- mpiwg-coll - mailman3.cels.anl.gov

Re: [mpi3-coll] January Telecon
by Jesper Larsson Traeff 12 Jan '09

12 Jan '09

Hi all, Thursday fine with me! Jesper On Mon, Jan 05, 2009 at 12:17:24PM -0500, Torsten Hoefler wrote: > Hello MPI-3 Collectives Workgroup, > I'd like to propose the traditional Thursday noon EST time on 01/15/08 > for our next workgroup telecon. Please let me know if there are any > problems with this time so that we can pick another date. > > Thanks & Best, > Torsten > > -- > bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- > Torsten Hoefler | Postdoctoral Researcher > Open Systems Lab | Indiana University > 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA > Lindley Hall Room 135 | +01 (812) 855-3608 > _______________________________________________ > mpi3-coll mailing list > mpi3-coll(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-coll

1 0

Re: [mpi3-coll] January Telecon
by Torsten Hoefler 05 Jan '09

05 Jan '09

On Mon, Jan 05, 2009 at 01:24:01PM -0800, Bronis R. de Supinski wrote: > > Torsten: > > Re: > > I'd like to propose the traditional Thursday noon EST time on 01/15/08 > > for our next workgroup telecon. Please let me know if there are any > > problems with this time so that we can pick another date. > > How long is the call expected to last? I have standing > meetings at 10AM and 11AM Pacific (1PM and 2PM Eastern). The call usually goes 1 hour. The line is cut 1:15pm EST in order to not make it too long. Our past meetings ended well within this time frame. The topics for this telecon are mostly the MPI-3 NBC proposals and related trac tickets and the pending MPI-2.2 proposals (both have absolute priority). We will discuss other MPI-3 items, such as MPI Plans and/or Persistent Collectives, that need more research if time allows (unlikely). > More importantly, what is the call information? I will reserve the call next Monday and announce it (the call information is bound to a particular date/time, and I want to give everybody a chance to influence the meeting time if necessary). Best, Torsten -- bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- Torsten Hoefler | Postdoctoral Researcher Open Systems Lab | Indiana University 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA Lindley Hall Room 135 | +01 (812) 855-3608

1 0

Re: [mpi3-coll] January Telecon
by Bronis R. de Supinski 05 Jan '09

05 Jan '09

Torsten: Re: > I'd like to propose the traditional Thursday noon EST time on 01/15/08 > for our next workgroup telecon. Please let me know if there are any > problems with this time so that we can pick another date. How long is the call expected to last? I have standing meetings at 10AM and 11AM Pacific (1PM and 2PM Eastern). More importantly, what is the call information? Bronis

1 0

[mpi3-coll] January Telecon
by Torsten Hoefler 05 Jan '09

05 Jan '09

Hello MPI-3 Collectives Workgroup, I'd like to propose the traditional Thursday noon EST time on 01/15/08 for our next workgroup telecon. Please let me know if there are any problems with this time so that we can pick another date. Thanks & Best, Torsten -- bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- Torsten Hoefler | Postdoctoral Researcher Open Systems Lab | Indiana University 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA Lindley Hall Room 135 | +01 (812) 855-3608

