Thread-parallelize src term addition Euler Gravity

[DanielDoehring]

It ain't much, but it is honest work something.

2 Threads, eulergravity_sedov_blast_wave.jl with present implementation:

 ────────────────────────────────────────────────────────────────────────────────────────────────────
 Simulation running 'CompressibleEulerEquations2D' with DGSEM(polydeg=3)
────────────────────────────────────────────────────────────────────────────────────────────────────
 #timesteps:                586                run time:       2.94421216e+01 s
 Δt:             2.36742707e-03                └── GC time:    5.35440100e-02 s (0.182%)
 sim. time:      1.00000000e+00 (100.000%)     time/DOF/rhs!:  1.34115176e-07 s
                                               PID:            2.35086078e-07 s
 #DOFs per field:         59008                alloc'd memory:        427.173 MiB
 #elements:                3688
 ├── level 8:              2800
 ├── level 7:               580
 ├── level 6:               144
 ├── level 5:                92
 ├── level 4:                44
 ├── level 3:                24
 └── level 2:                 4

 Variable:       rho              rho_v1           rho_v2           rho_e         
 L2 error:       2.82838970e-01   9.56723845e-02   9.56723846e-02   5.07100358e-01
 Linf error:     3.88847701e+00   1.75078666e+00   1.75078668e+00   2.01765025e+01
 ∑∂S/∂U ⋅ Uₜ :  -6.27383203e-02
 ∑e_total    :   1.57946744e-02
 ∑e_kinetic  :   3.27940639e-03
 ∑e_internal :   1.25152680e-02
────────────────────────────────────────────────────────────────────────────────────────────────────

────────────────────────────────────────────────────────────────────────────────────────────────────
Trixi.jl simulation finished.  Final time: 1.0  Time steps: 586 (accepted), 586 (total)
────────────────────────────────────────────────────────────────────────────────────────────────────

 ───────────────────────────────────────────────────────────────────────────────────────
               Trixi.jl                        Time                    Allocations      
                                      ───────────────────────   ────────────────────────
           Tot / % measured:               29.7s /  93.3%           4.46GiB /  99.6%    

