[petsc-users] [External] Re: request to add an option similar to use_omp_threads for mumps to cusparse solver

Chang Liu cliu at pppl.gov
Thu Oct 14 21:11:57 CDT 2021


For comparison, here is the output using mumps instead of cusparse

$ mpiexec -n 16 --hostfile hostfile --oversubscribe ./ex7 -m 400 
-ksp_view -ksp_monitor_true_residual -pc_type bjacobi -pc_bjacobi_blocks 
4 -ksp_type fgmres -mat_type aijcusparse -sub_pc_type telescope 
-sub_ksp_type preonly -sub_telescope_ksp_type preonly 
-sub_telescope_pc_type lu -sub_telescope_pc_factor_mat_solver_type mumps 
-sub_pc_telescope_reduction_factor 4 -sub_pc_telescope_subcomm_type 
contiguous -ksp_max_it 2000 -ksp_rtol 1.e-20 -ksp_atol 1.e-9
   0 KSP unpreconditioned resid norm 4.014971979977e+01 true resid norm 
4.014971979977e+01 ||r(i)||/||b|| 1.000000000000e+00
   1 KSP unpreconditioned resid norm 2.439995191694e+00 true resid norm 
2.439995191694e+00 ||r(i)||/||b|| 6.077240896978e-02
   2 KSP unpreconditioned resid norm 1.280694102588e+00 true resid norm 
1.280694102588e+00 ||r(i)||/||b|| 3.189795866509e-02
   3 KSP unpreconditioned resid norm 1.041100266810e+00 true resid norm 
1.041100266810e+00 ||r(i)||/||b|| 2.593044912896e-02
   4 KSP unpreconditioned resid norm 7.274347137268e-01 true resid norm 
7.274347137268e-01 ||r(i)||/||b|| 1.811805206499e-02
   5 KSP unpreconditioned resid norm 5.429229329787e-01 true resid norm 
5.429229329787e-01 ||r(i)||/||b|| 1.352245882876e-02
   6 KSP unpreconditioned resid norm 4.332970410353e-01 true resid norm 
4.332970410353e-01 ||r(i)||/||b|| 1.079203150598e-02
   7 KSP unpreconditioned resid norm 3.948206050950e-01 true resid norm 
3.948206050950e-01 ||r(i)||/||b|| 9.833707609019e-03
   8 KSP unpreconditioned resid norm 3.379580577269e-01 true resid norm 
3.379580577269e-01 ||r(i)||/||b|| 8.417444988714e-03
   9 KSP unpreconditioned resid norm 2.875593971410e-01 true resid norm 
2.875593971410e-01 ||r(i)||/||b|| 7.162176936105e-03
  10 KSP unpreconditioned resid norm 2.533983363244e-01 true resid norm 
2.533983363244e-01 ||r(i)||/||b|| 6.311335112378e-03
  11 KSP unpreconditioned resid norm 2.389169921094e-01 true resid norm 
2.389169921094e-01 ||r(i)||/||b|| 5.950651543793e-03
  12 KSP unpreconditioned resid norm 2.118961639089e-01 true resid norm 
2.118961639089e-01 ||r(i)||/||b|| 5.277649880637e-03
  13 KSP unpreconditioned resid norm 1.885892030223e-01 true resid norm 
1.885892030223e-01 ||r(i)||/||b|| 4.697148671593e-03
  14 KSP unpreconditioned resid norm 1.763510666948e-01 true resid norm 
1.763510666948e-01 ||r(i)||/||b|| 4.392336175055e-03
  15 KSP unpreconditioned resid norm 1.638219366731e-01 true resid norm 
1.638219366731e-01 ||r(i)||/||b|| 4.080275964317e-03
  16 KSP unpreconditioned resid norm 1.476792766432e-01 true resid norm 
1.476792766432e-01 ||r(i)||/||b|| 3.678214378076e-03
  17 KSP unpreconditioned resid norm 1.349906937321e-01 true resid norm 
1.349906937321e-01 ||r(i)||/||b|| 3.362182710248e-03
  18 KSP unpreconditioned resid norm 1.289673236836e-01 true resid norm 
1.289673236836e-01 ||r(i)||/||b|| 3.212159993314e-03
  19 KSP unpreconditioned resid norm 1.167505658153e-01 true resid norm 
1.167505658153e-01 ||r(i)||/||b|| 2.907879965230e-03
  20 KSP unpreconditioned resid norm 1.046037988999e-01 true resid norm 
1.046037988999e-01 ||r(i)||/||b|| 2.605343185995e-03
  21 KSP unpreconditioned resid norm 9.832660514331e-02 true resid norm 
9.832660514331e-02 ||r(i)||/||b|| 2.448998539309e-03
  22 KSP unpreconditioned resid norm 8.835618950141e-02 true resid norm 
8.835618950142e-02 ||r(i)||/||b|| 2.200667649539e-03
  23 KSP unpreconditioned resid norm 7.563496650115e-02 true resid norm 
7.563496650116e-02 ||r(i)||/||b|| 1.883823022386e-03
  24 KSP unpreconditioned resid norm 6.651291376834e-02 true resid norm 
6.651291376834e-02 ||r(i)||/||b|| 1.656622115921e-03
  25 KSP unpreconditioned resid norm 5.890393227906e-02 true resid norm 
5.890393227906e-02 ||r(i)||/||b|| 1.467106933070e-03
  26 KSP unpreconditioned resid norm 4.661992782780e-02 true resid norm 
4.661992782780e-02 ||r(i)||/||b|| 1.161152009536e-03
  27 KSP unpreconditioned resid norm 3.690705358716e-02 true resid norm 
3.690705358716e-02 ||r(i)||/||b|| 9.192356452602e-04
  28 KSP unpreconditioned resid norm 3.209680460188e-02 true resid norm 
3.209680460188e-02 ||r(i)||/||b|| 7.994278605666e-04
  29 KSP unpreconditioned resid norm 2.354337626000e-02 true resid norm 
2.354337626001e-02 ||r(i)||/||b|| 5.863895533373e-04
  30 KSP unpreconditioned resid norm 1.701296561785e-02 true resid norm 
1.701296561785e-02 ||r(i)||/||b|| 4.237380908932e-04
  31 KSP unpreconditioned resid norm 1.509942937258e-02 true resid norm 
1.509942937258e-02 ||r(i)||/||b|| 3.760780759588e-04
  32 KSP unpreconditioned resid norm 1.258274688515e-02 true resid norm 
1.258274688515e-02 ||r(i)||/||b|| 3.133956338402e-04
  33 KSP unpreconditioned resid norm 9.805748771638e-03 true resid norm 
9.805748771638e-03 ||r(i)||/||b|| 2.442295692359e-04
  34 KSP unpreconditioned resid norm 8.596552678160e-03 true resid norm 
8.596552678160e-03 ||r(i)||/||b|| 2.141123953301e-04
  35 KSP unpreconditioned resid norm 6.936406707500e-03 true resid norm 
6.936406707500e-03 ||r(i)||/||b|| 1.727635147167e-04
  36 KSP unpreconditioned resid norm 5.533741607932e-03 true resid norm 
5.533741607932e-03 ||r(i)||/||b|| 1.378276519869e-04
  37 KSP unpreconditioned resid norm 4.982347757923e-03 true resid norm 
4.982347757923e-03 ||r(i)||/||b|| 1.240942099414e-04
  38 KSP unpreconditioned resid norm 4.309608348059e-03 true resid norm 
4.309608348059e-03 ||r(i)||/||b|| 1.073384414524e-04
  39 KSP unpreconditioned resid norm 3.729408303186e-03 true resid norm 
3.729408303185e-03 ||r(i)||/||b|| 9.288753001974e-05
  40 KSP unpreconditioned resid norm 3.490003351128e-03 true resid norm 
3.490003351128e-03 ||r(i)||/||b|| 8.692472496776e-05
  41 KSP unpreconditioned resid norm 3.069012426454e-03 true resid norm 
3.069012426453e-03 ||r(i)||/||b|| 7.643919912166e-05
  42 KSP unpreconditioned resid norm 2.772928845284e-03 true resid norm 
2.772928845284e-03 ||r(i)||/||b|| 6.906471225983e-05
  43 KSP unpreconditioned resid norm 2.561454192399e-03 true resid norm 
2.561454192398e-03 ||r(i)||/||b|| 6.379756085902e-05
  44 KSP unpreconditioned resid norm 2.253662762802e-03 true resid norm 
2.253662762802e-03 ||r(i)||/||b|| 5.613146926159e-05
  45 KSP unpreconditioned resid norm 2.086800523919e-03 true resid norm 
2.086800523919e-03 ||r(i)||/||b|| 5.197546917701e-05
  46 KSP unpreconditioned resid norm 1.926028182896e-03 true resid norm 
1.926028182896e-03 ||r(i)||/||b|| 4.797114880257e-05
  47 KSP unpreconditioned resid norm 1.769243808622e-03 true resid norm 
1.769243808622e-03 ||r(i)||/||b|| 4.406615581492e-05
  48 KSP unpreconditioned resid norm 1.656654905964e-03 true resid norm 
1.656654905964e-03 ||r(i)||/||b|| 4.126192945371e-05
  49 KSP unpreconditioned resid norm 1.572052627273e-03 true resid norm 
1.572052627273e-03 ||r(i)||/||b|| 3.915475961260e-05
  50 KSP unpreconditioned resid norm 1.454960682355e-03 true resid norm 
1.454960682355e-03 ||r(i)||/||b|| 3.623837699518e-05
  51 KSP unpreconditioned resid norm 1.375985053014e-03 true resid norm 
1.375985053014e-03 ||r(i)||/||b|| 3.427134883820e-05
  52 KSP unpreconditioned resid norm 1.269325501087e-03 true resid norm 
1.269325501087e-03 ||r(i)||/||b|| 3.161480347603e-05
  53 KSP unpreconditioned resid norm 1.184791772965e-03 true resid norm 
1.184791772965e-03 ||r(i)||/||b|| 2.950934100844e-05
  54 KSP unpreconditioned resid norm 1.064535156080e-03 true resid norm 
1.064535156080e-03 ||r(i)||/||b|| 2.651413662135e-05
  55 KSP unpreconditioned resid norm 9.639036688120e-04 true resid norm 
9.639036688117e-04 ||r(i)||/||b|| 2.400773090370e-05
  56 KSP unpreconditioned resid norm 8.632359780260e-04 true resid norm 
8.632359780260e-04 ||r(i)||/||b|| 2.150042347322e-05
  57 KSP unpreconditioned resid norm 7.613605783850e-04 true resid norm 
7.613605783850e-04 ||r(i)||/||b|| 1.896303591113e-05
  58 KSP unpreconditioned resid norm 6.681073248348e-04 true resid norm 
6.681073248349e-04 ||r(i)||/||b|| 1.664039819373e-05
  59 KSP unpreconditioned resid norm 5.656127908544e-04 true resid norm 
5.656127908545e-04 ||r(i)||/||b|| 1.408758999254e-05
  60 KSP unpreconditioned resid norm 4.850863370767e-04 true resid norm 
4.850863370767e-04 ||r(i)||/||b|| 1.208193580169e-05
  61 KSP unpreconditioned resid norm 4.374055762320e-04 true resid norm 
4.374055762316e-04 ||r(i)||/||b|| 1.089436186387e-05
  62 KSP unpreconditioned resid norm 3.874398257079e-04 true resid norm 
3.874398257077e-04 ||r(i)||/||b|| 9.649876204364e-06
  63 KSP unpreconditioned resid norm 3.364908694427e-04 true resid norm 
3.364908694429e-04 ||r(i)||/||b|| 8.380902061609e-06
  64 KSP unpreconditioned resid norm 2.961034697265e-04 true resid norm 
2.961034697268e-04 ||r(i)||/||b|| 7.374982221632e-06