1 0

Re: [mpi3-coll] Updates after first reading
by Bronis R. de Supinski 02 Jan '09

02 Jan '09

Torsten: I don't think the "cf."s are necessary but that is a style issue that I will not fight over. I don't find any uses of it in the 2.1 standard though. One other issue that I thought was related to Ticket #86 but now realize is really separate. On page 70, lines 6-8 it currently reads: The MPI library must progress and finish the barrier in the MPI_Recv call which eventually completes the barrier operation on both processes and enables the matching MPI_Send. I find the use of "finish" here a bit confusing and unnecessary. We really only need to focus on the Wait in rank 0. I suggest that we reword that paragraph to read: The MPI library must progress the barrier in the MPI_Recv call. Thus, the MPI_Wait call in rank 0 will eventually complete, which enables the matching MPI_Send so all calls eventually return. Bronis On Fri, 2 Jan 2009, Torsten Hoefler wrote: > Hello Bronis, > thank you very much for your detailed review! > > > I do have several other changes to suggest. I will put > > them in terms of the 12-31 version you just announced. > > Oops you just announced another. I'll try to catch any > > changes to pages or line numbers... > sorry for the frequent updates, I try to keep the document as up-to-date > as possible. I don't mind receiving reviews for older versions. I will > merge the editing changes appropriately. > > > I have two other things that I don't report here. One is > > related to ticket #86. > please add your comments to the ticket! > > > I will open a ticket for the other. > Oh yes, that's a good question. I wanted to bring it up at the forum but > ran out of time. I will discuss the ticket in trac. > > > I think it looks like more than it really is. Let me know > > if you have any questions. Thanks, > I will comment your changes below. > > > On page 1, we need to include the cross references for > > the immediate operations as well as the blocking ones. > > This leads to several small changes: > correct, thanks for catching this one (it seems to be incomplete in > MPI-2.1 too (exscan and allreduce is missing - see below). > > > Page 1, line 20: "(Section 5.3)" => "(Sections 5.3 and 5.12.1)" > > Page 1, line 22: "(Section 5.4)" => "(Sections 5.4 and 5.12.2)" > > Page 1, line 25: "(Section 5.5)" => "(Sections 5.5 and 5.12.3)" > > Page 1, line 29: "(Section 5.6)" => "(Sections 5.6 and 5.12.4)" > > Page 1, line 33: "(Section 5.7)" => "(Sections 5.7 and 5.12.5)" > > Page 1, line 37: "(Section 5.8)" => "(Sections 5.8 and 5.12.6)" > all fixed as proposed > > > Page 1, line 43: "(Section 5.9)" => "(Sections 5.9, 5.12.7, and 5.12.8)" > I chose to add a reference to allreduce too (to be consistent) > > > Page 1, line 45: "(Section 5.10)" => "(Sections 5.10 and 5.12.9)" > fixed as proposed > > > Page 1, line 48: "(Section 5.11)" => "(Sections 5.11, 5.12.10, and 5.12.11)" > I also added exscan because it looks like it was forgotten in MPI-2.0 > > > I have a few slightly more complicated changes to suggest for > > page 3. The sentence you added on line 16 ("The collective operations > > do not have a message tag argument.") does not have anything to do > > with type matching so it is misplaced in that location. It fits > > much better with the paragraph on lines 27-30. I think it should > > appear between lines 29 and 30, which would make that paragraph: > > > > Collective communication calls may use the same communicators as > > point-to-point communication; MPI guarantees that messages generated > > on behalf of collective communication calls will not be confused with > > messages generated by point-to-point communication. The collective > > operations do not have a message tag argument. A more detailed > > discussion of correct use of collective routines is found in > > Section 5.13. > excellent! I changed it. > > > I think the intervening paragraph on page 