[Mpi-21] Comments on merged MPI-2.1 document (as per March meeting)

Wed Apr 2 07:51:37 CDT 2008

Jepser,

thank you for your detailed review.
I expect, that I have to hand over all larger suggestions 
to the chapter authors and the typos may be handled after the 
official reading.

Best regards
Rolf

On Wed, 2 Apr 2008 09:36:08 +0200
 Jesper Larsson Traeff <traff_at_it.neclab.eu> wrote:
> 
> Dear All,
> 
> here are my belated comments to the merged MPI 1.2/PI 2.0 document as
> per of the Chicago Forum. Hope they are still useful, perhaps to the
> chapter editors. A lot of the typos and suggestions apply also to the
> already passed MPI 1.3 and MPI 2.1 documents, which I'm afraid are
> finalized now? Especially in the parts concerning the "old", "MPI-1"
> functionality, there is, in my opinion, quite a lot to be done for the
> document to work, as was also discussed at the meeting (deprecation of
> deprecated functions, C++ bindings, MPI-1.2 <-> MPI-2 contradictions,
> ...). In addition to what has been said, it would be good if some of
> us could take the time to make sure the examples are correct,
> effective (in getting the point across - some are very long, and
> somewhat hurried), and do not use deprecated functionality (there's a
> remark on p.25 that the examples have not been checked and verified -
> do we want this?). Now that this merge is being done, I think it is
> important that it will be done well, and we should take the time for
> this.
> 
> Best regards
> 
> Jesper
> 
> Two general consistency things:
> 0.
> count, rank, tag - should be "(nonnegative integer)" in all interface specs
> (in one-sided it is usually so, in pt2pt sometimes so, sometimes just 
> "(integer)"
> 1.
> Is is "high quality" or "high-quality"?
> 
> ii, 15: 
> [TYPO]: documnts -> documents
> 
> Chapter 1:
> [COMM]: In general all the contrasting of MPI-1/MPI-2 reads very
> awkward. Eg. Section 1.2 should be completely eliminated.
> p.1,l.28 [TYPO]: "[8,7]" -> "[7,8]" (refs in ascending order)
> p.3,l.16 [TYPO]: Ref to Chapter 3 is wrong
> p.4,l.13 [SUGG]: Drop "With this version of MPI..."
> p.5,l.26 [TYPO]: Capitalize \textit{send} -> \textit{Send}
> p.6,l.1 [SUGG]: "remove" -> "complement"
> p.7,l.27 [ADD]: Reference to Appendix of Deprecated Functions (as discussed
> at Forum meeting)
> p.7,l.29 [TYPE]: repeats line 26, drop
> p.6,l.35ff [COMM]: The things of JOD that are now in the standard should be
> removed from this discussion.
> 
> Chapter 2:
> p.9,l.16 [SUGG]: Eliminate MPI-1/MPI-2 distinctions, e.g. "MPI Terms and 
> Conventions Chapter"
> p.12,l.29 [SUGG]: Make a reference to definition of typemap (Section 3.12, 
> p.75)
> p.14,l.36 [SUGG]: shouldn't "inquery function" be "query function"?
> p.16,l.24 [TYPO]: "principle" -> "principal"
> p.22,l.23 [TYPO]: "a MIMD style" -> "an MIMD style" (?)
> p.25,l.9 [QUESTION]: Do we really want to stand by this, that the examples
> have "not been carefully checked or verified"???
> 
> Chapter 3:
> [SUGG]: Change the examples (p.27; 3.2, 3.3, 3.4 etc.) such that they'll work
> for any number of processes, eg. make explicit what both ranks do 
> 
> if (myrank == 0) {
> ...
> } else if (myrank == 1) {
> ...
> }
> 
> At least, examples should be consistent, some of the Fortran examples 
> (as in 3.6) mention what rank .EQ. 1 does
> [SUGG]: for count, rank, tag arguments, change "(integer)" to
> "(nonnegative integer)" in all functions descriptions. At least, it
> should be consistent, which ii now not the case
> 