  65 KSP unpreconditioned resid norm 2.640593092764e-04 true resid norm 
2.640593092767e-04 ||r(i)||/||b|| 6.576865557059e-06
  66 KSP unpreconditioned resid norm 2.423231125743e-04 true resid norm 
2.423231125745e-04 ||r(i)||/||b|| 6.035487016671e-06
  67 KSP unpreconditioned resid norm 2.182349471179e-04 true resid norm 
2.182349471179e-04 ||r(i)||/||b|| 5.435528521898e-06
  68 KSP unpreconditioned resid norm 2.008438265031e-04 true resid norm 
2.008438265028e-04 ||r(i)||/||b|| 5.002371809927e-06
  69 KSP unpreconditioned resid norm 1.838732863386e-04 true resid norm 
1.838732863388e-04 ||r(i)||/||b|| 4.579690400226e-06
  70 KSP unpreconditioned resid norm 1.723786027645e-04 true resid norm 
1.723786027645e-04 ||r(i)||/||b|| 4.293394913444e-06
  71 KSP unpreconditioned resid norm 1.580945192204e-04 true resid norm 
1.580945192205e-04 ||r(i)||/||b|| 3.937624471826e-06
  72 KSP unpreconditioned resid norm 1.476687469671e-04 true resid norm 
1.476687469671e-04 ||r(i)||/||b|| 3.677952117812e-06
  73 KSP unpreconditioned resid norm 1.385018526182e-04 true resid norm 
1.385018526184e-04 ||r(i)||/||b|| 3.449634351350e-06
  74 KSP unpreconditioned resid norm 1.279712893541e-04 true resid norm 
1.279712893541e-04 ||r(i)||/||b|| 3.187351991305e-06
  75 KSP unpreconditioned resid norm 1.202010411772e-04 true resid norm 
1.202010411774e-04 ||r(i)||/||b|| 2.993820175504e-06
  76 KSP unpreconditioned resid norm 1.113459414198e-04 true resid norm 
1.113459414200e-04 ||r(i)||/||b|| 2.773268206485e-06
  77 KSP unpreconditioned resid norm 1.042523036036e-04 true resid norm 
1.042523036037e-04 ||r(i)||/||b|| 2.596588572066e-06
  78 KSP unpreconditioned resid norm 9.565176453232e-05 true resid norm 
9.565176453227e-05 ||r(i)||/||b|| 2.382376888539e-06
  79 KSP unpreconditioned resid norm 8.896901670359e-05 true resid norm 
8.896901670365e-05 ||r(i)||/||b|| 2.215931198209e-06
  80 KSP unpreconditioned resid norm 8.119298425803e-05 true resid norm 
8.119298425824e-05 ||r(i)||/||b|| 2.022255314935e-06
  81 KSP unpreconditioned resid norm 7.544528309154e-05 true resid norm 
7.544528309154e-05 ||r(i)||/||b|| 1.879098620558e-06
  82 KSP unpreconditioned resid norm 6.755385041138e-05 true resid norm 
6.755385041176e-05 ||r(i)||/||b|| 1.682548489719e-06
  83 KSP unpreconditioned resid norm 6.158629300870e-05 true resid norm 
6.158629300835e-05 ||r(i)||/||b|| 1.533915885727e-06
  84 KSP unpreconditioned resid norm 5.358756885754e-05 true resid norm 
5.358756885765e-05 ||r(i)||/||b|| 1.334693470462e-06
  85 KSP unpreconditioned resid norm 4.774852370380e-05 true resid norm 
4.774852370387e-05 ||r(i)||/||b|| 1.189261692037e-06
  86 KSP unpreconditioned resid norm 3.919358737908e-05 true resid norm 
3.919358737930e-05 ||r(i)||/||b|| 9.761858258229e-07
  87 KSP unpreconditioned resid norm 3.434042319950e-05 true resid norm 
3.434042319947e-05 ||r(i)||/||b|| 8.553091620745e-07
  88 KSP unpreconditioned resid norm 2.813699436281e-05 true resid norm 
2.813699436302e-05 ||r(i)||/||b|| 7.008017615898e-07
  89 KSP unpreconditioned resid norm 2.462248069068e-05 true resid norm 
2.462248069051e-05 ||r(i)||/||b|| 6.132665635851e-07
  90 KSP unpreconditioned resid norm 2.040558789626e-05 true resid norm 
2.040558789626e-05 ||r(i)||/||b|| 5.082373674841e-07
  91 KSP unpreconditioned resid norm 1.888523204468e-05 true resid norm 
1.888523204470e-05 ||r(i)||/||b|| 4.703702077842e-07
  92 KSP unpreconditioned resid norm 1.707071292484e-05 true resid norm 
1.707071292474e-05 ||r(i)||/||b|| 4.251763900191e-07
  93 KSP unpreconditioned resid norm 1.498636454665e-05 true resid norm 
1.498636454672e-05 ||r(i)||/||b|| 3.732619958859e-07
  94 KSP unpreconditioned resid norm 1.219393542993e-05 true resid norm 
1.219393543006e-05 ||r(i)||/||b|| 3.037115947725e-07
  95 KSP unpreconditioned resid norm 1.059996963300e-05 true resid norm 
1.059996963303e-05 ||r(i)||/||b|| 2.640110487917e-07
  96 KSP unpreconditioned resid norm 9.099659872548e-06 true resid norm 
9.099659873214e-06 ||r(i)||/||b|| 2.266431725699e-07
  97 KSP unpreconditioned resid norm 8.147347587295e-06 true resid norm 
8.147347587584e-06 ||r(i)||/||b|| 2.029241456283e-07
  98 KSP unpreconditioned resid norm 7.167226146744e-06 true resid norm 
7.167226146783e-06 ||r(i)||/||b|| 1.785124823418e-07
  99 KSP unpreconditioned resid norm 6.552540209538e-06 true resid norm 
6.552540209577e-06 ||r(i)||/||b|| 1.632026385802e-07
100 KSP unpreconditioned resid norm 5.767783600111e-06 true resid norm 
5.767783600320e-06 ||r(i)||/||b|| 1.436568830140e-07
101 KSP unpreconditioned resid norm 5.261057430584e-06 true resid norm 
5.261057431144e-06 ||r(i)||/||b|| 1.310359688033e-07
102 KSP unpreconditioned resid norm 4.715498525786e-06 true resid norm 
4.715498525947e-06 ||r(i)||/||b|| 1.174478564100e-07
103 KSP unpreconditioned resid norm 4.380052669622e-06 true resid norm 
4.380052669825e-06 ||r(i)||/||b|| 1.090929822591e-07
104 KSP unpreconditioned resid norm 3.911664470060e-06 true resid norm 
3.911664470226e-06 ||r(i)||/||b|| 9.742694319496e-08
105 KSP unpreconditioned resid norm 3.652211458315e-06 true resid norm 
3.652211458259e-06 ||r(i)||/||b|| 9.096480564430e-08
106 KSP unpreconditioned resid norm 3.387532128049e-06 true resid norm 
3.387532128358e-06 ||r(i)||/||b|| 8.437249737363e-08
107 KSP unpreconditioned resid norm 3.234218880987e-06 true resid norm 
3.234218880798e-06 ||r(i)||/||b|| 8.055395895481e-08
108 KSP unpreconditioned resid norm 3.016905196388e-06 true resid norm 
3.016905196492e-06 ||r(i)||/||b|| 7.514137611763e-08
109 KSP unpreconditioned resid norm 2.858246441921e-06 true resid norm 
2.858246441975e-06 ||r(i)||/||b|| 7.118969836476e-08
110 KSP unpreconditioned resid norm 2.637118810847e-06 true resid norm 
2.637118810750e-06 ||r(i)||/||b|| 6.568212241336e-08
111 KSP unpreconditioned resid norm 2.494976088717e-06 true resid norm 
2.494976088700e-06 ||r(i)||/||b|| 6.214180574966e-08
112 KSP unpreconditioned resid norm 2.270639574272e-06 true resid norm 
2.270639574200e-06 ||r(i)||/||b|| 5.655430686750e-08
113 KSP unpreconditioned resid norm 2.104988663813e-06 true resid norm 
2.104988664169e-06 ||r(i)||/||b|| 5.242847707696e-08
114 KSP unpreconditioned resid norm 1.889361127301e-06 true resid norm 
1.889361127526e-06 ||r(i)||/||b|| 4.705789073868e-08
115 KSP unpreconditioned resid norm 1.732367008052e-06 true resid norm 
1.732367007971e-06 ||r(i)||/||b|| 4.314767367271e-08
116 KSP unpreconditioned resid norm 1.509288268391e-06 true resid norm 
1.509288268645e-06 ||r(i)||/||b|| 3.759150191264e-08
117 KSP unpreconditioned resid norm 1.359169217644e-06 true resid norm 
1.359169217445e-06 ||r(i)||/||b|| 3.385252062089e-08
118 KSP unpreconditioned resid norm 1.180146337735e-06 true resid norm 
1.180146337908e-06 ||r(i)||/||b|| 2.939363820703e-08
119 KSP unpreconditioned resid norm 1.067757039683e-06 true resid norm 
1.067757039924e-06 ||r(i)||/||b|| 2.659438335433e-08
120 KSP unpreconditioned resid norm 9.435833073736e-07 true resid norm 
9.435833073736e-07 ||r(i)||/||b|| 2.350161625235e-08
121 KSP unpreconditioned resid norm 8.749457237613e-07 true resid norm 
8.749457236791e-07 ||r(i)||/||b|| 2.179207546261e-08
122 KSP unpreconditioned resid norm 7.945760150897e-07 true resid norm 
7.945760150444e-07 ||r(i)||/||b|| 1.979032528762e-08
123 KSP unpreconditioned resid norm 7.141240839013e-07 true resid norm 
7.141240838682e-07 ||r(i)||/||b|| 1.778652721438e-08
124 KSP unpreconditioned resid norm 6.300566936733e-07 true resid norm 
6.300566936607e-07 ||r(i)||/||b|| 1.569267971988e-08
125 KSP unpreconditioned resid norm 5.628986997544e-07 true resid norm 
5.628986995849e-07 ||r(i)||/||b|| 1.401999073448e-08
126 KSP unpreconditioned resid norm 5.119018951602e-07 true resid norm 
5.119018951837e-07 ||r(i)||/||b|| 1.274982484900e-08
127 KSP unpreconditioned resid norm 4.664670343748e-07 true resid norm 
4.664670344042e-07 ||r(i)||/||b|| 1.161818903670e-08
128 KSP unpreconditioned resid norm 4.253264691112e-07 true resid norm 
4.253264691948e-07 ||r(i)||/||b|| 1.059351027394e-08
129 KSP unpreconditioned resid norm 3.868921150516e-07 true resid norm 
3.868921150517e-07 ||r(i)||/||b|| 9.636234498800e-09
130 KSP unpreconditioned resid norm 3.558445658540e-07 true resid norm 
3.558445660061e-07 ||r(i)||/||b|| 8.862940209315e-09
131 KSP unpreconditioned resid norm 3.268710273840e-07 true resid norm 
3.268710272455e-07 ||r(i)||/||b|| 8.141302825416e-09
132 KSP unpreconditioned resid norm 3.041273897592e-07 true resid norm 
3.041273896694e-07 ||r(i)||/||b|| 7.574832182794e-09
133 KSP unpreconditioned resid norm 2.851926677922e-07 true resid norm 
2.851926674248e-07 ||r(i)||/||b|| 7.103229333782e-09
134 KSP unpreconditioned resid norm 2.694708315072e-07 true resid norm 
2.694708309500e-07 ||r(i)||/||b|| 6.711649104748e-09
135 KSP unpreconditioned resid norm 2.534825559099e-07 true resid norm 