3 (lines 17-26) also > > needs a little rewording and reordering. With the deletions omitted > > for clarity, it currently reads: > > > > Collective routine operations can (but are not required to) > > complete locally as soon as the caller's participation in > > the collective communication is finished. The local completion > > of a collective operation indicates that the caller is now > > free to access locations in the communication buffer. It does > > not indicate that other processes in the group have completed > > or even started the operation (unless otherwise implied by in > > the description of the operation). A blocking operation is > > complete as soon as the call returns. A nonblocking (immediate) > > call requires a separate completion operation, cf. ?? (Section > > 3.7). Thus, a collective communication operation may, or may > > not, have the effect of synchronizing all calling processes. > > This statement excludes, of course, the barrier operation. > > > > The sentences about when operations complete need to appear earlier > > in the paragraph. Where they are currently interferes with the goal > > of stating that completion does not imply synchronization. I also > > suggest a little rewording here: > > > > Collective routine operations can (but are not required to) > > complete locally as soon as the caller's participation in > > the collective communication is finished. A blocking operation > > completes locally as soon as the call returns. A nonblocking > > (immediate) call requires a separate completion operation, > > similarly to nonblocking point-to-point operations as discussed > > in Section 3.7. The local completion of a collective operation > > indicates that the caller is now free to access locations in the > > communication buffer. It does not indicate that other processes > > in the group have completed or even started the operation (unless > > otherwise implied by in the description of the operation). Thus, > > a collective communication operation may, or may not, have the > > effect of synchronizing all calling processes. This statement > > excludes, of course, the barrier operation. > ok, I agree. I thought about this arrangement when I applied the change > originally but decided not to split the first and second sentence (since > they both talk about "local completion". However, after you mentioned it > and I read it again, I agree to your proposal and changed it! > > > I have a few changes for pages 49-50, most of which may just be > > related to how you are setting up for eventual cross-references: > > > > Page 49, line 26: "As described in Chapter ?? (Section 3.7)," => > > "As described in Section 3.7," (use "Section", not "Chapter") > fixed > > > Page 49, line 34: "?? (Section 3)" => "(Section 3.7)" (include > > the word "Section" and the parentheses as well as the subnumber) > I added "described in" to make it a proper sentence - please check! > > > Page 49, line 40: "communicators which would" => "communicators > > that would" (the phrase is required so "that" is correct) > fixed > > > Page 49, line 44: "?? (Section 3.7.1)," => "(Section 3.7.1)," > > (include the parentheses and the word "Section") > added "(cf. Section ...)" > > > Page 50, line 16: "?? (Section 3.7.5)," => "(Section 3.7.5)," > > (include the parentheses and the word "Section") > added "(cf. Section ...)" > > > Page 50, lines 39-40: "refer to ?? (Section 3.7.4)." => "refer to Section > > 3.7.4." (include the word "Section" but not the parentheses) > fixed > > > A general observation is that the descriptions of the operations > > does not discuss intercommunicators. I think something needs to > > be said about how the use of intracommunicators and intercommunicators > > affect the results of the operation for each one. Most of the time, > > this can be handled by adding this phrase: > > > > ",whether on an intracommunicator or an intercommunicator" > ok, I thought