> p.27,l.21 [SUGG]: shouldn't this be "Example 3.1"?
> p.28,l.5 [SUGG]: "(myrank ==1)" reads badly, since it is not in the
> example; make an explicit if-clause (see above)
> p.28,l.29 [COMM]: here count is "(nonnegative integer)", but this
> disappears later, eg. in RECV, p.32,l.4
> p.28,l.33,34 [SUGG]: change "(integer)" to "(nonnegative integer)" for
> dest and tag arguments (and throughout)
> p.29, Tables should contain all (MPI-1 and MPI-2) datatypes. 
> p.30 [SLIP]: MPI_LONG_LONG has disappeared
> p.46,l.28 [QUESTION]: Does the Forum realy want to stand to this 
> (recommendation, almost, of unsafe programming style)??
> p.53,l.29 [SLIP]: drop this line "Section on Argument and register 
> optimization" (similar is elsewhere, seems an edition slip, eg. p.72,l.32)
> p.54,l.15: take line up after "("
> p.58,l.29-30: state explicitly that count is a "(nonnegative integer)".
> Same in all array_of_request functions
> p.59,l.35 [QUESTION]: or is it intended that WAITSOME/TESTSOME takes
> an array of atleast one request?
> p.71,l.7-8: change font of MPI_ANY_SOURCE to sf
> p.76,l.39 [SUGG]: "New Datatype ..." -> "Additional Datatype..."
> p.87,l.1,2,11 [TYPO]: n-dimensional -> $n$-dimensional (or other consistent
> font)
> p.94,l.22: replace deprecated MPI_Address by MPI_Get_address
> p.94,l.45 [TYPO]: refs are wrong
> p.97,l.2 [SUGG]: for "gather" put forward reference to Chapter 4
> p.99,l.32 [TYPO]: "a argument" -> "an argument"
> p.103,l.32 [SUGG]: "ELSE" -> "ELSE IF (rank.EQ.1)"
> p.107,l29 [SUGG]: This example (3.36) could be broken up into smaller
> examples
> p.117,l.22 [SUGG]: change
> "else /* myrank == 1 */"
> into the explicit
> "else if (myrank == 1)"
> (general suggestion)
> p.117,l.41 [TYPO]: concatenate all -> concatenates all
> 
> Chapter 4: This chapter does not work in the merged form.
> p.121,l.48 [TYPO]: "Such processes are called the root" -> "Such a process
> is called the root"
> p.125,l.3 [TYPO]: MPI_Exscan is missing
> p.125,l.35 [TYPO]: drop this line on MPI_Alltoallw
> p.125,l.47 [SUGG]: "additions" is not the right word here (whole section is
> VERY problematic, as is this whole chapter)
> p.127,l.2 [SUGG]: "being identical" must be rephrased
> p.128,l.19 [SUGG]: all count arguments explicitly "(nonnegative integer)"
> p.132,l.82 [TYPO]: left justify closing "}"
> p.135,l.40 [TYPO]: "that that" -> "that"
> p.144,l.43 [TYPO]: "The jth block of data sent" -> "The block of data sent"
> p.151,l.27 [SUGG]: "and a scan (parallel prefix) operation." -> "and
> two scan (parallel prefix) operations."
> p.152,l.38 [TYPO]: join lines up
> p.153,l.5-6 [TYPO]: remove ''
> p.153,l.20 [SUGG]: include MPI_EXSCAN
> p.153,l.33-34 [SUGG]: "xor" -> "exclusive or"
> p.153,l.43ff [TYPO]: format table properly
> p.159,l.160 [SUGG]: add MPI_EXSCAN to list
> p.160,l.34 [TYPO]: "len" in sf font
> p.161,l.20ff [TYPO]: RECV, SEND -> MPI_Recv, MPI_Send + add MPI_Comm_size/rank
> calls to example to set groupsize and rank variables
> p.161,l.35 [TYPO]: group-size -> groupsize
> p.163,l.15 [TYPO]: "MPI includes variants..." -> "MPI includes a variant of
> the reduce operation"
> p.163,l.45ff [TYPO]: description of MPI_IN_PLACE has been corrected?
> p.164,l.31 [TYPO]: "MPI includes variants..." -> "MPI includes a variant
> of the reduce operation..."
> p.166,l.14ff [SUGG]: drop this rationale, since MPI_EXSCAN has now been
> included
> p.166,l.28 [TYPO]: drop
> p.170,l.22 [COMMENT]: In my opinion, this example is NOT correct (the 
> second scenario may hang, process 1 can enter the Bcast which cannot
