64 rq=1: 29.20 29.49 29.82  0.221179   4.08% improvement

mbrs=128 nrdrs=128 rq=0: 28.04 28.54 29.00  0.392785
mbrs=128 nrdrs=128 rq=1: 27.76 28.08 28.26  0.190840   1.63% improvement

mbrs=128 nrdrs=256 rq=0: 33.37 33.89 34.30  0.448297
mbrs=128 nrdrs=256 rq=1: 33.04 33.30 33.56  0.203175   1.76% improvement

mbrs=256 nrdrs= 64 rq=0: 30.55 30.80 30.94  0.167392
mbrs=256 nrdrs= 64 rq=1: 29.23 29.57 29.91  0.305156   3.99% improvement

mbrs=256 nrdrs=128 rq=0: 28.38 28.82 29.20  0.305172
mbrs=256 nrdrs=128 rq=1: 27.78 27.92 28.11  0.142583   3.12% improvement

mbrs=256 nrdrs=256 rq=0: 33.25 34.21 34.88  0.598398
mbrs=256 nrdrs=256 rq=1: 33.11 33.23 33.48  0.154499   2.88% improvement