2.534825557469e-07 ||r(i)||/||b|| 6.313432746507e-09
136 KSP unpreconditioned resid norm 2.387342352458e-07 true resid norm 
2.387342351804e-07 ||r(i)||/||b|| 5.946099658254e-09
137 KSP unpreconditioned resid norm 2.200861667617e-07 true resid norm 
2.200861665255e-07 ||r(i)||/||b|| 5.481636425438e-09
138 KSP unpreconditioned resid norm 2.051415370616e-07 true resid norm 
2.051415370614e-07 ||r(i)||/||b|| 5.109413915824e-09
139 KSP unpreconditioned resid norm 1.887376429396e-07 true resid norm 
1.887376426682e-07 ||r(i)||/||b|| 4.700845824315e-09
140 KSP unpreconditioned resid norm 1.729743133005e-07 true resid norm 
1.729743128342e-07 ||r(i)||/||b|| 4.308232129561e-09
141 KSP unpreconditioned resid norm 1.541021130781e-07 true resid norm 
1.541021128364e-07 ||r(i)||/||b|| 3.838186508023e-09
142 KSP unpreconditioned resid norm 1.384631628565e-07 true resid norm 
1.384631627735e-07 ||r(i)||/||b|| 3.448670712125e-09
143 KSP unpreconditioned resid norm 1.223114405626e-07 true resid norm 
1.223114403883e-07 ||r(i)||/||b|| 3.046383411846e-09
144 KSP unpreconditioned resid norm 1.087313066223e-07 true resid norm 
1.087313065117e-07 ||r(i)||/||b|| 2.708146085550e-09
145 KSP unpreconditioned resid norm 9.181901998734e-08 true resid norm 
9.181901984268e-08 ||r(i)||/||b|| 2.286915582489e-09
146 KSP unpreconditioned resid norm 7.885850510808e-08 true resid norm 
7.885850531446e-08 ||r(i)||/||b|| 1.964110975313e-09
147 KSP unpreconditioned resid norm 6.483393946950e-08 true resid norm 
6.483393931383e-08 ||r(i)||/||b|| 1.614804278515e-09
148 KSP unpreconditioned resid norm 5.690132597004e-08 true resid norm 
5.690132577518e-08 ||r(i)||/||b|| 1.417228465328e-09
149 KSP unpreconditioned resid norm 5.023671521579e-08 true resid norm 
5.023671502186e-08 ||r(i)||/||b|| 1.251234511035e-09
150 KSP unpreconditioned resid norm 4.625371062660e-08 true resid norm 
4.625371062660e-08 ||r(i)||/||b|| 1.152030720445e-09
151 KSP unpreconditioned resid norm 4.349049084805e-08 true resid norm 
4.349049089337e-08 ||r(i)||/||b|| 1.083207830846e-09
152 KSP unpreconditioned resid norm 3.932593324498e-08 true resid norm 
3.932593376918e-08 ||r(i)||/||b|| 9.794821474546e-10
153 KSP unpreconditioned resid norm 3.504167649202e-08 true resid norm 
3.504167638113e-08 ||r(i)||/||b|| 8.727751166356e-10
154 KSP unpreconditioned resid norm 2.892726347747e-08 true resid norm 
2.892726348583e-08 ||r(i)||/||b|| 7.204848160858e-10
155 KSP unpreconditioned resid norm 2.477647033202e-08 true resid norm 
2.477647041570e-08 ||r(i)||/||b|| 6.171019508795e-10
156 KSP unpreconditioned resid norm 2.128504065757e-08 true resid norm 
2.128504067423e-08 ||r(i)||/||b|| 5.301416991298e-10
157 KSP unpreconditioned resid norm 1.879248809429e-08 true resid norm 
1.879248818928e-08 ||r(i)||/||b|| 4.680602575310e-10
158 KSP unpreconditioned resid norm 1.673649140073e-08 true resid norm 
1.673649134005e-08 ||r(i)||/||b|| 4.168520085200e-10
159 KSP unpreconditioned resid norm 1.497123388109e-08 true resid norm 
1.497123365569e-08 ||r(i)||/||b|| 3.728851342016e-10
160 KSP unpreconditioned resid norm 1.315982130162e-08 true resid norm 
1.315982149329e-08 ||r(i)||/||b|| 3.277687007261e-10
161 KSP unpreconditioned resid norm 1.182395864938e-08 true resid norm 
1.182395868430e-08 ||r(i)||/||b|| 2.944966675550e-10
162 KSP unpreconditioned resid norm 1.070204481679e-08 true resid norm 
1.070204466432e-08 ||r(i)||/||b|| 2.665534085342e-10
163 KSP unpreconditioned resid norm 9.969290307649e-09 true resid norm 
9.969290432333e-09 ||r(i)||/||b|| 2.483028644297e-10
164 KSP unpreconditioned resid norm 9.134440883306e-09 true resid norm 
9.134440980976e-09 ||r(i)||/||b|| 2.275094577628e-10
165 KSP unpreconditioned resid norm 8.593316427292e-09 true resid norm 
8.593316413360e-09 ||r(i)||/||b|| 2.140317904139e-10
166 KSP unpreconditioned resid norm 8.042173048464e-09 true resid norm 
8.042173332848e-09 ||r(i)||/||b|| 2.003045942277e-10
167 KSP unpreconditioned resid norm 7.655518522782e-09 true resid norm 
7.655518879144e-09 ||r(i)||/||b|| 1.906742791064e-10
168 KSP unpreconditioned resid norm 7.210283391815e-09 true resid norm 
7.210283220312e-09 ||r(i)||/||b|| 1.795848951442e-10
169 KSP unpreconditioned resid norm 6.793967416271e-09 true resid norm 
6.793967448832e-09 ||r(i)||/||b|| 1.692158122825e-10
170 KSP unpreconditioned resid norm 6.249160304588e-09 true resid norm 
6.249160382647e-09 ||r(i)||/||b|| 1.556464257736e-10
171 KSP unpreconditioned resid norm 5.794936438798e-09 true resid norm 
5.794936332552e-09 ||r(i)||/||b|| 1.443331699811e-10
172 KSP unpreconditioned resid norm 5.222337397128e-09 true resid norm 
5.222337443277e-09 ||r(i)||/||b|| 1.300715788135e-10
173 KSP unpreconditioned resid norm 4.755359110447e-09 true resid norm 
4.755358888996e-09 ||r(i)||/||b|| 1.184406494668e-10
174 KSP unpreconditioned resid norm 4.317537007873e-09 true resid norm 
4.317537267718e-09 ||r(i)||/||b|| 1.075359252630e-10
175 KSP unpreconditioned resid norm 3.924177535665e-09 true resid norm 
3.924177629720e-09 ||r(i)||/||b|| 9.773860563138e-11
176 KSP unpreconditioned resid norm 3.502843065115e-09 true resid norm 
3.502843126359e-09 ||r(i)||/||b|| 8.724452234855e-11
177 KSP unpreconditioned resid norm 3.083873232869e-09 true resid norm 
3.083873352938e-09 ||r(i)||/||b|| 7.680933686007e-11
178 KSP unpreconditioned resid norm 2.758980676473e-09 true resid norm 
2.758980618096e-09 ||r(i)||/||b|| 6.871730691658e-11
179 KSP unpreconditioned resid norm 2.510978240429e-09 true resid norm 
2.510978327392e-09 ||r(i)||/||b|| 6.254036989334e-11
180 KSP unpreconditioned resid norm 2.323000193205e-09 true resid norm 
2.323000193205e-09 ||r(i)||/||b|| 5.785844097519e-11
181 KSP unpreconditioned resid norm 2.167480159274e-09 true resid norm 
2.167480113693e-09 ||r(i)||/||b|| 5.398493749153e-11
182 KSP unpreconditioned resid norm 1.983545827983e-09 true resid norm 
1.983546404840e-09 ||r(i)||/||b|| 4.940374216139e-11
183 KSP unpreconditioned resid norm 1.794576286774e-09 true resid norm 
1.794576224361e-09 ||r(i)||/||b|| 4.469710457036e-11
184 KSP unpreconditioned resid norm 1.583490590644e-09 true resid norm 
1.583490380603e-09 ||r(i)||/||b|| 3.943963715064e-11
185 KSP unpreconditioned resid norm 1.412659866247e-09 true resid norm 
1.412659832191e-09 ||r(i)||/||b|| 3.518479927722e-11
186 KSP unpreconditioned resid norm 1.285613344939e-09 true resid norm 
1.285612984761e-09 ||r(i)||/||b|| 3.202047215205e-11
187 KSP unpreconditioned resid norm 1.168115133929e-09 true resid norm 
1.168114766904e-09 ||r(i)||/||b|| 2.909397058634e-11
188 KSP unpreconditioned resid norm 1.063377926053e-09 true resid norm 
1.063377647554e-09 ||r(i)||/||b|| 2.648530681802e-11
189 KSP unpreconditioned resid norm 9.548967728122e-10 true resid norm 
9.548964523410e-10 ||r(i)||/||b|| 2.378339019807e-11
KSP Object: 16 MPI processes
   type: fgmres
     restart=30, using Classical (unmodified) Gram-Schmidt 
Orthogonalization with no iterative refinement
     happy breakdown tolerance 1e-30
   maximum iterations=2000, initial guess is zero
   tolerances:  relative=1e-20, absolute=1e-09, divergence=10000.
   right preconditioning
   using UNPRECONDITIONED norm type for convergence test
PC Object: 16 MPI processes
   type: bjacobi
     number of blocks = 4
     Local solver information for first block is in the following KSP 
and PC objects on rank 0:
     Use -ksp_view ::ascii_info_detail to display information for all blocks
   KSP Object: (sub_) 4 MPI processes
     type: preonly
     maximum iterations=10000, initial guess is zero
     tolerances:  relative=1e-05, absolute=1e-50, divergence=10000.
     left preconditioning
     using NONE norm type for convergence test
   PC Object: (sub_) 4 MPI processes
     type: telescope
       petsc subcomm: parent comm size reduction factor = 4
       petsc subcomm: parent_size = 4 , subcomm_size = 1
       petsc subcomm type = contiguous
     linear system matrix = precond matrix:
     Mat Object: (sub_) 4 MPI processes
       type: mpiaij
       rows=40200, cols=40200
       total: nonzeros=199996, allocated nonzeros=203412
       total number of mallocs used during MatSetValues calls=0
         not using I-node (on process 0) routines
         setup type: default
         Parent DM object: NULL
         Sub DM object: NULL
         KSP Object:   (sub_telescope_)   1 MPI processes
           type: preonly
           maximum iterations=10000, initial guess is zero
           tolerances:  relative=1e-05, absolute=1e-50, divergence=10000.
           left preconditioning
           using NONE norm type for convergence test
         PC Object:   (sub_telescope_)   1 MPI processes
           type: lu
             out-of-place factorization
             tolerance for zero pivot 2.22045e-14
             matrix ordering: external
             factor fill ratio given 0., needed 0.