we refer to both types when we don't mention this > explicitly. I understand that this proposal makes it clear (explicit) > and I add it. > > > at the end of the sentences that state "data placements are identical > > after the operation completes" or "memory movement after completion is > > identical" or "equivalent to" the blocking operation. These sentences > > specifically occur on: > > page 52, lines 7-8; > fixed > > page 53, lines 36-37; > fixed > > page 54, lines 32-33; > fixed > > page 55, lines 35-36; > fixed > > page 56, lines 33-34; > fixed > > page 57, lines 32-33; > fixed > > page 58, lines 26-27; > fixed > > page 59, lines 32-33; > fixed > > page 61, lines 46-48; > fixed > > page 62, lines 31-32; > fixed > > page 63, lines 25-27; > fixed > > page 64, lines 9-11; > fixed > > page 64, lines 40-41; > fixed > > page 65, lines 24-25. > fixed > > > The statement for MPI_IALLTOALLV is terms of MPI_ALLTOALL so it is > > probably OK as it stands, although perhaps it would be better to > > reword the statement to be in terms of MPI_ALLTOALLV. In fact, I > > suggest adding the following on page 60 at the end of line 30: > > > > The data movement after an MPI_IALLTOALLALLV completes is identical > > to MPI_ALLTOALLV, whether on intracommunicator or an intercommunicator. > I agree, consistency is important, I replaced it by: > > "The data movement after an MPI_IALLTOALLV operation completes is > identical to MPI_ALLTOALLV, whether on intracommunicator or an > intercommunicator." > > > The change for intercommunicators is more complicated for > > MPI_IBARRIER and relates to the outcome of ticket #30 so > > I think we should just make a note of the need for it here; > > maybe add something in parentheses on page 51 > What about defining it in terms of blocking collectives? I replaced the > current description with: > > "On intracommunicators, the operation finishes locally after every > process in the communicator called MPI_IBARRIER. On intracommunicators, > the operation finishes when the MPI_BARRIER call would return." > > > The sentence on page 52, lines 26-27 ("As in many of our example code > > fragments, we assume that some of the variables (such as comm in the > > above) have been assigned appropriate values.") already appears > > earlier in the chapter. There is no need to repeat it here so it > > should be deleted. > ok, I deleted it > > > Page 63, line 26: "operation which delivers" => "operation that delivers" > fixed > > Page 64, line 10: "operation which delivers" => "operation that delivers" > fixed > > Page 64, line 41: "operation which delivers" => "operation that delivers" > fixed > > Page 65, line 25: "operation which delivers" => "operation that delivers" > fixed > > I also edited the text for Alltoallw and Reduce (it also said "which"). > > > On page 66, line 19, you use "cyclic dependency" and on line 23 > > you use "cyclic dependences". It is never clear to me which term > > is correct. I think either is in this case. However, you should > > be consistent. I have a slight preference for "cyclic dependency" > > so I suggest that you change the one on line 23 to "cyclic dependencies" > > although changing the one on line 19 to "cyclic dependence" would > > also be OK with me. > changed as you suggested > > Thank you very much! The new version with your comments added is at [1], > the wiki [2] and the usual diff at [3]! I will follow all relevant trac > tickets. > > Best, > Torsten > > [1]: http://www.unixer.de/sec/nbc-proposal-01-02-2009.pdf > [2]: https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/wiki/NBColl/nbc-pro… > [3]: http://www. unixer.de/sec/nbc-proposal-01-02-2009.diff > > -- > bash$ :(){ :|:&};: --------------------- http:// www. unixer.de/ ----- > Torsten Hoefler | Postdoctoral Researcher > Open Systems Lab | Indiana University > 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA > Lindley Hall Room 135 | +01 (812) 855-3608 >