 Section                      ncalls     time    %tot     avg     alloc    %tot      avg
 ───────────────────────────────────────────────────────────────────────────────────────
 gravity solver                2.93k    10.6s   38.3%  3.62ms   65.3MiB    1.4%  22.8KiB
   rhs!                        14.7k    7.99s   28.8%   545μs   61.3MiB    1.3%  4.28KiB
     volume integral           14.7k    3.10s   11.2%   212μs   4.25MiB    0.1%     304B
     mortar flux               14.7k    1.35s    4.9%  91.8μs   6.26MiB    0.1%     448B
     surface integral          14.7k    810ms    2.9%  55.3μs   4.03MiB    0.1%     288B
     interface flux            14.7k    803ms    2.9%  54.8μs   4.70MiB    0.1%     336B
     source terms              14.7k    612ms    2.2%  41.8μs   4.03MiB    0.1%     288B
     prolong2interfaces        14.7k    394ms    1.4%  26.9μs   4.25MiB    0.1%     304B
     prolong2mortars           14.7k    315ms    1.1%  21.5μs   4.25MiB    0.1%     304B
     Jacobian                  14.7k    272ms    1.0%  18.5μs   3.35MiB    0.1%     240B
     reset ∂u/∂t               14.7k    231ms    0.8%  15.8μs     0.00B    0.0%    0.00B
     boundary flux             14.7k   71.2ms    0.3%  4.86μs   22.4MiB    0.5%  1.56KiB
     ~rhs!~                    14.7k   21.0ms    0.1%  1.43μs   9.33KiB    0.0%    0.65B
     prolong2boundaries        14.7k   12.5ms    0.0%   854ns   3.80MiB    0.1%     272B
   ~gravity solver~            2.93k    1.46s    5.3%   498μs   3.98MiB    0.1%  1.39KiB
   Runge-Kutta step            14.7k    1.15s    4.2%  78.5μs     0.00B    0.0%    0.00B
   calculate dt                2.93k   3.12ms    0.0%  1.06μs     0.00B    0.0%    0.00B
 AMR                             585    8.75s   31.6%  15.0ms   4.33GiB   97.4%  7.57MiB
   coarsen                       585    4.41s   15.9%  7.54ms   2.56GiB   57.7%  4.48MiB
     mesh                        585    2.98s   10.7%  5.09ms   5.00MiB    0.1%  8.76KiB
     solver                      585    668ms    2.4%  1.14ms   0.98GiB   22.1%  1.72MiB
     passive solver              585    538ms    1.9%   920μs    775MiB   17.0%  1.33MiB
     ~coarsen~                   585    224ms    0.8%   383μs    836MiB   18.4%  1.43MiB
   refine                        585    4.24s   15.3%  7.25ms   1.70GiB   38.2%  2.97MiB
     mesh                        507    3.08s   11.1%  6.07ms   7.95MiB    0.2%  16.1KiB
       refine_unbalanced!        507    2.99s   10.8%  5.89ms    331KiB    0.0%     668B
       rebalance!                629   80.6ms    0.3%   128μs   1.95MiB    0.0%  3.18KiB
       ~mesh~                    507   9.18ms    0.0%  18.1μs   5.68MiB    0.1%  11.5KiB
     solver                      507    620ms    2.2%  1.22ms   0.95GiB   21.4%  1.92MiB
     passive solver              507    539ms    1.9%  1.06ms    752MiB   16.5%  1.48MiB
     ~refine~                    585   3.11ms    0.0%  5.32μs    782KiB    0.0%  1.34KiB
   indicator                     585   78.7ms    0.3%   134μs   31.0MiB    0.7%  54.3KiB
   ~AMR~                         585   26.7ms    0.1%  45.6μs   40.3MiB    0.9%  70.5KiB
 Euler solver                  2.93k    7.96s   28.7%  2.72ms   17.0MiB    0.4%  5.93KiB
   rhs!                        2.93k    7.96s   28.7%  2.72ms   17.0MiB    0.4%  5.92KiB
     volume integral           2.93k    6.72s   24.3%  2.29ms   4.20MiB    0.1%  1.47KiB
       blended DG-FV           2.93k    5.38s   19.4%  1.84ms   1.25MiB    0.0%     448B
       pure DG                 2.93k    919ms    3.3%   314μs   1.25MiB    0.0%     448B
       blending factors        2.93k    361ms    1.3%   123μs   1.65MiB    0.0%     591B
       ~volume integral~       2.93k   62.5ms    0.2%  21.3μs   48.6KiB    0.0%    17.0B
     interface flux            2.93k    375ms    1.4%   128μs   1.12MiB    0.0%     400B
     mortar flux               2.93k    254ms    0.9%  86.5μs   1.61MiB    0.0%     576B
     surface integral          2.93k    197ms    0.7%  67.3μs    962KiB    0.0%     336B
     prolong2interfaces        2.93k    133ms    0.5%  45.5μs   1.03MiB    0.0%     368B
     Jacobian                  2.93k   87.6ms    0.3%  29.9μs    870KiB    0.0%     304B
     reset ∂u/∂t               2.93k   82.5ms    0.3%  28.1μs     0.00B    0.0%    0.00B
     prolong2mortars           2.93k   82.0ms    0.3%  28.0μs   1.25MiB    0.0%     448B
     boundary flux             2.93k   11.6ms    0.0%  3.94μs   5.01MiB    0.1%  1.75KiB
     ~rhs!~                    2.93k   6.89ms    0.0%  2.35μs   9.33KiB    0.0%    3.26B
     prolong2boundaries        2.93k   4.08ms    0.0%  1.39μs    962KiB    0.0%     336B
     source terms              2.93k   77.5μs    0.0%  26.5ns     0.00B    0.0%    0.00B
   ~Euler solver~              2.93k   1.19ms    0.0%   405ns      752B    0.0%    0.26B
 analyze solution                  7    250ms    0.9%  35.6ms   14.8MiB    0.3%  2.11MiB
 calculate dt                    587    120ms    0.4%   205μs     0.00B    0.0%    0.00B
 initial condition AMR             1   14.7ms    0.1%  14.7ms   21.4MiB    0.5%  21.4MiB
   AMR                             7   14.1ms    0.1%  2.02ms   21.4MiB    0.5%  3.06MiB
     refine                        7   13.3ms    0.0%  1.90ms   16.4MiB    0.4%  2.35MiB
       mesh                        6   10.0ms    0.0%  1.67ms    126KiB    0.0%  21.0KiB
         refine_unbalanced!        6   6.67ms    0.0%  1.11ms   4.73KiB    0.0%     808B
         rebalance!               14   3.29ms    0.0%   235μs   54.8KiB    0.0%  3.91KiB
         ~mesh~                    6   42.5μs    0.0%  7.08μs   66.5KiB    0.0%  11.1KiB
       solver                      6   1.65ms    0.0%   276μs   7.94MiB    0.2%  1.32MiB
       passive solver              6   1.62ms    0.0%   270μs   8.37MiB    0.2%  1.39MiB
       ~refine~                    7   16.1μs    0.0%  2.30μs   14.7KiB    0.0%  2.10KiB
     ~AMR~                         7    501μs    0.0%  71.6μs   4.86MiB    0.1%   710KiB
     indicator                     7    323μs    0.0%  46.1μs    113KiB    0.0%  16.2KiB
     coarsen                       7   1.03μs    0.0%   147ns      448B    0.0%    64.0B
   ~initial condition AMR~         1    551μs    0.0%   551μs   4.77KiB    0.0%  4.77KiB
 ───────────────────────────────────────────────────────────────────────────────────────

