/[MITgcm]/MITgcm_contrib/llc_hires/llc_1080/code-async/readme.txt
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revision 1.1 by dimitri, Sun Sep 29 22:43:01 2013 UTC revision 1.4 by dimitri, Sat Mar 2 19:31:13 2019 UTC
# Line 1  Line 1 
 Right now some sizes need to be configured manually:  
1    
2  recvTask.c   lines 79-82  In the newest version, it is no longer necessary to hand-edit the
3    constants in "recvTask.c" and "readtile_mpiio.c".  Instead, the file
4    "SIZE.h" has been modified in two ways:
5      (1) SIZE.h  now includes the constant "sFacet"
6      (2) SIZE.h  may now be #include in both C and Fortran files
7    This means that "recvTask.c" and "readtile_mpiio.c" now get the
8    information they need directly from "SIZE.h", so the magic constants
9    for the run only need to be edited in one place (namely, SIZE.h).
10    
 #define NUM_X   4320  
 #define NUM_Y   56160L                     // get rid of this someday  
 #define NUM_Z   90  
 #define MULTDIM  7  
   
   
 and  
   
 readtile_mpiio.c    lines 115-119  
   
    facetElements1D = 4320;  
    tileSizeX = 180;  
    tileSizeY = 180;  
    xGhosts = 8;  
    yGhosts = 8;  
11    
12  One tile per rank is recommended, mostly for pickup input performance,  One tile per rank is recommended, mostly for pickup input performance,
13  but it is not strictly necessary.  but it is not strictly necessary.
# Line 25  Choose dumpFreq and pChkptFreq as usual. Line 16  Choose dumpFreq and pChkptFreq as usual.
16  to do the rolling checkpoints yet. It'll dump u,v,t, and etan now -  to do the rolling checkpoints yet. It'll dump u,v,t, and etan now -
17  send me a list of other fields you want, as it is rather involved  send me a list of other fields you want, as it is rather involved
18  to change them. But this should be enough to see if it works.  to change them. But this should be enough to see if it works.
19    
20    
21    >>>>>>>>>>>>>>>>>>>>>>>>>>>>
22    From Bron, February 28, 2019
23    
24    To use, set run-time parameter: useSingleCPUio=.FALSE.
25    
26    Only a couple of files are different from the sources I copied from you.
27    But note in particular that  "SIZE.h"  is a new file in that directory,
28    and "recvTask.c" has a huge number of changes.
29    
30    
31    A couple of notes:
32    
33    The input scheme implemented here is only invoked on
34    the 64bit pickup files.  It is specific to the LLC decomposition and will
35    not work on e.g. the Monterey high-res simulations we did a couple years
36    ago.  (Although, the code should work for any facet size as specified
37    in SIZE.h)  The format of SIZE.h was changed so that it can be included
38    in both C and Fortran files, and I also added the "sFacet" constant that
39    specifies the base facet size (e.g. 1080).  So SIZE.h will probably look
40    kinda weird at first, but shouldn't be hard to figure out.  The major
41    advantage is that now you no longer need to edit any magic constants in
42    recvTask.c and readtile_mpiio.c - they now derive the info they need by
43    directly including SIZE.h
44    
45    The code now automatically figures out how many ranks are running per node.
46    You can run with whatever number of ranks per node that you want, but the
47    number needs to be consistent for all nodes (except possibly the last node,
48    which can be short).
49    
50    The initial burst of output generated by recvTask.c (the "map" describing
51    the way the I/O processes are allocated) is now somewhat longer and more
52    detailed, but can continue to be ignored.
53    
54    I did NOT try to cure the "integer" problem.  It seems that the code is
55    getting fairly close to bumping into the 2G (i.e. 2^31) limit on numbers
56    that fit into a default integer.  I *think* you can probably do one more
57    doubling of the resolution (to 8640), but I'm also pretty sure that going
58    past that will break the code.

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