1 0

Re: [mpi3-coll] Updates after first reading
by Torsten Hoefler 02 Jan '09

02 Jan '09

Hello Bronis, thank you very much for your detailed review! > I do have several other changes to suggest. I will put > them in terms of the 12-31 version you just announced. > Oops you just announced another. I'll try to catch any > changes to pages or line numbers... sorry for the frequent updates, I try to keep the document as up-to-date as possible. I don't mind receiving reviews for older versions. I will merge the editing changes appropriately. > I have two other things that I don't report here. One is > related to ticket #86. please add your comments to the ticket! > I will open a ticket for the other. Oh yes, that's a good question. I wanted to bring it up at the forum but ran out of time. I will discuss the ticket in trac. > I think it looks like more than it really is. Let me know > if you have any questions. Thanks, I will comment your changes below. > On page 1, we need to include the cross references for > the immediate operations as well as the blocking ones. > This leads to several small changes: correct, thanks for catching this one (it seems to be incomplete in MPI-2.1 too (exscan and allreduce is missing - see below). > Page 1, line 20: "(Section 5.3)" => "(Sections 5.3 and 5.12.1)" > Page 1, line 22: "(Section 5.4)" => "(Sections 5.4 and 5.12.2)" > Page 1, line 25: "(Section 5.5)" => "(Sections 5.5 and 5.12.3)" > Page 1, line 29: "(Section 5.6)" => "(Sections 5.6 and 5.12.4)" > Page 1, line 33: "(Section 5.7)" => "(Sections 5.7 and 5.12.5)" > Page 1, line 37: "(Section 5.8)" => "(Sections 5.8 and 5.12.6)" all fixed as proposed > Page 1, line 43: "(Section 5.9)" => "(Sections 5.9, 5.12.7, and 5.12.8)" I chose to add a reference to allreduce too (to be consistent) > Page 1, line 45: "(Section 5.10)" => "(Sections 5.10 and 5.12.9)" fixed as proposed > Page 1, line 48: "(Section 5.11)" => "(Sections 5.11, 5.12.10, and 5.12.11)" I also added exscan because it looks like it was forgotten in MPI-2.0 > I have a few slightly more complicated changes to suggest for > page 3. The sentence you added on line 16 ("The collective operations > do not have a message tag argument.") does not have anything to do > with type matching so it is misplaced in that location. It fits > much better with the paragraph on lines 27-30. I think it should > appear between lines 29 and 30, which would make that paragraph: > > Collective communication calls may use the same communicators as > point-to-point communication; MPI guarantees that messages generated > on behalf of collective communication calls will not be confused with > messages generated by point-to-point communication. The collective > operations do not have a message tag argument. A more detailed > discussion of correct use of collective routines is found in > Section 5.13. excellent! I changed it. > I think the intervening paragraph on page 3 (lines 17-26) also > needs a little rewording and reordering. With the deletions omitted > for clarity, it currently reads: > > Collective routine operations can (but are not required to) > complete locally as soon as the caller's participation in > the collective communication is finished. The local completion > of a collective operation indicates that the caller is now > free to access locations in the communication buffer. It does > not indicate that other processes in the group have completed > or even started the operation (unless otherwise implied by in > the description of the operation). A blocking operation is > complete as soon as the call returns. A nonblocking (immediate) > call requires a separate completion operation, cf. ?? (Section > 3.7). Thus, a collective communication operation may, or may > not, have the effect of synchronizing all calling processes. > This statement excludes, of course, the barrier operation. > > The sentences about when operations complete need to appear earlier > in the paragraph. Where they are currently interferes with the goal > of stating that completion does not imply synchronization. I also > suggest a little rewording here: > > Collective routine operations can (but are not required to) > complete locally as soon as the caller's participation in > the collective communication is finished. A blocking operation > completes locally as soon as the call returns. A nonblocking > (immediate) call requires a separate completion operation, > similarly to nonblocking point-to-point operations as discussed > in Section 3.7. The local completion of a collective operation > indicates that the caller is now free to access locations in the > communication buffer. It does not indicate that other processes > in the group have completed or even started the operation (unless > otherwise implied by in the description of the operation). Thus, > a collective communication operation may, or may not, have the > effect of synchronizing all calling processes. This statement > excludes, of course, the barrier operation. ok, I agree. I thought about this arrangement when I applied the change originally but decided not to split the first and second sentence (since they both talk about "local completion". However, after you