               Factored matrix follows:
                 Mat Object:   1 MPI processes
                   type: mumps
                   rows=40200, cols=40200
                   package used to perform factorization: mumps
                   total: nonzeros=1849788, allocated nonzeros=1849788
                     MUMPS run parameters:
                       SYM (matrix type):                   0
                       PAR (host participation):            1
                       ICNTL(1) (output for error):         6
                       ICNTL(2) (output of diagnostic msg): 0
                       ICNTL(3) (output for global info):   0
                       ICNTL(4) (level of printing):        0
                       ICNTL(5) (input mat struct):         0
                       ICNTL(6) (matrix prescaling):        7
                       ICNTL(7) (sequential matrix ordering):7
                       ICNTL(8) (scaling strategy):        77
                       ICNTL(10) (max num of refinements):  0
                       ICNTL(11) (error analysis):          0
                       ICNTL(12) (efficiency control): 
        1
                       ICNTL(13) (sequential factorization of the root 
node):  0
                       ICNTL(14) (percentage of estimated workspace 
increase): 20
                       ICNTL(18) (input mat struct): 
        0
                       ICNTL(19) (Schur complement info): 
        0
                       ICNTL(20) (RHS sparse pattern): 
        0
                       ICNTL(21) (solution struct): 
        0
                       ICNTL(22) (in-core/out-of-core facility): 
        0
                       ICNTL(23) (max size of memory can be allocated 
locally):0
                       ICNTL(24) (detection of null pivot rows): 
        0
                       ICNTL(25) (computation of a null space basis): 
        0
                       ICNTL(26) (Schur options for RHS or solution): 
        0
                       ICNTL(27) (blocking size for multiple RHS): 
        -32
                       ICNTL(28) (use parallel or sequential ordering): 
        1
                       ICNTL(29) (parallel ordering): 
        0
                       ICNTL(30) (user-specified set of entries in 
inv(A)):    0
                       ICNTL(31) (factors is discarded in the solve 
phase):    0
                       ICNTL(33) (compute determinant): 
        0
                       ICNTL(35) (activate BLR based factorization): 
        0
                       ICNTL(36) (choice of BLR factorization variant): 
        0
                       ICNTL(38) (estimated compression rate of LU 
factors):   333
                       CNTL(1) (relative pivoting threshold):      0.01
                       CNTL(2) (stopping criterion of refinement): 
1.49012e-08
                       CNTL(3) (absolute pivoting threshold):      0.
                       CNTL(4) (value of static pivoting):         -1.
                       CNTL(5) (fixation for null pivots):         0.
                       CNTL(7) (dropping parameter for BLR):       0.
                       RINFO(1) (local estimated flops for the 
elimination after analysis):
                         [0] 1.45525e+08
                       RINFO(2) (local estimated flops for the assembly 
after factorization):
                         [0]  2.89397e+06
                       RINFO(3) (local estimated flops for the 
elimination after factorization):
                         [0]  1.45525e+08
                       INFO(15) (estimated size of (in MB) MUMPS 
internal data for running numerical factorization):
                       [0] 29
                       INFO(16) (size of (in MB) MUMPS internal data 
used during numerical factorization):
                         [0] 29
                       INFO(23) (num of pivots eliminated on this 
processor after factorization):
                         [0] 40200
                       RINFOG(1) (global estimated flops for the 
elimination after analysis): 1.45525e+08
                       RINFOG(2) (global estimated flops for the 
assembly after factorization): 2.89397e+06
                       RINFOG(3) (global estimated flops for the 
elimination after factorization): 1.45525e+08
                       (RINFOG(12) RINFOG(13))*2^INFOG(34) 
(determinant): (0.,0.)*(2^0)
                       INFOG(3) (estimated real workspace for factors on 
all processors after analysis): 1849788
                       INFOG(4) (estimated integer workspace for factors 
on all processors after analysis): 879986
                       INFOG(5) (estimated maximum front size in the 
complete tree): 282
                       INFOG(6) (number of nodes in the complete tree): 
23709
                       INFOG(7) (ordering option effectively used after 
analysis): 5
                       INFOG(8) (structural symmetry in percent of the 
permuted matrix after analysis): 100
                       INFOG(9) (total real/complex workspace to store 
the matrix factors after factorization): 1849788
                       INFOG(10) (total integer space store the matrix 
factors after factorization): 879986
                       INFOG(11) (order of largest frontal matrix after 
factorization): 282
                       INFOG(12) (number of off-diagonal pivots): 0
                       INFOG(13) (number of delayed pivots after 
factorization): 0
                       INFOG(14) (number of memory compress after 
factorization): 0
                       INFOG(15) (number of steps of iterative 
refinement after solution): 0
                       INFOG(16) (estimated size (in MB) of all MUMPS 
internal data for factorization after analysis: value on the most memory 
consuming processor): 29
                       INFOG(17) (estimated size of all MUMPS internal 
data for factorization after analysis: sum over all processors): 29
                       INFOG(18) (size of all MUMPS internal data 
allocated during factorization: value on the most memory consuming 
processor): 29
                       INFOG(19) (size of all MUMPS internal data 
allocated during factorization: sum over all processors): 29
                       INFOG(20) (estimated number of entries in the 
factors): 1849788
                       INFOG(21) (size in MB of memory effectively used 
during factorization - value on the most memory consuming processor): 26
                       INFOG(22) (size in MB of memory effectively used 
during factorization - sum over all processors): 26
                       INFOG(23) (after analysis: value of ICNTL(6) 
effectively used): 0
                       INFOG(24) (after analysis: value of ICNTL(12) 
effectively used): 1
                       INFOG(25) (after factorization: number of pivots 
modified by static pivoting): 0
                       INFOG(28) (after factorization: number of null 
pivots encountered): 0
                       INFOG(29) (after factorization: effective number 
of entries in the factors (sum over all processors)): 1849788
                       INFOG(30, 31) (after solution: size in Mbytes of 
memory used during solution phase): 29, 29
                       INFOG(32) (after analysis: type of analysis done): 1
                       INFOG(33) (value used for ICNTL(8)): 7
                       INFOG(34) (exponent of the determinant if 
determinant is requested): 0
                       INFOG(35) (after factorization: number of entries 
taking into account BLR factor compression - sum over all processors): 
1849788
                       INFOG(36) (after analysis: estimated size of all 
MUMPS internal data for running BLR in-core - value on the most memory 
consuming processor): 0
                       INFOG(37) (after analysis: estimated size of all 
MUMPS internal data for running BLR in-core - sum over all processors): 0
                       INFOG(38) (after analysis: estimated size of all 
MUMPS internal data for running BLR out-of-core - value on the most 
memory consuming processor): 0
                       INFOG(39) (after analysis: estimated size of all 
MUMPS internal data for running BLR out-of-core - sum over all 
processors): 0
           linear system matrix = precond matrix:
           Mat Object:   1 MPI processes
             type: seqaijcusparse
             rows=40200, cols=40200
             total: nonzeros=199996, allocated nonzeros=199996
             total number of mallocs used during MatSetValues calls=0
               not using I-node routines
   linear system matrix = precond matrix:
   Mat Object: 16 MPI processes
     type: mpiaijcusparse
     rows=160800, cols=160800
     total: nonzeros=802396, allocated nonzeros=1608000
     total number of mallocs used during MatSetValues calls=0
       not using I-node (on process 0) routines
Norm of error 9.11684e-07 iterations 189

Chang



On 10/14/21 10:10 PM, Chang Liu wrote:
> Hi Barry,
> 
> No problem. Here is the output. It seems that the resid norm calculation 
> is incorrect.
> 
> $ mpiexec -n 16 --hostfile hostfile --oversubscribe ./ex7 -m 400 
> -ksp_view -ksp_monitor_true_residual -pc_type bjacobi -pc_bjacobi_blocks 
> 4 -ksp_type fgmres -mat_type aijcusparse -sub_pc_type telescope 
> -sub_ksp_type preonly -sub_telescope_ksp_type preonly 
> -sub_telescope_pc_type lu -sub_telescope_pc_factor_mat_solver_type 
> cusparse -sub_pc_telescope_reduction_factor 4 
> -sub_pc_telescope_subcomm_type contiguous -ksp_max_it 2000 -ksp_rtol 
> 1.e-20 -ksp_atol 1.e-9
>    0 KSP unpreconditioned resid norm 4.014971979977e+01 true resid norm 
> 4.014971979977e+01 ||r(i)||/||b|| 1.000000000000e+00
>    1 KSP unpreconditioned resid norm 0.000000000000e+00 true resid norm 
> 4.014971979977e+01 ||r(i)||/||b|| 1.000000000000e+00
> KSP Object: 16 MPI processes
>    type: fgmres
>      restart=30, using Classical (unmodified) Gram-Schmidt 
> Orthogonalization with no iterative refinement
>      happy breakdown tolerance 1e-30
>    maximum iterations=2000, initial guess is zero
>    tolerances:  relative=1e-20, absolute=1e-09, divergence=10000.
>    right preconditioning
>    using UNPRECONDITIONED norm type for convergence test
> PC Object: 16 MPI processes
>    type: bjacobi
>      number of blocks = 4
>      Local solver information for first block is in the following KSP 
> and PC objects on rank 0:
>      Use -ksp_view ::ascii_info_detail to display information for all 
> blocks
>    KSP Object: (sub_) 4 MPI processes
>      type: preonly
>      maximum iterations=10000, initial guess is zero
>      tolerances:  relative=1e-05, absolute=1e-50, divergence=10000.