With thread-parallelization of source term addition:

────────────────────────────────────────────────────────────────────────────────────────────────────
 Simulation running 'CompressibleEulerEquations2D' with DGSEM(polydeg=3)
────────────────────────────────────────────────────────────────────────────────────────────────────
 #timesteps:                586                run time:       2.83292507e+01 s
 Δt:             2.36742707e-03                └── GC time:    5.74641740e-02 s (0.203%)
 sim. time:      1.00000000e+00 (100.000%)     time/DOF/rhs!:  1.24045952e-07 s
                                               PID:            2.26951851e-07 s
 #DOFs per field:         59008                alloc'd memory:        514.209 MiB
 #elements:                3688
 ├── level 8:              2800
 ├── level 7:               580
 ├── level 6:               144
 ├── level 5:                92
 ├── level 4:                44
 ├── level 3:                24
 └── level 2:                 4

 Variable:       rho              rho_v1           rho_v2           rho_e         
 L2 error:       2.82838970e-01   9.56723845e-02   9.56723846e-02   5.07100358e-01
 Linf error:     3.88847701e+00   1.75078666e+00   1.75078668e+00   2.01765025e+01
 ∑∂S/∂U ⋅ Uₜ :  -6.27383203e-02
 ∑e_total    :   1.57946744e-02
 ∑e_kinetic  :   3.27940639e-03
 ∑e_internal :   1.25152680e-02
────────────────────────────────────────────────────────────────────────────────────────────────────

────────────────────────────────────────────────────────────────────────────────────────────────────
Trixi.jl simulation finished.  Final time: 1.0  Time steps: 586 (accepted), 586 (total)
────────────────────────────────────────────────────────────────────────────────────────────────────

 ───────────────────────────────────────────────────────────────────────────────────────
               Trixi.jl                        Time                    Allocations      
                                      ───────────────────────   ────────────────────────
           Tot / % measured:               28.7s /  94.5%           4.47GiB /  99.4%    

