[MITgcm-devel] advection routines: strange results in flow trace analysis

Martin Losch Martin.Losch at awi.de
Wed Apr 9 10:29:44 EDT 2008


Hi there,

I have an unexpected result in flow trace analysis (see below). I am  
running the high resultion cubed sphere configuration (CS510) with 16  
passive tracers on 24CPU of a SX8-R, my advection scheme is 7 (os7mp)  
for the tracers and 33 (dst3fl) for the seaice variables. As expected  
the advection routines use most of the time (18 tracers). The flow  
trace analysis below gives the cumulative/average values in the first  
line, and then the values for the individual process in the following  
24 lines. However, if you look closely, you'll see that on some (8)  
cpus  the advection routine is called twice as often as on the  
remaining 16 cpus, this is true both for gad_os7mp_adv_x/y (which is  
called from gad_advection in this case) and gad_dst3fl_adv_x/y (which  
is called from seaice_advection in this case, not shown). We (Jens- 
Olaf and I) suspect that this imbalance is responsible for the  
terrible performance of the exch2-routines in this run that Chris and  
I talked about in February, because 16 cpus have to wait for 8 all  
the time in the exchange routines.

All other routines seem to be called with the same frequency on all  
CPUs.

What is the explanation for this?

Martin



> *--------------------------*
>   FLOW TRACE ANALYSIS LIST
> *--------------------------*
>
> Execution : Wed Apr  9 10:54:36 2008
> Total CPU : 13:40'31"663
>
>
> FREQUENCY  EXCLUSIVE       AVER.TIME    MOPS  MFLOPS V.OP  AVER.    
> VECTOR I-CACHE O-CACHE    BANK  PROG.UNIT
>            TIME[sec](  % )    [msec]                 RATIO V.LEN     
> TIME   MISS    MISS      CONF
>
>   6220800  6776.032( 13.8)     1.089 25809.1  7541.0 99.88 256.0  
> 6774.327  0.1500  0.1642 10.0670  gad_os7mp_adv_x
>    194400   211.705            1.089 25814.8  7542.6 99.88 256.0   
> 211.646  0.0084  0.0104  0.2688   0.0
>    194400   211.692            1.089 25816.3  7543.1 99.88 256.0   
> 211.641  0.0013  0.0027  0.2656   0.1
>    194400   211.890            1.090 25792.1  7536.0 99.88 256.0   
> 211.838  0.0014  0.0021  0.4195   0.10
>    194400   211.907            1.090 25790.2  7535.4 99.88 256.0   
> 211.852  0.0020  0.0024  0.4203   0.11
>    194400   211.706            1.089 25814.6  7542.5 99.88 256.0   
> 211.648  0.0059  0.0064  0.2785   0.12
>    194400   211.698            1.089 25815.6  7542.8 99.88 256.0   
> 211.644  0.0011  0.0019  0.2743   0.13
>    194400   211.720            1.089 25812.8  7542.0 99.88 256.0   
> 211.654  0.0171  0.0173  0.2838   0.14
>    194400   211.713            1.089 25813.8  7542.3 99.88 256.0   
> 211.658  0.0034  0.0041  0.2903   0.15
>    194400   211.673            1.089 25818.7  7543.8 99.88 256.0   
> 211.615  0.0096  0.0076  0.2493   0.16
>    194400   211.681            1.089 25817.7  7543.5 99.88 256.0   
> 211.613  0.0181  0.0169  0.2498   0.17
>    194400   211.645            1.089 25822.0  7544.7 99.88 256.0   
> 211.590  0.0041  0.0044  0.2292   0.18
>    194400   211.650            1.089 25821.4  7544.6 99.88 256.0   
> 211.596  0.0042  0.0045  0.2281   0.19
>    194400   211.684            1.089 25817.3  7543.4 99.88 256.0   
> 211.628  0.0050  0.0063  0.2656   0.2
>    388800   423.306            1.089 25821.1  7544.4 99.88 256.0   