mentioned it and I read it again, I agree to your proposal and changed it! > I have a few changes for pages 49-50, most of which may just be > related to how you are setting up for eventual cross-references: > > Page 49, line 26: "As described in Chapter ?? (Section 3.7)," => > "As described in Section 3.7," (use "Section", not "Chapter") fixed > Page 49, line 34: "?? (Section 3)" => "(Section 3.7)" (include > the word "Section" and the parentheses as well as the subnumber) I added "described in" to make it a proper sentence - please check! > Page 49, line 40: "communicators which would" => "communicators > that would" (the phrase is required so "that" is correct) fixed > Page 49, line 44: "?? (Section 3.7.1)," => "(Section 3.7.1)," > (include the parentheses and the word "Section") added "(cf. Section ...)" > Page 50, line 16: "?? (Section 3.7.5)," => "(Section 3.7.5)," > (include the parentheses and the word "Section") added "(cf. Section ...)" > Page 50, lines 39-40: "refer to ?? (Section 3.7.4)." => "refer to Section > 3.7.4." (include the word "Section" but not the parentheses) fixed > A general observation is that the descriptions of the operations > does not discuss intercommunicators. I think something needs to > be said about how the use of intracommunicators and intercommunicators > affect the results of the operation for each one. Most of the time, > this can be handled by adding this phrase: > > ",whether on an intracommunicator or an intercommunicator" ok, I thought we refer to both types when we don't mention this explicitly. I understand that this proposal makes it clear (explicit) and I add it. > at the end of the sentences that state "data placements are identical > after the operation completes" or "memory movement after completion is > identical" or "equivalent to" the blocking operation. These sentences > specifically occur on: > page 52, lines 7-8; fixed > page 53, lines 36-37; fixed > page 54, lines 32-33; fixed > page 55, lines 35-36; fixed > page 56, lines 33-34; fixed > page 57, lines 32-33; fixed > page 58, lines 26-27; fixed > page 59, lines 32-33; fixed > page 61, lines 46-48; fixed > page 62, lines 31-32; fixed > page 63, lines 25-27; fixed > page 64, lines 9-11; fixed > page 64, lines 40-41; fixed > page 65, lines 24-25. fixed > The statement for MPI_IALLTOALLV is terms of MPI_ALLTOALL so it is > probably OK as it stands, although perhaps it would be better to > reword the statement to be in terms of MPI_ALLTOALLV. In fact, I > suggest adding the following on page 60 at the end of line 30: > > The data movement after an MPI_IALLTOALLALLV completes is identical > to MPI_ALLTOALLV, whether on intracommunicator or an intercommunicator. I agree, consistency is important, I replaced it by: "The data movement after an MPI_IALLTOALLV operation completes is identical to MPI_ALLTOALLV, whether on intracommunicator or an intercommunicator." > The change for intercommunicators is more complicated for > MPI_IBARRIER and relates to the outcome of ticket #30 so > I think we should just make a note of the need for it here; > maybe add something in parentheses on page 51 What about defining it in terms of blocking collectives? I replaced the current description with: "On intracommunicators, the operation finishes locally after every process in the communicator called MPI_IBARRIER. On intracommunicators, the operation finishes when the MPI_BARRIER call would return." > The sentence on page 52, lines 26-27 ("As in many of our example code > fragments, we assume that some of the variables (such as comm in the > above) have been assigned appropriate values.") already appears > earlier in the chapter. There is no need to repeat it here so it > should be deleted. ok, I deleted it > Page 63, line 26: "operation which delivers" => "operation that delivers" fixed > Page 64, line 10: "operation which delivers" => "operation that delivers" fixed > Page 64, line 41: "operation which delivers" => "operation that delivers" fixed > Page 65, line 25: "operation which delivers" => "operation that delivers" fixed I also edited the text for Alltoallw and Reduce (it also said "which"). > On page 66, line 19, you use "cyclic dependency" and on line 23 > you use "cyclic dependences". It is never clear to me which term > is correct. I think either is in this case. However, you should > be consistent. I have a slight preference for "cyclic dependency" > so I suggest that you change the one on line 23 to "cyclic dependencies" > although changing the one on line 19 to "cyclic dependence" would > also be OK with me. changed as you suggested Thank you very much! The new version with your comments added is at [1], the wiki [2] and the usual diff at [3]! I will follow all relevant trac tickets. Best, Torsten [1]: http://www.unixer.de/sec/nbc-proposal-01-02-2009.pdf [2]: https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/wiki/NBColl/nbc-pro… [3]: http://www.unixer.de/sec/nbc-proposal-01-02-2009.diff -- bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- Torsten Hoefler | Postdoctoral Researcher Open Systems Lab | Indiana University 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA Lindley Hall Room 135 | +01 (812) 855-3608