 Section                      ncalls     time    %tot     avg     alloc    %tot      avg
 ───────────────────────────────────────────────────────────────────────────────────────
 gravity solver                2.93k    9.82s   36.3%  3.35ms   65.3MiB    1.4%  22.8KiB
   rhs!                        14.7k    7.69s   28.4%   525μs   61.3MiB    1.3%  4.28KiB
     volume integral           14.7k    3.12s   11.5%   213μs   4.25MiB    0.1%     304B
     mortar flux               14.7k    1.11s    4.1%  75.6μs   6.26MiB    0.1%     448B
     interface flux            14.7k    806ms    3.0%  55.0μs   4.70MiB    0.1%     336B
     surface integral          14.7k    751ms    2.8%  51.3μs   4.03MiB    0.1%     288B
     source terms              14.7k    623ms    2.3%  42.5μs   4.03MiB    0.1%     288B
     prolong2interfaces        14.7k    397ms    1.5%  27.1μs   4.25MiB    0.1%     304B
     prolong2mortars           14.7k    321ms    1.2%  21.9μs   4.25MiB    0.1%     304B
     Jacobian                  14.7k    269ms    1.0%  18.3μs   3.35MiB    0.1%     240B
     reset ∂u/∂t               14.7k    232ms    0.9%  15.8μs     0.00B    0.0%    0.00B
     boundary flux             14.7k   30.5ms    0.1%  2.08μs   22.4MiB    0.5%  1.56KiB
     ~rhs!~                    14.7k   22.5ms    0.1%  1.53μs   9.33KiB    0.0%    0.65B
     prolong2boundaries        14.7k   12.8ms    0.0%   870ns   3.80MiB    0.1%     272B
   Runge-Kutta step            14.7k    1.18s    4.4%  80.4μs     0.00B    0.0%    0.00B
   ~gravity solver~            2.93k    946ms    3.5%   323μs   3.98MiB    0.1%  1.39KiB
   calculate dt                2.93k   3.07ms    0.0%  1.05μs     0.00B    0.0%    0.00B
 AMR                             585    8.79s   32.4%  15.0ms   4.33GiB   97.4%  7.57MiB
   coarsen                       585    4.43s   16.4%  7.58ms   2.56GiB   57.7%  4.48MiB
     mesh                        585    3.01s   11.1%  5.15ms   5.00MiB    0.1%  8.76KiB
     solver                      585    611ms    2.3%  1.04ms   0.98GiB   22.1%  1.72MiB
     passive solver              585    606ms    2.2%  1.04ms    775MiB   17.0%  1.33MiB
     ~coarsen~                   585    201ms    0.7%   343μs    836MiB   18.4%  1.43MiB
   refine                        585    4.24s   15.6%  7.25ms   1.70GiB   38.2%  2.97MiB
     mesh                        507    3.15s   11.6%  6.22ms   7.95MiB    0.2%  16.1KiB
       refine_unbalanced!        507    3.06s   11.3%  6.04ms    331KiB    0.0%     668B
       rebalance!                629   82.1ms    0.3%   131μs   1.95MiB    0.0%  3.18KiB
       ~mesh~                    507   9.46ms    0.0%  18.7μs   5.68MiB    0.1%  11.5KiB
     passive solver              507    548ms    2.0%  1.08ms    752MiB   16.5%  1.48MiB
     solver                      507    534ms    2.0%  1.05ms   0.95GiB   21.4%  1.92MiB
     ~refine~                    585   3.20ms    0.0%  5.47μs    782KiB    0.0%  1.34KiB
   indicator                     585   91.4ms    0.3%   156μs   31.0MiB    0.7%  54.3KiB
   ~AMR~                         585   27.1ms    0.1%  46.3μs   40.3MiB    0.9%  70.5KiB
 Euler solver                  2.93k    8.01s   29.6%  2.73ms   17.0MiB    0.4%  5.93KiB
   rhs!                        2.93k    8.01s   29.6%  2.73ms   17.0MiB    0.4%  5.92KiB
     volume integral           2.93k    6.78s   25.0%  2.31ms   4.20MiB    0.1%  1.47KiB
       blended DG-FV           2.93k    5.39s   19.9%  1.84ms   1.25MiB    0.0%     448B
       pure DG                 2.93k    965ms    3.6%   329μs   1.25MiB    0.0%     448B
       blending factors        2.93k    360ms    1.3%   123μs   1.65MiB    0.0%     591B