>      left preconditioning
>      using NONE norm type for convergence test
>    PC Object: (sub_) 4 MPI processes
>      type: telescope
>        petsc subcomm: parent comm size reduction factor = 4
>        petsc subcomm: parent_size = 4 , subcomm_size = 1
>        petsc subcomm type = contiguous
>      linear system matrix = precond matrix:
>      Mat Object: (sub_) 4 MPI processes
>        type: mpiaij
>        rows=40200, cols=40200
>        total: nonzeros=199996, allocated nonzeros=203412
>        total number of mallocs used during MatSetValues calls=0
>          not using I-node (on process 0) routines
>          setup type: default
>          Parent DM object: NULL
>          Sub DM object: NULL
>          KSP Object:   (sub_telescope_)   1 MPI processes
>            type: preonly
>            maximum iterations=10000, initial guess is zero
>            tolerances:  relative=1e-05, absolute=1e-50, divergence=10000.
>            left preconditioning
>            using NONE norm type for convergence test
>          PC Object:   (sub_telescope_)   1 MPI processes
>            type: lu
>              out-of-place factorization
>              tolerance for zero pivot 2.22045e-14
>              matrix ordering: nd
>              factor fill ratio given 5., needed 8.62558
>                Factored matrix follows:
>                  Mat Object:   1 MPI processes
>                    type: seqaijcusparse
>                    rows=40200, cols=40200
>                    package used to perform factorization: cusparse
>                    total: nonzeros=1725082, allocated nonzeros=1725082
>                      not using I-node routines
>            linear system matrix = precond matrix:
>            Mat Object:   1 MPI processes
>              type: seqaijcusparse
>              rows=40200, cols=40200
>              total: nonzeros=199996, allocated nonzeros=199996
>              total number of mallocs used during MatSetValues calls=0
>                not using I-node routines
>    linear system matrix = precond matrix:
>    Mat Object: 16 MPI processes
>      type: mpiaijcusparse
>      rows=160800, cols=160800
>      total: nonzeros=802396, allocated nonzeros=1608000
>      total number of mallocs used during MatSetValues calls=0
>        not using I-node (on process 0) routines
> Norm of error 400.999 iterations 1
> 
> Chang
> 
> 
> On 10/14/21 9:47 PM, Barry Smith wrote:
>>
>>    Chang,
>>
>>     Sorry I did not notice that one. Please run that with -ksp_view 
>> -ksp_monitor_true_residual so we can see exactly how options are 
>> interpreted and solver used. At a glance it looks ok but something 
>> must be wrong to get the wrong answer.
>>
>>    Barry
>>
>>> On Oct 14, 2021, at 6:02 PM, Chang Liu <cliu at pppl.gov> wrote:
>>>
>>> Hi Barry,
>>>
>>> That is exactly what I was doing in the second example, in which the 
>>> preconditioner works but the GMRES does not.
>>>
>>> Chang
>>>
>>> On 10/14/21 5:15 PM, Barry Smith wrote:
>>>>    You need to use the PCTELESCOPE inside the block Jacobi, not 
>>>> outside it. So something like -pc_type bjacobi -sub_pc_type 
>>>> telescope -sub_telescope_pc_type lu
>>>>> On Oct 14, 2021, at 4:14 PM, Chang Liu <cliu at pppl.gov> wrote:
>>>>>
>>>>> Hi Pierre,
>>>>>
>>>>> I wonder if the trick of PCTELESCOPE only works for preconditioner 
>>>>> and not for the solver. I have done some tests, and find that for 
>>>>> solving a small matrix using -telescope_ksp_type preonly, it does 
>>>>> work for GPU with multiple MPI processes. However, for bjacobi and 
>>>>> gmres, it does not work.
>>>>>
>>>>> The command line options I used for small matrix is like
>>>>>
>>>>> mpiexec -n 4 --oversubscribe ./ex7 -m 100 -ksp_monitor_short 
>>>>> -pc_type telescope -mat_type aijcusparse -telescope_pc_type lu 
>>>>> -telescope_pc_factor_mat_solver_type cusparse -telescope_ksp_type 
>>>>> preonly -pc_telescope_reduction_factor 4
>>>>>
>>>>> which gives the correct output. For iterative solver, I tried
>>>>>
>>>>> mpiexec -n 16 --oversubscribe ./ex7 -m 400 -ksp_monitor_short 
>>>>> -pc_type bjacobi -pc_bjacobi_blocks 4 -ksp_type fgmres -mat_type 
>>>>> aijcusparse -sub_pc_type telescope -sub_ksp_type preonly 
>>>>> -sub_telescope_ksp_type preonly -sub_telescope_pc_type lu 
>>>>> -sub_telescope_pc_factor_mat_solver_type cusparse 
>>>>> -sub_pc_telescope_reduction_factor 4 -ksp_max_it 2000 -ksp_rtol 
>>>>> 1.e-9 -ksp_atol 1.e-20
>>>>>
>>>>> for large matrix. The output is like
>>>>>
>>>>>   0 KSP Residual norm 40.1497
>>>>>   1 KSP Residual norm < 1.e-11
>>>>> Norm of error 400.999 iterations 1
>>>>>
>>>>> So it seems to call a direct solver instead of an iterative one.
>>>>>
>>>>> Can you please help check these options?
>>>>>
>>>>> Chang
>>>>>
>>>>> On 10/14/21 10:04 AM, Pierre Jolivet wrote:
>>>>>>> On 14 Oct 2021, at 3:50 PM, Chang Liu <cliu at pppl.gov> wrote:
>>>>>>>
>>>>>>> Thank you Pierre. I was not aware of PCTELESCOPE before. This 
>>>>>>> sounds exactly what I need. I wonder if PCTELESCOPE can transform 
>>>>>>> a mpiaijcusparse to seqaircusparse? Or I have to do it manually?
>>>>>> PCTELESCOPE uses MatCreateMPIMatConcatenateSeqMat().
>>>>>> 1) I’m not sure this is implemented for cuSparse matrices, but it 
>>>>>> should be;
>>>>>> 2) at least for the implementations 
>>>>>> MatCreateMPIMatConcatenateSeqMat_MPIBAIJ() and 
>>>>>> MatCreateMPIMatConcatenateSeqMat_MPIAIJ(), the resulting MatType 
>>>>>> is MATBAIJ (resp. MATAIJ). Constructors are usually “smart” enough 
>>>>>> to detect if the MPI communicator on which the Mat lives is of 
>>>>>> size 1 (your case), and then the resulting Mat is of type MatSeqX 
>>>>>> instead of MatMPIX, so you would not need to worry about the 
>>>>>> transformation you are mentioning.
>>>>>> If you try this out and this does not work, please provide the 
>>>>>> backtrace (probably something like “Operation XYZ not implemented 
>>>>>> for MatType ABC”), and hopefully someone can add the missing 
>>>>>> plumbing.
>>>>>> I do not claim that this will be efficient, but I think this goes 
>>>>>> in the direction of what you want to achieve.
>>>>>> Thanks,
>>>>>> Pierre
>>>>>>> Chang
>>>>>>>
>>>>>>> On 10/14/21 1:35 AM, Pierre Jolivet wrote:
>>>>>>>> Maybe I’m missing something, but can’t you use PCTELESCOPE as a 
>>>>>>>> subdomain solver, with a reduction factor equal to the number of 
>>>>>>>> MPI processes you have per block?
>>>>>>>> -sub_pc_type telescope -sub_pc_telescope_reduction_factor X 
>>>>>>>> -sub_telescope_pc_type lu
>>>>>>>> This does not work with MUMPS -mat_mumps_use_omp_threads because 
>>>>>>>> not only do the Mat needs to be redistributed, the secondary 
>>>>>>>> processes also need to be “converted” to OpenMP threads.
>>>>>>>> Thus the need for specific code in mumps.c.
>>>>>>>> Thanks,
>>>>>>>> Pierre
>>>>>>>>> On 14 Oct 2021, at 6:00 AM, Chang Liu via petsc-users 
>>>>>>>>> <petsc-users at mcs.anl.gov> wrote:
>>>>>>>>>
>>>>>>>>> Hi Junchao,
>>>>>>>>>
>>>>>>>>> Yes that is what I want.
>>>>>>>>>
>>>>>>>>> Chang
>>>>>>>>>
>>>>>>>>> On 10/13/21 11:42 PM, Junchao Zhang wrote:
>>>>>>>>>> On Wed, Oct 13, 2021 at 8:58 PM Barry Smith <bsmith at petsc.dev 
>>>>>>>>>> <mailto:bsmith at petsc.dev>> wrote:
>>>>>>>>>>        Junchao,
>>>>>>>>>>           If I understand correctly Chang is using the block 
>>>>>>>>>> Jacobi
>>>>>>>>>>     method with a single block for a number of MPI ranks and a 
>>>>>>>>>> direct
>>>>>>>>>>     solver for each block so it uses 
>>>>>>>>>> PCSetUp_BJacobi_Multiproc() which
>>>>>>>>>>     is code Hong Zhang wrote a number of years ago for CPUs. 
>>>>>>>>>> For their
>>>>>>>>>>     particular problems this preconditioner works well, but 
>>>>>>>>>> using an
>>>>>>>>>>     iterative solver on the blocks does not work well.
>>>>>>>>>>           If we had complete MPI-GPU direct solvers he could 
>>>>>>>>>> just use
>>>>>>>>>>     the current code with MPIAIJCUSPARSE on each block but 
>>>>>>>>>> since we do
>>>>>>>>>>     not he would like to use a single GPU for each block, this 
>>>>>>>>>> means
>>>>>>>>>>     that diagonal blocks of  the global parallel MPI matrix 
>>>>>>>>>> needs to be
>>>>>>>>>>     sent to a subset of the GPUs (one GPU per block, which has 
>>>>>>>>>> multiple
>>>>>>>>>>     MPI ranks associated with the blocks). Similarly for the 
>>>>>>>>>> triangular
>>>>>>>>>>     solves the blocks of the right hand side needs to be 
>>>>>>>>>> shipped to the
>>>>>>>>>>     appropriate GPU and the resulting solution shipped back to 
>>>>>>>>>> the
>>>>>>>>>>     multiple GPUs. So Chang is absolutely correct, this is 
>>>>>>>>>> somewhat like
>>>>>>>>>>     your code for MUMPS with OpenMP. OK, I now understand the 
>>>>>>>>>> background..
>>>>>>>>>>     One could use PCSetUp_BJacobi_Multiproc() and get the 
>>>>>>>>>> blocks on the
>>>>>>>>>>     MPI ranks and then shrink each block down to a single GPU 
>>>>>>>>>> but this
>>>>>>>>>>     would be pretty inefficient, ideally one would go directly 
>>>>>>>>>> from the
>>>>>>>>>>     big MPI matrix on all the GPUs to the sub matrices on the 
>>>>>>>>>> subset of
>>>>>>>>>>     GPUs. But this may be a large coding project.
>>>>>>>>>> I don't understand these sentences. Why do you say "shrink"? 
>>>>>>>>>> In my mind, we just need to move each block (submatrix) living 
>>>>>>>>>> over multiple MPI ranks to one of them and solve directly 
>>>>>>>>>> there.  In other words, we keep blocks' size, no shrinking or 
>>>>>>>>>> expanding.
>>>>>>>>>> As mentioned before, cusparse does not provide LU 
>>>>>>>>>> factorization. So the LU factorization would be done on CPU, 
>>>>>>>>>> and the solve be done on GPU. I assume Chang wants to gain 
>>>>>>>>>> from the (potential) faster solve (instead of factorization) 
>>>>>>>>>> on GPU.