> 423.206  0.0061  0.0076  0.4798   0.20
>    388800   423.311            1.089 25820.8  7544.4 99.88 256.0   
> 423.208  0.0057  0.0064  0.4736   0.21
>    388800   423.306            1.089 25821.1  7544.4 99.88 256.0   
> 423.204  0.0024  0.0031  0.4841   0.22
>    388800   423.321            1.089 25820.2  7544.2 99.88 256.0   
> 423.218  0.0017  0.0024  0.4834   0.23
>    194400   211.678            1.089 25818.0  7543.5 99.88 256.0   
> 211.625  0.0101  0.0112  0.2526   0.3
>    388800   423.756            1.090 25793.7  7536.4 99.88 256.0   
> 423.648  0.0025  0.0048  0.8570   0.4
>    388800   423.705            1.090 25796.7  7537.3 99.88 256.0   
> 423.595  0.0079  0.0095  0.8142   0.5
>    388800   423.733            1.090 25795.1  7536.8 99.88 256.0   
> 423.660  0.0159  0.0174  0.8413   0.6
>    388800   423.742            1.090 25794.5  7536.7 99.88 256.0   
> 423.647  0.0024  0.0039  0.8203   0.7
>    194400   211.906            1.090 25790.2  7535.4 99.88 256.0   
> 211.845  0.0124  0.0089  0.4195   0.8
>    194400   211.904            1.090 25790.4  7535.5 99.88 256.0   
> 211.849  0.0012  0.0019  0.4183   0.9
>   6220800  6482.742( 13.2)     1.042 27041.7  7882.1 99.88 256.0  
> 6480.721  0.5066  0.1471  7.7018  gad_os7mp_adv_y
>    194400   202.452            1.041 27059.5  7887.3 99.88 256.0   
> 202.387  0.0137  0.0075  0.2022   0.0
>    194400   202.439            1.041 27061.3  7887.8 99.88 256.0   
> 202.380  0.0073  0.0014  0.1965   0.1
>    388800   405.687            1.043 27007.3  7872.1 99.88 256.0   
> 405.582  0.0103  0.0025  0.6622   0.10
>    388800   405.711            1.043 27005.7  7871.6 99.88 256.0   
> 405.568  0.0446  0.0029  0.6483   0.11
>    194400   202.487            1.042 27054.9  7886.0 99.88 256.0   
> 202.422  0.0128  0.0065  0.2192   0.12
>    194400   202.461            1.041 27058.3  7887.0 99.88 256.0   
> 202.401  0.0084  0.0013  0.2061   0.13
>    194400   202.497            1.042 27053.5  7885.6 99.88 256.0   
> 202.425  0.0237  0.0147  0.2160   0.14
>    194400   202.519            1.042 27050.6  7884.7 99.88 256.0   
> 202.423  0.0424  0.0033  0.2155   0.15
>    388800   404.770            1.041 27068.5  7889.9 99.88 256.0   
> 404.664  0.0198  0.0146  0.3562   0.16
>    388800   404.766            1.041 27068.7  7890.0 99.88 256.0   
> 404.653  0.0310  0.0243  0.3585   0.17
>    388800   404.796            1.041 27066.7  7889.4 99.88 256.0   
> 404.692  0.0125  0.0057  0.3540   0.18
>    388800   404.830            1.041 27064.4  7888.8 99.88 256.0   
> 404.696  0.0435  0.0060  0.3553   0.19
>    194400   202.459            1.041 27058.6  7887.1 99.88 256.0   
> 202.396  0.0111  0.0046  0.1934   0.2
>    194400   202.395            1.041 27067.1  7889.5 99.88 256.0   
> 202.338  0.0094  0.0032  0.1811   0.20
>    194400   202.400            1.041 27066.4  7889.3 99.88 256.0   
> 202.342  0.0092  0.0030  0.1827   0.21
>    194400   202.406            1.041 27065.6  7889.1 99.88 256.0   
> 202.347  0.0074  0.0012  0.1768   0.22
>    194400   202.438            1.041 27061.4  7887.9 99.88 256.0   
> 202.347  0.0376  0.0008  0.1773   0.23
>    194400   202.473            1.042 27056.8  7886.5 99.88 256.0   
> 202.392  0.0463  0.0091  0.1846   0.3
>    194400   202.854            1.043 27005.8  7871.7 99.88 256.0   
> 202.791  0.0090  0.0011  0.3488   0.4