       ~volume integral~       2.93k   65.3ms    0.2%  22.3μs   48.6KiB    0.0%    17.0B
     interface flux            2.93k    376ms    1.4%   128μs   1.12MiB    0.0%     400B
     mortar flux               2.93k    251ms    0.9%  85.8μs   1.61MiB    0.0%     576B
     surface integral          2.93k    198ms    0.7%  67.5μs    962KiB    0.0%     336B
     prolong2interfaces        2.93k    136ms    0.5%  46.3μs   1.03MiB    0.0%     368B
     Jacobian                  2.93k   86.5ms    0.3%  29.5μs    870KiB    0.0%     304B
     prolong2mortars           2.93k   81.6ms    0.3%  27.9μs   1.25MiB    0.0%     448B
     reset ∂u/∂t               2.93k   80.0ms    0.3%  27.3μs     0.00B    0.0%    0.00B
     boundary flux             2.93k   11.4ms    0.0%  3.90μs   5.01MiB    0.1%  1.75KiB
     ~rhs!~                    2.93k   6.90ms    0.0%  2.35μs   9.33KiB    0.0%    3.26B
     prolong2boundaries        2.93k   4.04ms    0.0%  1.38μs    962KiB    0.0%     336B
     source terms              2.93k   92.5μs    0.0%  31.6ns     0.00B    0.0%    0.00B
   ~Euler solver~              2.93k   1.27ms    0.0%   433ns      752B    0.0%    0.26B
 analyze solution                  7    263ms    1.0%  37.6ms   14.8MiB    0.3%  2.11MiB
 calculate dt                    587    121ms    0.4%   206μs     0.00B    0.0%    0.00B
 initial condition AMR             1   84.6ms    0.3%  84.6ms   21.4MiB    0.5%  21.4MiB
   AMR                             7   84.0ms    0.3%  12.0ms   21.4MiB    0.5%  3.06MiB
     refine                        7   83.3ms    0.3%  11.9ms   16.4MiB    0.4%  2.35MiB
       solver                      6   71.8ms    0.3%  12.0ms   7.94MiB    0.2%  1.32MiB
       mesh                        6   9.88ms    0.0%  1.65ms    126KiB    0.0%  21.0KiB
         refine_unbalanced!        6   6.52ms    0.0%  1.09ms   4.73KiB    0.0%     808B
         rebalance!               14   3.32ms    0.0%   237μs   54.8KiB    0.0%  3.91KiB
         ~mesh~                    6   48.2μs    0.0%  8.03μs   66.5KiB    0.0%  11.1KiB
       passive solver              6   1.61ms    0.0%   268μs   8.37MiB    0.2%  1.39MiB
       ~refine~                    7   27.0μs    0.0%  3.86μs   14.7KiB    0.0%  2.10KiB
     ~AMR~                         7    474μs    0.0%  67.7μs   4.86MiB    0.1%   710KiB
     indicator                     7    235μs    0.0%  33.5μs    113KiB    0.0%  16.2KiB
     coarsen                       7   1.56μs    0.0%   222ns      448B    0.0%    64.0B
   ~initial condition AMR~         1    598μs    0.0%   598μs   4.77KiB    0.0%  4.77KiB
 ───────────────────────────────────────────────────────────────────────────────────────

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[codecov]

Codecov Report

Attention: Patch coverage is 79.16667% with 5 lines in your changes missing coverage. Please review.

Project coverage is 96.38%. Comparing base (480aea9) to head (3256ecc).

Files with missing lines	Patch %	Lines
...discretization/semidiscretization_euler_gravity.jl	79.17%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2102      +/-   ##
==========================================
+ Coverage   96.34%   96.38%   +0.04%     
==========================================
  Files         470      470              
  Lines       37497    37488       -9     
==========================================
+ Hits        36125    36131       +6     
+ Misses       1372     1357      -15     

Flag	Coverage Δ
unittests	96.38% <79.17%> (+0.04%)	⬆️

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[DanielDoehring]

Hmm, interesting failures for the legacy threaded testsuite. Opinions on this?