/[MITgcm]/MITgcm/eesupp/inc/CPP_EEOPTIONS.h
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Revision 1.36 - (hide annotations) (download)
Sat Sep 28 19:09:38 2013 UTC (10 years, 7 months ago) by dimitri
Branch: MAIN
CVS Tags: checkpoint64q, checkpoint64p, checkpoint64s, checkpoint64r, checkpoint64u, checkpoint64t, checkpoint64w, checkpoint64v
Changes since 1.35: +5 -1 lines
File MIME type: text/plain
Added SINGLE_DISK_IO option for use with MPI on very large number of
processors and Lustre-type file systems.

1 dimitri 1.36 C $Header: /u/gcmpack/MITgcm/eesupp/inc/CPP_EEOPTIONS.h,v 1.35 2012/09/06 21:55:59 jmc Exp $
2 adcroft 1.17 C $Name: $
3    
4 cnh 1.18 CBOP
5     C !ROUTINE: CPP_EEOPTIONS.h
6     C !INTERFACE:
7     C include "CPP_EEOPTIONS.h"
8 cnh 1.1 C
9 cnh 1.18 C !DESCRIPTION:
10     C *==========================================================*
11 edhill 1.22 C | CPP\_EEOPTIONS.h |
12 cnh 1.18 C *==========================================================*
13 cnh 1.1 C | C preprocessor "execution environment" supporting |
14     C | flags. Use this file to set flags controlling the |
15     C | execution environment in which a model runs - as opposed |
16     C | to the dynamical problem the model solves. |
17     C | Note: Many options are implemented with both compile time|
18     C | and run-time switches. This allows options to be |
19     C | removed altogether, made optional at run-time or |
20     C | to be permanently enabled. This convention helps |
21     C | with the data-dependence analysis performed by the |
22     C | adjoint model compiler. This data dependency |
23     C | analysis can be upset by runtime switches that it |
24     C | is unable to recoginise as being fixed for the |
25     C | duration of an integration. |
26     C | A reasonable way to use these flags is to |
27     C | set all options as selectable at runtime but then |
28     C | once an experimental configuration has been |
29     C | identified, rebuild the code with the appropriate |
30     C | options set at compile time. |
31 cnh 1.18 C *==========================================================*
32     CEOP
33 cnh 1.1
34 adcroft 1.4 #ifndef _CPP_EEOPTIONS_H_
35     #define _CPP_EEOPTIONS_H_
36    
37 cnh 1.1 C In general the following convention applies:
38     C ALLOW - indicates an feature will be included but it may
39     C CAN have a run-time flag to allow it to be switched
40     C on and off.
41     C If ALLOW or CAN directives are "undef'd" this generally
42     C means that the feature will not be available i.e. it
43     C will not be included in the compiled code and so no
44     C run-time option to use the feature will be available.
45     C
46     C ALWAYS - indicates the choice will be fixed at compile time
47     C so no run-time option will be present
48    
49 jmc 1.33 C=== Macro related options ===
50     C-- Control storage of floating point operands
51     C On many systems it improves performance only to use
52     C 8-byte precision for time stepped variables.
53     C Constant in time terms ( geometric factors etc.. )
54     C can use 4-byte precision, reducing memory utilisation and
55     C boosting performance because of a smaller working set size.
56     C However, on vector CRAY systems this degrades performance.
57     C Enable to switch REAL4_IS_SLOW from genmake2 (with LET_RS_BE_REAL4):
58     #ifdef LET_RS_BE_REAL4
59     #undef REAL4_IS_SLOW
60     #else /* LET_RS_BE_REAL4 */
61     #define REAL4_IS_SLOW
62     #endif /* LET_RS_BE_REAL4 */
63    
64     C-- Control use of "double" precision constants.
65     C Use D0 where it means REAL*8 but not where it means REAL*16
66     #define D0 d0
67    
68     C-- Enable some old macro conventions for backward compatibility
69     #undef USE_OLD_MACROS_R4R8toRSRL
70    
71     C=== IO related options ===
72 jmc 1.25 C-- Flag used to indicate whether Fortran formatted write
73 cnh 1.1 C and read are threadsafe. On SGI the routines can be thread
74     C safe, on Sun it is not possible - if you are unsure then
75     C undef this option.
76 jmc 1.25 #undef FMTFTN_IO_THREAD_SAFE
77    
78     C-- Flag used to indicate whether Binary write to Local file (i.e.,
79     C a different file for each tile) and read are thread-safe.
80     #undef LOCBIN_IO_THREAD_SAFE
81    
82     C-- Flag to turn off the writing of error message to ioUnit zero
83     #undef DISABLE_WRITE_TO_UNIT_ZERO
84 cnh 1.1
85 jmc 1.33 C-- Alternative formulation of BYTESWAP, faster than
86     C compiler flag -byteswapio on the Altix.
87     #undef FAST_BYTESWAP
88 jmc 1.30
89 dimitri 1.36 C-- Flag defined for eeset_parms.F and open_copy_data_file.F
90     C to write scratch files from process 0 only
91     #undef SINGLE_DISK_IO
92    
93 jmc 1.33 C=== MPI, EXCH and GLOBAL_SUM related options ===
94 dimitri 1.26 C-- Flag turns off MPI_SEND ready_to_receive polling in the
95     C gather_* subroutines to speed up integrations.
96     #undef DISABLE_MPI_READY_TO_RECEIVE
97    
98 cnh 1.1 C-- Control MPI based parallel processing
99 adcroft 1.19 CXXX We no longer select the use of MPI via this file (CPP_EEOPTIONS.h)
100     CXXX To use MPI, use an appropriate genmake2 options file or use
101     CXXX genmake2 -mpi .
102     CXXX #undef ALLOW_USE_MPI
103 jmc 1.25
104 cnh 1.1 C-- Control use of communication that might overlap computation.
105     C Under MPI selects/deselects "non-blocking" sends and receives.
106     #define ALLOW_ASYNC_COMMUNICATION
107     #undef ALLOW_ASYNC_COMMUNICATION
108     #undef ALWAYS_USE_ASYNC_COMMUNICATION
109     C-- Control use of communication that is atomic to computation.
110     C Under MPI selects/deselects "blocking" sends and receives.
111     #define ALLOW_SYNC_COMMUNICATION
112     #undef ALWAYS_USE_SYNC_COMMUNICATION
113 adcroft 1.13
114     C-- Control use of JAM routines for Artic network
115     C These invoke optimized versions of "exchange" and "sum" that
116     C utilize the programmable aspect of Artic cards.
117 jmc 1.33 CXXX No longer supported ; started to remove JAM routines.
118     CXXX #undef LETS_MAKE_JAM
119     CXXX #undef JAM_WITH_TWO_PROCS_PER_NODE
120 cnh 1.1
121     C-- Control XY periodicity in processor to grid mappings
122 jmc 1.25 C Note: Model code does not need to know whether a domain is
123 cnh 1.1 C periodic because it has overlap regions for every box.
124 cnh 1.10 C Model assume that these values have been
125 cnh 1.1 C filled in some way.
126     #undef ALWAYS_PREVENT_X_PERIODICITY
127     #undef ALWAYS_PREVENT_Y_PERIODICITY
128     #define CAN_PREVENT_X_PERIODICITY
129     #define CAN_PREVENT_Y_PERIODICITY
130    
131 jmc 1.34 C-- disconnect tiles (no exchange between tiles, just fill-in edges
132     C assuming locally periodic subdomain)
133     #undef DISCONNECTED_TILES
134    
135 jmc 1.28 C-- Alternative way of doing global sum without MPI allreduce call
136     C but instead, explicit MPI send & recv calls.
137     #undef GLOBAL_SUM_SEND_RECV
138    
139 jahn 1.29 C-- Alternative way of doing global sum on a single CPU
140     C to eliminate tiling-dependent roundoff errors.
141     C Note: This is slow.
142     #undef CG2D_SINGLECPU_SUM
143    
144 jmc 1.33 C=== Other options (to add/remove pieces of code) ===
145     C-- Flag to turn on checking for errors from all threads and procs
146     C (calling S/R STOP_IF_ERROR) before stopping.
147     #define USE_ERROR_STOP
148    
149     C-- Control use of communication with other component:
150     C allow to import and export from/to Coupler interface.
151     #undef COMPONENT_MODULE
152 heimbach 1.32
153 adcroft 1.14 #endif /* _CPP_EEOPTIONS_H_ */
154 cnh 1.3
155 adcroft 1.14 #include "CPP_EEMACROS.h"
156 edhill 1.23

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