>    194400   202.871            1.044 27003.6  7871.0 99.88 256.0   
> 202.806  0.0125  0.0041  0.3407   0.5
>    194400   202.796            1.043 27013.6  7873.9 99.88 256.0   
> 202.748  0.0174  0.0081  0.3077   0.6
>    194400   202.880            1.044 27002.5  7870.7 99.88 256.0   
> 202.788  0.0424  0.0012  0.3204   0.7
>    388800   405.695            1.043 27006.7  7871.9 99.88 256.0   
> 405.581  0.0246  0.0181  0.6572   0.8
>    388800   405.660            1.043 27009.1  7872.6 99.88 256.0   
> 405.551  0.0097  0.0021  0.6412   0.9
>   4572288  5253.314( 10.7)     1.149 26038.1  7946.7 99.88 255.2  
> 5251.591  0.1115  0.1259  8.4362  gad_os7mp_adv_r
>    190512   218.247            1.146 26114.6  7970.0 99.88 255.2   
> 218.173  0.0070  0.0075  0.2710   0.0
>    190512   218.203            1.145 26119.9  7971.6 99.88 255.2   
> 218.134  0.0012  0.0023  0.2445   0.1
>    190512   219.379            1.152 25979.8  7928.9 99.88 255.2   
> 219.309  0.0017  0.0023  0.4233   0.10
>    190512   219.377            1.152 25980.0  7929.0 99.88 255.2   
> 219.305  0.0019  0.0021  0.4169   0.11
>    190512   218.427            1.147 26093.0  7963.4 99.88 255.2   
> 218.354  0.0051  0.0057  0.2925   0.12
>    190512   218.376            1.146 26099.1  7965.3 99.88 255.2   
> 218.305  0.0010  0.0017  0.2655   0.13
>    190512   218.430            1.147 26092.7  7963.4 99.88 255.2   
> 218.352  0.0144  0.0143  0.2949   0.14
>    190512   218.424            1.147 26093.4  7963.6 99.88 255.2   
> 218.353  0.0029  0.0035  0.2948   0.15
>    190512   218.846            1.149 26043.1  7948.2 99.88 255.2   
> 218.771  0.0073  0.0077  0.3413   0.16
>    190512   218.903            1.149 26036.3  7946.1 99.88 255.2   
> 218.826  0.0131  0.0131  0.3785   0.17
>    190512   218.789            1.148 26049.9  7950.3 99.88 255.2   
> 218.716  0.0035  0.0039  0.3222   0.18
>    190512   218.737            1.148 26056.1  7952.2 99.88 255.2   
> 218.665  0.0036  0.0037  0.3009   0.19
>    190512   218.213            1.145 26118.6  7971.3 99.88 255.2   
> 218.141  0.0043  0.0052  0.2531   0.2
>    190512   219.118            1.150 26010.8  7938.3 99.88 255.2   
> 219.046  0.0034  0.0044  0.3932   0.20
>    190512   219.104            1.150 26012.3  7938.8 99.88 255.2   
> 219.032  0.0031  0.0039  0.3778   0.21
>    190512   219.107            1.150 26012.0  7938.7 99.88 255.2   
> 219.034  0.0018  0.0023  0.3809   0.22
>    190512   219.113            1.150 26011.3  7938.5 99.88 255.2   
> 219.040  0.0011  0.0014  0.3814   0.23
>    190512   218.109            1.145 26131.1  7975.1 99.88 255.2   
> 218.042  0.0086  0.0092  0.2149   0.3
>    190512   219.504            1.152 25965.0  7924.4 99.88 255.2   
> 219.429  0.0017  0.0031  0.4977   0.4
>    190512   219.464            1.152 25969.7  7925.8 99.88 255.2   
> 219.390  0.0043  0.0052  0.4517   0.5
>    190512   219.381            1.152 25979.6  7928.8 99.88 255.2   
> 219.328  0.0083  0.0088  0.4260   0.6
>    190512   219.394            1.152 25978.0  7928.4 99.88 255.2   
> 219.327  0.0017  0.0027  0.4132   0.7
>    190512   219.319            1.151 25987.0  7931.1 99.88 255.2   
> 219.243  0.0091  0.0097  0.3975   0.8
>    190512   219.351            1.151 25983.1  7929.9 99.88 255.2   
> 219.277  0.0013  0.0022  0.4027   0.9
>



More information about the MITgcm-devel mailing list