>>>>>>>>>>        Barry
>>>>>>>>>>     Since the matrices being factored and solved directly are 
>>>>>>>>>> relatively
>>>>>>>>>>     large it is possible that the cusparse code could be 
>>>>>>>>>> reasonably
>>>>>>>>>>     efficient (they are not the tiny problems one gets at the 
>>>>>>>>>> coarse
>>>>>>>>>>     level of multigrid). Of course, this is speculation, I don't
>>>>>>>>>>     actually know how much better the cusparse code would be 
>>>>>>>>>> on the
>>>>>>>>>>     direct solver than a good CPU direct sparse solver.
>>>>>>>>>>      > On Oct 13, 2021, at 9:32 PM, Chang Liu <cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>> wrote:
>>>>>>>>>>      >
>>>>>>>>>>      > Sorry I am not familiar with the details either. Can 
>>>>>>>>>> you please
>>>>>>>>>>     check the code in MatMumpsGatherNonzerosOnMaster in mumps.c?
>>>>>>>>>>      >
>>>>>>>>>>      > Chang
>>>>>>>>>>      >
>>>>>>>>>>      > On 10/13/21 9:24 PM, Junchao Zhang wrote:
>>>>>>>>>>      >> Hi Chang,
>>>>>>>>>>      >>   I did the work in mumps. It is easy for me to 
>>>>>>>>>> understand
>>>>>>>>>>     gathering matrix rows to one process.
>>>>>>>>>>      >>   But how to gather blocks (submatrices) to form a 
>>>>>>>>>> large block?     Can you draw a picture of that?
>>>>>>>>>>      >>   Thanks
>>>>>>>>>>      >> --Junchao Zhang
>>>>>>>>>>      >> On Wed, Oct 13, 2021 at 7:47 PM Chang Liu via petsc-users
>>>>>>>>>>     <petsc-users at mcs.anl.gov <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>>
>>>>>>>>>>     wrote:
>>>>>>>>>>      >>    Hi Barry,
>>>>>>>>>>      >>    I think mumps solver in petsc does support that. 
>>>>>>>>>> You can
>>>>>>>>>>     check the
>>>>>>>>>>      >>    documentation on "-mat_mumps_use_omp_threads" at
>>>>>>>>>>      >>
>>>>>>>>>>     
>>>>>>>>>> https://petsc.org/release/docs/manualpages/Mat/MATSOLVERMUMPS.html 
>>>>>>>>>>
>>>>>>>>>>     
>>>>>>>>>> <https://petsc.org/release/docs/manualpages/Mat/MATSOLVERMUMPS.html> 
>>>>>>>>>>
>>>>>>>>>>      >>       
>>>>>>>>>> <https://petsc.org/release/docs/manualpages/Mat/MATSOLVERMUMPS.html 
>>>>>>>>>>
>>>>>>>>>>     
>>>>>>>>>> <https://petsc.org/release/docs/manualpages/Mat/MATSOLVERMUMPS.html>> 
>>>>>>>>>>
>>>>>>>>>>      >>    and the code enclosed by #if
>>>>>>>>>>     defined(PETSC_HAVE_OPENMP_SUPPORT) in
>>>>>>>>>>      >>    functions MatMumpsSetUpDistRHSInfo and
>>>>>>>>>>      >>    MatMumpsGatherNonzerosOnMaster in
>>>>>>>>>>      >>    mumps.c
>>>>>>>>>>      >>    1. I understand it is ideal to do one MPI rank per 
>>>>>>>>>> GPU.
>>>>>>>>>>     However, I am
>>>>>>>>>>      >>    working on an existing code that was developed 
>>>>>>>>>> based on MPI
>>>>>>>>>>     and the the
>>>>>>>>>>      >>    # of mpi ranks is typically equal to # of cpu 
>>>>>>>>>> cores. We don't
>>>>>>>>>>     want to
>>>>>>>>>>      >>    change the whole structure of the code.
>>>>>>>>>>      >>    2. What you have suggested has been coded in 
>>>>>>>>>> mumps.c. See
>>>>>>>>>>     function
>>>>>>>>>>      >>    MatMumpsSetUpDistRHSInfo.
>>>>>>>>>>      >>    Regards,
>>>>>>>>>>      >>    Chang
>>>>>>>>>>      >>    On 10/13/21 7:53 PM, Barry Smith wrote:
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >> On Oct 13, 2021, at 3:50 PM, Chang Liu 
>>>>>>>>>> <cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>> wrote:
>>>>>>>>>>      >>     >>
>>>>>>>>>>      >>     >> Hi Barry,
>>>>>>>>>>      >>     >>
>>>>>>>>>>      >>     >> That is exactly what I want.
>>>>>>>>>>      >>     >>
>>>>>>>>>>      >>     >> Back to my original question, I am looking for 
>>>>>>>>>> an approach to
>>>>>>>>>>      >>    transfer
>>>>>>>>>>      >>     >> matrix
>>>>>>>>>>      >>     >> data from many MPI processes to "master" MPI
>>>>>>>>>>      >>     >> processes, each of which taking care of one 
>>>>>>>>>> GPU, and then
>>>>>>>>>>     upload
>>>>>>>>>>      >>    the data to GPU to
>>>>>>>>>>      >>     >> solve.
>>>>>>>>>>      >>     >> One can just grab some codes from mumps.c to
>>>>>>>>>>     aijcusparse.cu <http://aijcusparse.cu>
>>>>>>>>>>      >>    <http://aijcusparse.cu <http://aijcusparse.cu>>.
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >    mumps.c doesn't actually do that. It never 
>>>>>>>>>> needs to
>>>>>>>>>>     copy the
>>>>>>>>>>      >>    entire matrix to a single MPI rank.
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >    It would be possible to write such a code 
>>>>>>>>>> that you
>>>>>>>>>>     suggest but
>>>>>>>>>>      >>    it is not clear that it makes sense
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     > 1)  For normal PETSc GPU usage there is one GPU 
>>>>>>>>>> per MPI
>>>>>>>>>>     rank, so
>>>>>>>>>>      >>    while your one GPU per big domain is solving its 
>>>>>>>>>> systems the
>>>>>>>>>>     other
>>>>>>>>>>      >>    GPUs (with the other MPI ranks that share that 
>>>>>>>>>> domain) are doing
>>>>>>>>>>      >>    nothing.
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     > 2) For each triangular solve you would have to 
>>>>>>>>>> gather the
>>>>>>>>>>     right
>>>>>>>>>>      >>    hand side from the multiple ranks to the single GPU 
>>>>>>>>>> to pass it to
>>>>>>>>>>      >>    the GPU solver and then scatter the resulting 
>>>>>>>>>> solution back
>>>>>>>>>>     to all
>>>>>>>>>>      >>    of its subdomain ranks.
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >    What I was suggesting was assign an entire 
>>>>>>>>>> subdomain to a
>>>>>>>>>>      >>    single MPI rank, thus it does everything on one GPU 
>>>>>>>>>> and can
>>>>>>>>>>     use the
>>>>>>>>>>      >>    GPU solver directly. If all the major computations 
>>>>>>>>>> of a subdomain
>>>>>>>>>>      >>    can fit and be done on a single GPU then you would be
>>>>>>>>>>     utilizing all
>>>>>>>>>>      >>    the GPUs you are using effectively.
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >    Barry
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>     >>
>>>>>>>>>>      >>     >> Chang
>>>>>>>>>>      >>     >>
>>>>>>>>>>      >>     >> On 10/13/21 1:53 PM, Barry Smith wrote:
>>>>>>>>>>      >>     >>>    Chang,
>>>>>>>>>>      >>     >>>      You are correct there is no MPI + GPU direct
>>>>>>>>>>     solvers that
>>>>>>>>>>      >>    currently do the triangular solves with MPI + GPU 
>>>>>>>>>> parallelism
>>>>>>>>>>     that I
>>>>>>>>>>      >>    am aware of. You are limited that individual 
>>>>>>>>>> triangular solves be
>>>>>>>>>>      >>    done on a single GPU. I can only suggest making 
>>>>>>>>>> each subdomain as
>>>>>>>>>>      >>    big as possible to utilize each GPU as much as 
>>>>>>>>>> possible for the
>>>>>>>>>>      >>    direct triangular solves.
>>>>>>>>>>      >>     >>>     Barry
>>>>>>>>>>      >>     >>>> On Oct 13, 2021, at 12:16 PM, Chang Liu via 
>>>>>>>>>> petsc-users
>>>>>>>>>>      >>    <petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>>
>>>>>>>>>>     wrote:
>>>>>>>>>>      >>     >>>>
>>>>>>>>>>      >>     >>>> Hi Mark,
>>>>>>>>>>      >>     >>>>
>>>>>>>>>>      >>     >>>> '-mat_type aijcusparse' works with 
>>>>>>>>>> mpiaijcusparse with
>>>>>>>>>>     other
>>>>>>>>>>      >>    solvers, but with -pc_factor_mat_solver_type 
>>>>>>>>>> cusparse, it
>>>>>>>>>>     will give
>>>>>>>>>>      >>    an error.
>>>>>>>>>>      >>     >>>>
>>>>>>>>>>      >>     >>>> Yes what I want is to have mumps or superlu 
>>>>>>>>>> to do the
>>>>>>>>>>      >>    factorization, and then do the rest, including 
>>>>>>>>>> GMRES solver,
>>>>>>>>>>     on gpu.
>>>>>>>>>>      >>    Is that possible?
>>>>>>>>>>      >>     >>>>
>>>>>>>>>>      >>     >>>> I have tried to use aijcusparse with 
>>>>>>>>>> superlu_dist, it
>>>>>>>>>>     runs but
>>>>>>>>>>      >>    the iterative solver is still running on CPUs. I have
>>>>>>>>>>     contacted the
>>>>>>>>>>      >>    superlu group and they confirmed that is the case 
>>>>>>>>>> right now.
>>>>>>>>>>     But if
>>>>>>>>>>      >>    I set -pc_factor_mat_solver_type cusparse, it seems 
>>>>>>>>>> that the
>>>>>>>>>>      >>    iterative solver is running on GPU.
>>>>>>>>>>      >>     >>>>
>>>>>>>>>>      >>     >>>> Chang
>>>>>>>>>>      >>     >>>>
>>>>>>>>>>      >>     >>>> On 10/13/21 12:03 PM, Mark Adams wrote:
>>>>>>>>>>      >>     >>>>> On Wed, Oct 13, 2021 at 11:10 AM Chang Liu
>>>>>>>>>>     <cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>> wrote:
>>>>>>>>>>      >>     >>>>>     Thank you Junchao for explaining this. I 
>>>>>>>>>> guess in
>>>>>>>>>>     my case
>>>>>>>>>>      >>    the code is
>>>>>>>>>>      >>     >>>>>     just calling a seq solver like superlu 
>>>>>>>>>> to do
>>>>>>>>>>      >>    factorization on GPUs.