> complete before process 2 enters Bcast, which it cannot before the Send
> has completed - as in example 4.25)
> 
> Chapter 5: This chapter does not work in the merged form. [SUGG]: since
> the chapter deals also with caching on windows and other objects, change
> title to
> "Groups, contexts, and caching"
> p.175,l.18 [SUGG]: "dealt with so far"... is no longer true
> p.175,l.38-39 [SUGG]: obviously drop lines on no collectives on intercomms
> p.177,l.10 [SUGG]: drop parenthetical remark
> p.177,l.19 [SUGG]: drop ref to next chapter
> p.184,l.22-23 [QUESTION]: Is this advice to implementers needed anymore?
> p.184,l.46-47 [SUGG]: drop parenthetical remark
> p.186,l.20-22 [SUGG]: drop, obviously
> p.190,l.26 [QUESTION]: parenthetical remarks seems strange, drop?
> p.193,l.7 [TYPO]: "the debugging" -> "a debugging"
> p.199,l.28 [SUGG]: "the above examples is really three examples" - why not
> split? The example is too long
> p.200,l.28 [TYPO]: drop "Advice to users:" (twice)
> p.200,l.48 [TYPO]: Obviously drop
> p.201,l.19 [SUGG]: "A group is represented" -> "A group can be represented"
> p.201,l.38 [QUESTION]: what does "the same algorithm is appropriate..." mean?
> p.205, Exsample 1 [SUGG]: very long...
> p.208,l.22 [TYPO]: remove blank space, line tags up. Example is excessively 
> long!
> p.212,l.44 [SUGG]: "you" does not read well, "one can" or sth.
> p.212,l.45 [SUGG]: the other extreme would be not to allow it at all...
> p.213,l.8 [TYPO]: "attributes are attached to communicators" is now wrong
> p.213,l.23 [TYPO]: represents -> requires
> p.217,l.40 [TYPO]: formatting, move lines up
> p.219,l.46 [TYPO]: "the the" -> "then the"
> 
> Chapter 6:
> p.231,l.47 [SUGG]: remove "tremendous"
> p.232,l.17 [SUGG]: remove PARMACS rationale, seems obsolete nowadays
> p.233,l.19 [SUGG]: remove EXPRESS/PARMACS rationale
> 
> Chapter 7:
> p.249,l.5 [SUGG]: "for C" -> "for C and C++"
> p.261-262 [SUGG]: move MPI-2 errir classes into running discussion/tables
> 
> Chapter 8: [SUGG] Rename chapter to
> "Controlling the functionality: The info object"
> or something like this. Any better/good suggestions?
> p.271,l.14 [SUGG]: Remove this line
> p.274,l.36 [TYPO]: change font in (key,value) to sf. Also elsewhere
> p.275,l.5 [TYPO]: font
> p.276,l.37 [TYPO]: font should be $n$th
> 
> Chapter 9:
> p.279,l.21ff [TYPO]: Remove/reformulate this historical/anecdotical remark
> 
> Chapter 10:
> p.312,l.15 [COMM]: Note that here it is said that counts are "(nonnegative
> integers)"; same should be done also for p2p and collectives, also for
> consistency reasons.
> p.313,l.29,l.32 [QUESTION]: is it "high quality" or "high-quality"?
> p.315,l.11 [TYPO]: MPI_TYPE_EXTENT -> MPI_TYPE_GET_EXTENT (also in next
> examples)
> p.330,l.10 [QUESTION]: what is the state of Fortran compilers at this time
> of writing?
> 
> Chapter 11:
> 
> Chapter 12:
> p.432,l.27 [SUGG]: 
> Make reference to subarray constructor definition, 3.12.4, p.86
> 
> Chapter 13:
> p.435,l.24 [SUGG]: modify, only "MPI"
> p.436,l.13 [SUGG]: "as of writing" - this state of affairs has changed
> 
> Chapter 14:
> p.482,l.27 [SUGG]: Section 14.6 can be dropped?
> 
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Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner_at_[hidden]
High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530
University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832
Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner
Nobelstr. 19, D-70550 Stuttgart, Germany . (Office: Allmandring 30)