>>>>>>>>>>      >>     >>>>>     My idea is that I want to have a 
>>>>>>>>>> traditional MPI
>>>>>>>>>>     code to
>>>>>>>>>>      >>    utilize GPUs
>>>>>>>>>>      >>     >>>>>     with cusparse. Right now cusparse does 
>>>>>>>>>> not support
>>>>>>>>>>     mpiaij
>>>>>>>>>>      >>    matrix, Sure it does: '-mat_type aijcusparse' will 
>>>>>>>>>> give you an
>>>>>>>>>>      >>    mpiaijcusparse matrix with > 1 processes.
>>>>>>>>>>      >>     >>>>> (-mat_type mpiaijcusparse might also work 
>>>>>>>>>> with >1 proc).
>>>>>>>>>>      >>     >>>>> However, I see in grepping the repo that all 
>>>>>>>>>> the mumps and
>>>>>>>>>>      >>    superlu tests use aij or sell matrix type.
>>>>>>>>>>      >>     >>>>> MUMPS and SuperLU provide their own solves, 
>>>>>>>>>> I assume
>>>>>>>>>>     .... but
>>>>>>>>>>      >>    you might want to do other matrix operations on the 
>>>>>>>>>> GPU. Is
>>>>>>>>>>     that the
>>>>>>>>>>      >>    issue?
>>>>>>>>>>      >>     >>>>> Did you try -mat_type aijcusparse with MUMPS 
>>>>>>>>>> and/or
>>>>>>>>>>     SuperLU
>>>>>>>>>>      >>    have a problem? (no test with it so it probably 
>>>>>>>>>> does not work)
>>>>>>>>>>      >>     >>>>> Thanks,
>>>>>>>>>>      >>     >>>>> Mark
>>>>>>>>>>      >>     >>>>>     so I
>>>>>>>>>>      >>     >>>>>     want the code to have a mpiaij matrix 
>>>>>>>>>> when adding
>>>>>>>>>>     all the
>>>>>>>>>>      >>    matrix terms,
>>>>>>>>>>      >>     >>>>>     and then transform the matrix to seqaij 
>>>>>>>>>> when doing the
>>>>>>>>>>      >>    factorization
>>>>>>>>>>      >>     >>>>>     and
>>>>>>>>>>      >>     >>>>>     solve. This involves sending the data to 
>>>>>>>>>> the master
>>>>>>>>>>      >>    process, and I
>>>>>>>>>>      >>     >>>>>     think
>>>>>>>>>>      >>     >>>>>     the petsc mumps solver have something 
>>>>>>>>>> similar already.
>>>>>>>>>>      >>     >>>>>     Chang
>>>>>>>>>>      >>     >>>>>     On 10/13/21 10:18 AM, Junchao Zhang wrote:
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      > On Tue, Oct 12, 2021 at 1:07 PM Mark 
>>>>>>>>>> Adams
>>>>>>>>>>      >>    <mfadams at lbl.gov <mailto:mfadams at lbl.gov>
>>>>>>>>>>     <mailto:mfadams at lbl.gov <mailto:mfadams at lbl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:mfadams at lbl.gov 
>>>>>>>>>> <mailto:mfadams at lbl.gov>
>>>>>>>>>>     <mailto:mfadams at lbl.gov <mailto:mfadams at lbl.gov>>>
>>>>>>>>>>      >>     >>>>>      > <mailto:mfadams at lbl.gov
>>>>>>>>>>     <mailto:mfadams at lbl.gov> <mailto:mfadams at lbl.gov
>>>>>>>>>>     <mailto:mfadams at lbl.gov>>
>>>>>>>>>>      >>    <mailto:mfadams at lbl.gov <mailto:mfadams at lbl.gov>
>>>>>>>>>>     <mailto:mfadams at lbl.gov <mailto:mfadams at lbl.gov>>>>> wrote:
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >     On Tue, Oct 12, 2021 at 1:45 PM 
>>>>>>>>>> Chang Liu
>>>>>>>>>>      >>    <cliu at pppl.gov <mailto:cliu at pppl.gov> 
>>>>>>>>>> <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>      >     <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov> <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>> wrote:
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >         Hi Mark,
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >         The option I use is like
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >         -pc_type bjacobi 
>>>>>>>>>> -pc_bjacobi_blocks 16
>>>>>>>>>>      >>    -ksp_type fgmres
>>>>>>>>>>      >>     >>>>>     -mat_type
>>>>>>>>>>      >>     >>>>>      >         aijcusparse 
>>>>>>>>>> *-sub_pc_factor_mat_solver_type
>>>>>>>>>>      >>    cusparse
>>>>>>>>>>      >>     >>>>>     *-sub_ksp_type
>>>>>>>>>>      >>     >>>>>      >         preonly *-sub_pc_type lu* 
>>>>>>>>>> -ksp_max_it 2000
>>>>>>>>>>      >>    -ksp_rtol 1.e-300
>>>>>>>>>>      >>     >>>>>      >         -ksp_atol 1.e-300
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >     Note, If you use -log_view the 
>>>>>>>>>> last column
>>>>>>>>>>     (rows
>>>>>>>>>>      >>    are the
>>>>>>>>>>      >>     >>>>>     method like
>>>>>>>>>>      >>     >>>>>      >     MatFactorNumeric) has the percent 
>>>>>>>>>> of work
>>>>>>>>>>     in the GPU.
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >     Junchao: *This* implies that we 
>>>>>>>>>> have a
>>>>>>>>>>     cuSparse LU
>>>>>>>>>>      >>     >>>>>     factorization. Is
>>>>>>>>>>      >>     >>>>>      >     that correct? (I don't think we do)
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      > No, we don't have cuSparse LU 
>>>>>>>>>> factorization.     If you check
>>>>>>>>>>      >>     >>>>>      > 
>>>>>>>>>> MatLUFactorSymbolic_SeqAIJCUSPARSE(),you will
>>>>>>>>>>     find it
>>>>>>>>>>      >>    calls
>>>>>>>>>>      >>     >>>>>      > MatLUFactorSymbolic_SeqAIJ() instead.
>>>>>>>>>>      >>     >>>>>      > So I don't understand Chang's idea. 
>>>>>>>>>> Do you want to
>>>>>>>>>>      >>    make bigger
>>>>>>>>>>      >>     >>>>>     blocks?
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >         I think this one do both 
>>>>>>>>>> factorization and
>>>>>>>>>>      >>    solve on gpu.
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >         You can check the
>>>>>>>>>>     runex72_aijcusparse.sh file
>>>>>>>>>>      >>    in petsc
>>>>>>>>>>      >>     >>>>>     install
>>>>>>>>>>      >>     >>>>>      >         directory, and try it your 
>>>>>>>>>> self (this
>>>>>>>>>>     is only lu
>>>>>>>>>>      >>     >>>>>     factorization
>>>>>>>>>>      >>     >>>>>      >         without
>>>>>>>>>>      >>     >>>>>      >         iterative solve).
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >         Chang
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >         On 10/12/21 1:17 PM, Mark 
>>>>>>>>>> Adams wrote:
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          > On Tue, Oct 12, 2021 at 
>>>>>>>>>> 11:19 AM
>>>>>>>>>>     Chang Liu
>>>>>>>>>>      >>     >>>>>     <cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>      >         <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov> <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>
>>>>>>>>>>      >>     >>>>>      >          > <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov> 
>>>>>>>>>> <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>>> wrote:
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >     Hi Junchao,
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >     No I only needs it to 
>>>>>>>>>> be transferred
>>>>>>>>>>      >>    within a
>>>>>>>>>>      >>     >>>>>     node. I use
>>>>>>>>>>      >>     >>>>>      >         block-Jacobi
>>>>>>>>>>      >>     >>>>>      >          >     method and GMRES to 
>>>>>>>>>> solve the sparse
>>>>>>>>>>      >>    matrix, so each
>>>>>>>>>>      >>     >>>>>      >         direct solver will
>>>>>>>>>>      >>     >>>>>      >          >     take care of a 
>>>>>>>>>> sub-block of the
>>>>>>>>>>     whole
>>>>>>>>>>      >>    matrix. In this
>>>>>>>>>>      >>     >>>>>      >         way, I can use
>>>>>>>>>>      >>     >>>>>      >          >     one
>>>>>>>>>>      >>     >>>>>      >          >     GPU to solve one 
>>>>>>>>>> sub-block, which is
>>>>>>>>>>      >>    stored within
>>>>>>>>>>      >>     >>>>>     one node.
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >     It was stated in the
>>>>>>>>>>     documentation that
>>>>>>>>>>      >>    cusparse
>>>>>>>>>>      >>     >>>>>     solver
>>>>>>>>>>      >>     >>>>>      >         is slow.
>>>>>>>>>>      >>     >>>>>      >          >     However, in my test using
>>>>>>>>>>     ex72.c, the
>>>>>>>>>>      >>    cusparse
>>>>>>>>>>      >>     >>>>>     solver is
>>>>>>>>>>      >>     >>>>>      >         faster than
>>>>>>>>>>      >>     >>>>>      >          >     mumps or superlu_dist 
>>>>>>>>>> on CPUs.
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          > Are we talking about the
>>>>>>>>>>     factorization, the
>>>>>>>>>>      >>    solve, or
>>>>>>>>>>      >>     >>>>>     both?
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          > We do not have an 
>>>>>>>>>> interface to
>>>>>>>>>>     cuSparse's LU
>>>>>>>>>>      >>     >>>>>     factorization (I
>>>>>>>>>>      >>     >>>>>      >         just
>>>>>>>>>>      >>     >>>>>      >          > learned that it exists a 
>>>>>>>>>> few weeks ago).
>>>>>>>>>>      >>     >>>>>      >          > Perhaps your fast 
>>>>>>>>>> "cusparse solver" is
>>>>>>>>>>      >>    '-pc_type lu
>>>>>>>>>>      >>     >>>>>     -mat_type
>>>>>>>>>>      >>     >>>>>      >          > aijcusparse' ? This would 
>>>>>>>>>> be the CPU
>>>>>>>>>>      >>    factorization,
>>>>>>>>>>      >>     >>>>>     which is the
>>>>>>>>>>      >>     >>>>>      >          > dominant cost.
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >     Chang
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >     On 10/12/21 10:24 AM, 
>>>>>>>>>> Junchao
>>>>>>>>>>     Zhang wrote:
>>>>>>>>>>      >>     >>>>>      >          >      > Hi, Chang,
>>>>>>>>>>      >>     >>>>>      >          >      >     For the mumps 
>>>>>>>>>> solver, we
>>>>>>>>>>     usually
>>>>>>>>>>      >>    transfers
>>>>>>>>>>      >>     >>>>>     matrix
>>>>>>>>>>      >>     >>>>>      >         and vector
>>>>>>>>>>      >>     >>>>>      >          >     data
>>>>>>>>>>      >>     >>>>>      >          >      > within a compute 
>>>>>>>>>> node.  For
>>>>>>>>>>     the idea you
>>>>>>>>>>      >>     >>>>>     propose, it
>>>>>>>>>>      >>     >>>>>      >         looks like
>>>>>>>>>>      >>     >>>>>      >          >     we need
>>>>>>>>>>      >>     >>>>>      >          >      > to gather data within
>>>>>>>>>>      >>    MPI_COMM_WORLD, right?
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >      >     Mark, I 
>>>>>>>>>> remember you said
>>>>>>>>>>      >>    cusparse solve is
>>>>>>>>>>      >>     >>>>>     slow
>>>>>>>>>>      >>     >>>>>      >         and you would
>>>>>>>>>>      >>     >>>>>      >          >      > rather do it on 
>>>>>>>>>> CPU. Is it right?
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >      > --Junchao Zhang
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >      > On Mon, Oct 11, 
>>>>>>>>>> 2021 at 10:25 PM
>>>>>>>>>>      >>    Chang Liu via
>>>>>>>>>>      >>     >>>>>     petsc-users
>>>>>>>>>>      >>     >>>>>      >          >      > 
>>>>>>>>>> <petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>>>
>>>>>>>>>>      >>     >>>>>      >         <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>>>> 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>>>
>>>>>>>>>>      >>     >>>>>      >         <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>>>>>
>>>>>>>>>>      >>     >>>>>      >          >     
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>>>
>>>>>>>>>>      >>     >>>>>      >         <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>>>> 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>>>
>>>>>>>>>>      >>     >>>>>      >         <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov 
>>>>>>>>>> <mailto:petsc-users at mcs.anl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>
>>>>>>>>>>      >>    <mailto:petsc-users at mcs.anl.gov
>>>>>>>>>>     <mailto:petsc-users at mcs.anl.gov>>>>>>>
>>>>>>>>>>      >>     >>>>>      >          >     wrote:
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >      >     Hi,
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >      >     Currently, it 
>>>>>>>>>> is possible
>>>>>>>>>>     to use
>>>>>>>>>>      >>    mumps
>>>>>>>>>>      >>     >>>>>     solver in
>>>>>>>>>>      >>     >>>>>      >         PETSC with
>>>>>>>>>>      >>     >>>>>      >          >      >     
>>>>>>>>>> -mat_mumps_use_omp_threads
>>>>>>>>>>      >>    option, so that
>>>>>>>>>>      >>     >>>>>      >         multiple MPI
>>>>>>>>>>      >>     >>>>>      >          >     processes will
>>>>>>>>>>      >>     >>>>>      >          >      >     transfer the 
>>>>>>>>>> matrix and
>>>>>>>>>>     rhs data
>>>>>>>>>>      >>    to the master
>>>>>>>>>>      >>     >>>>>      >         rank, and then
>>>>>>>>>>      >>     >>>>>      >          >     master
>>>>>>>>>>      >>     >>>>>      >          >      >     rank will call 
>>>>>>>>>> mumps with
>>>>>>>>>>     OpenMP
>>>>>>>>>>      >>    to solve
>>>>>>>>>>      >>     >>>>>     the matrix.
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >      >     I wonder if 
>>>>>>>>>> someone can
>>>>>>>>>>     develop
>>>>>>>>>>      >>    similar
>>>>>>>>>>      >>     >>>>>     option for
>>>>>>>>>>      >>     >>>>>      >         cusparse
>>>>>>>>>>      >>     >>>>>      >          >     solver.
>>>>>>>>>>      >>     >>>>>      >          >      >     Right now, this 
>>>>>>>>>> solver
>>>>>>>>>>     does not
>>>>>>>>>>      >>    work with
>>>>>>>>>>      >>     >>>>>      >         mpiaijcusparse. I
>>>>>>>>>>      >>     >>>>>      >          >     think a
>>>>>>>>>>      >>     >>>>>      >          >      >     possible 
>>>>>>>>>> workaround is to
>>>>>>>>>>      >>    transfer all the
>>>>>>>>>>      >>     >>>>>     matrix
>>>>>>>>>>      >>     >>>>>      >         data to one MPI
>>>>>>>>>>      >>     >>>>>      >          >      >     process, and 
>>>>>>>>>> then upload the
>>>>>>>>>>      >>    data to GPU to
>>>>>>>>>>      >>     >>>>>     solve.
>>>>>>>>>>      >>     >>>>>      >         In this
>>>>>>>>>>      >>     >>>>>      >          >     way, one can
>>>>>>>>>>      >>     >>>>>      >          >      >     use cusparse 
>>>>>>>>>> solver for a MPI
>>>>>>>>>>      >>    program.
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >      >     Chang
>>>>>>>>>>      >>     >>>>>      >          >      >     --
>>>>>>>>>>      >>     >>>>>      >          >      >     Chang Liu
>>>>>>>>>>      >>     >>>>>      >          >      >     Staff Research 
>>>>>>>>>> Physicist
>>>>>>>>>>      >>     >>>>>      >          >      >     +1 609 243 3438
>>>>>>>>>>      >>     >>>>>      >          >      > cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov> <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>
>>>>>>>>>>      >>     >>>>>      >         <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov> <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>>
>>>>>>>>>>      >>     >>>>>      >         <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov> <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>
>>>>>>>>>>      >>     >>>>>      >          >     <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov> 
>>>>>>>>>> <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>>>
>>>>>>>>>>      >>     >>>>>      >          >      >     Princeton 
>>>>>>>>>> Plasma Physics
>>>>>>>>>>     Laboratory
>>>>>>>>>>      >>     >>>>>      >          >      >     100 Stellarator 
>>>>>>>>>> Rd,
>>>>>>>>>>     Princeton NJ
>>>>>>>>>>      >>    08540, USA
>>>>>>>>>>      >>     >>>>>      >          >      >
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >          >     --
>>>>>>>>>>      >>     >>>>>      >          >     Chang Liu
>>>>>>>>>>      >>     >>>>>      >          >     Staff Research Physicist
>>>>>>>>>>      >>     >>>>>      >          >     +1 609 243 3438
>>>>>>>>>>      >>     >>>>>      >          > cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>      >         <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov> <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>>
>>>>>>>>>>      >>     >>>>>      >          >     Princeton Plasma 
>>>>>>>>>> Physics Laboratory
>>>>>>>>>>      >>     >>>>>      >          >     100 Stellarator Rd, 
>>>>>>>>>> Princeton NJ
>>>>>>>>>>     08540, USA
>>>>>>>>>>      >>     >>>>>      >          >
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>      >         --
>>>>>>>>>>      >>     >>>>>      >         Chang Liu
>>>>>>>>>>      >>     >>>>>      >         Staff Research Physicist
>>>>>>>>>>      >>     >>>>>      >         +1 609 243 3438
>>>>>>>>>>      >>     >>>>>      > cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>> 
>>>>>>>>>> <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>     >>>>>     <mailto:cliu at pppl.gov 
>>>>>>>>>> <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>>
>>>>>>>>>>      >>     >>>>>      >         Princeton Plasma Physics 
>>>>>>>>>> Laboratory
>>>>>>>>>>      >>     >>>>>      >         100 Stellarator Rd, Princeton 
>>>>>>>>>> NJ 08540, USA
>>>>>>>>>>      >>     >>>>>      >
>>>>>>>>>>      >>     >>>>>     --     Chang Liu
>>>>>>>>>>      >>     >>>>>     Staff Research Physicist
>>>>>>>>>>      >>     >>>>>     +1 609 243 3438
>>>>>>>>>>      >>     >>>>> cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>> 
>>>>>>>>>> <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>
>>>>>>>>>>      >>    <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>>
>>>>>>>>>>      >>     >>>>>     Princeton Plasma Physics Laboratory
>>>>>>>>>>      >>     >>>>>     100 Stellarator Rd, Princeton NJ 08540, USA
>>>>>>>>>>      >>     >>>>
>>>>>>>>>>      >>     >>>> --
>>>>>>>>>>      >>     >>>> Chang Liu
>>>>>>>>>>      >>     >>>> Staff Research Physicist
>>>>>>>>>>      >>     >>>> +1 609 243 3438
>>>>>>>>>>      >>     >>>> cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>     >>>> Princeton Plasma Physics Laboratory
>>>>>>>>>>      >>     >>>> 100 Stellarator Rd, Princeton NJ 08540, USA
>>>>>>>>>>      >>     >>
>>>>>>>>>>      >>     >> --
>>>>>>>>>>      >>     >> Chang Liu
>>>>>>>>>>      >>     >> Staff Research Physicist
>>>>>>>>>>      >>     >> +1 609 243 3438
>>>>>>>>>>      >>     >> cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>     <mailto:cliu at pppl.gov <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>     >> Princeton Plasma Physics Laboratory
>>>>>>>>>>      >>     >> 100 Stellarator Rd, Princeton NJ 08540, USA
>>>>>>>>>>      >>     >
>>>>>>>>>>      >>    --     Chang Liu
>>>>>>>>>>      >>    Staff Research Physicist
>>>>>>>>>>      >>    +1 609 243 3438
>>>>>>>>>>      >> cliu at pppl.gov <mailto:cliu at pppl.gov> 
>>>>>>>>>> <mailto:cliu at pppl.gov
>>>>>>>>>>     <mailto:cliu at pppl.gov>>
>>>>>>>>>>      >>    Princeton Plasma Physics Laboratory
>>>>>>>>>>      >>    100 Stellarator Rd, Princeton NJ 08540, USA
>>>>>>>>>>      >
>>>>>>>>>>      > --
>>>>>>>>>>      > Chang Liu
>>>>>>>>>>      > Staff Research Physicist
>>>>>>>>>>      > +1 609 243 3438
>>>>>>>>>>      > cliu at pppl.gov <mailto:cliu at pppl.gov>
>>>>>>>>>>      > Princeton Plasma Physics Laboratory
>>>>>>>>>>      > 100 Stellarator Rd, Princeton NJ 08540, USA
>>>>>>>>>
>>>>>>>>> -- 
>>>>>>>>> Chang Liu
>>>>>>>>> Staff Research Physicist
>>>>>>>>> +1 609 243 3438
>>>>>>>>> cliu at pppl.gov
>>>>>>>>> Princeton Plasma Physics Laboratory
>>>>>>>>> 100 Stellarator Rd, Princeton NJ 08540, USA
>>>>>>>
>>>>>>> -- 
>>>>>>> Chang Liu
>>>>>>> Staff Research Physicist
>>>>>>> +1 609 243 3438
>>>>>>> cliu at pppl.gov
>>>>>>> Princeton Plasma Physics Laboratory
>>>>>>> 100 Stellarator Rd, Princeton NJ 08540, USA
>>>>>
>>>>> -- 
>>>>> Chang Liu
>>>>> Staff Research Physicist
>>>>> +1 609 243 3438
>>>>> cliu at pppl.gov
>>>>> Princeton Plasma Physics Laboratory
>>>>> 100 Stellarator Rd, Princeton NJ 08540, USA
>>>
>>> -- 
>>> Chang Liu
>>> Staff Research Physicist
>>> +1 609 243 3438
>>> cliu at pppl.gov
>>> Princeton Plasma Physics Laboratory
>>> 100 Stellarator Rd, Princeton NJ 08540, USA
>>
> 

-- 
Chang Liu
Staff Research Physicist
+1 609 243 3438
cliu at pppl.gov
Princeton Plasma Physics Laboratory
100 Stellarator Rd, Princeton NJ 08540, USA


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