1 0

Re: [mpi3-coll] Updates after first reading
by Bronis R. de Supinski 31 Dec '08

31 Dec '08

Torsten: Re: > A small textual update as described in Ticket #93 (applied to > nonblocking collectives). As you might have guessed, I have been reading through the NBC proposal in detail. I created tickets for things that weren't (strictly) related to it -- thanks for catching that the #93 also applied to a portion of it so I don't need to report that here. I do have several other changes to suggest. I will put them in terms of the 12-31 version you just announced. Oops you just announced another. I'll try to catch any changes to pages or line numbers... I have two other things that I don't report here. One is related to ticket #86. I will open a ticket for the other. I think it looks like more than it really is. Let me know if you have any questions. Thanks, Bronis On page 1, we need to include the cross references for the immediate operations as well as the blocking ones. This leads to several small changes: Page 1, line 20: "(Section 5.3)" => "(Sections 5.3 and 5.12.1)" Page 1, line 22: "(Section 5.4)" => "(Sections 5.4 and 5.12.2)" Page 1, line 25: "(Section 5.5)" => "(Sections 5.5 and 5.12.3)" Page 1, line 29: "(Section 5.6)" => "(Sections 5.6 and 5.12.4)" Page 1, line 33: "(Section 5.7)" => "(Sections 5.7 and 5.12.5)" Page 1, line 37: "(Section 5.8)" => "(Sections 5.8 and 5.12.6)" Page 1, line 43: "(Section 5.9)" => "(Sections 5.9, 5.12.7, and 5.12.8)" Page 1, line 45: "(Section 5.10)" => "(Sections 5.10 and 5.12.9)" Page 1, line 48: "(Section 5.11)" => "(Sections 5.11, 5.12.10, and 5.12.11)" I have a few slightly more complicated changes to suggest for page 3. The sentence you added on line 16 ("The collective operations do not have a message tag argument.") does not have anything to do with type matching so it is misplaced in that location. It fits much better with the paragraph on lines 27-30. I think it should appear between lines 29 and 30, which would make that paragraph: Collective communication calls may use the same communicators as point-to-point communication; MPI guarantees that messages generated on behalf of collective communication calls will not be confused with messages generated by point-to-point communication. The collective operations do not have a message tag argument. A more detailed discussion of correct use of collective routines is found in Section 5.13. I think the intervening paragraph on page 3 (lines 17-26) also needs a little rewording and reordering. With the deletions omitted for clarity, it currently reads: Collective routine operations can (but are not required to) complete locally as soon as the caller's participation in the collective communication is finished. The local completion of a collective operation indicates that the caller is now free to access locations in the communication buffer. It does not indicate that other processes in the group have completed or even started the operation (unless otherwise implied by in the description of the operation). A blocking operation is complete as soon as the call returns. A nonblocking (immediate) call requires a separate completion operation, cf. ?? (Section 3.7). Thus, a collective communication operation may, or may not, have the effect of synchronizing all calling processes. This statement excludes, of course, the barrier operation. The sentences about when operations complete need to appear earlier in the paragraph. Where they are currently interferes with the goal of stating that completion does not imply synchronization. I also suggest a little rewording here: Collective routine operations can (but are not required to) complete locally as soon as the caller's participation in the collective communication is finished. A blocking operation completes locally as soon as the call returns. A nonblocking (immediate) call requires a separate completion operation, similarly to nonblocking point-to-point operations as discussed in Section 3.7. The local completion of a collective operation indicates that the caller is now free to access locations in the communication buffer. It does not indicate that other processes in the group have completed or even started the operation (unless otherwise implied by in the description of the operation). Thus, a collective communication operation may, or may not, have the effect of synchronizing all calling processes. This statement excludes, of course, the barrier operation. I have a few changes for pages 49-50, most of which may just be related to how you are setting up for eventual cross-references: Page 49, line 26: "As described in Chapter ?? (Section 3.7)," => "As described in Section 3.7," (use "Section", not "Chapter") Page 49, line 34: "?? (Section 3)" => "(Section 3.7)" (include the word "Section" and the parentheses as well as the subnumber) Page 49, line 40: "communicators which would" => "communicators that would" (the phrase is required so "that" is correct) Page 49, line 44: "?? (Section 3.7.1)," => "(Section 3.7.1)," (include the parentheses and the word "Section") Page 50, line 16: "?? (Section 3.7.5)," => "(Section 3.7.5)," (include the parentheses and the word "Section") Page 50, lines 39-40: "refer to ?? (Section 3.7.4)." => "refer to Section 3.7.4." (include the word "Section" but not the parentheses) A general observation is that the descriptions of the operations does not discuss intercommunicators. I think something needs to be said about how the use of intracommunicators and intercommunicators affect the results of the operation for each one. Most of the time, this can be handled by adding this phrase: ",whether on an intracommunicator or an intercommunicator" at the end of the sentences that state "data placements are identical after the operation completes" or "memory movement after completion is identical" or "equivalent to" the blocking operation. These sentences specifically occur on: page 52, lines 7-8; page 53, lines 36-37; page 54, lines 32-33; page 55, lines 35-36; page 56, lines 33-34; page 57, lines 32-33; page 58, lines 26-27; page 59, lines 32-33; page 61, lines 46-48; page 62, lines 31-32; page 63, lines 25-27; page 64, lines 9-11; page 64, lines 40-41; and page 65, lines 24-25. The statement for MPI_IALLTOALLV is terms of MPI_ALLTOALL so it is probably OK as it stands, although perhaps it would be better to reword the statement to be in terms of MPI_ALLTOALLV. In fact, I suggest adding the following on page 60 at the end of line 30: The data movement after an MPI_IALLTOALLALLV completes is identical to MPI_ALLTOALLV, whether on intracommunicator or an intercommunicator. The change for intercommunicators is more complicated for MPI_IBARRIER and relates to the outcome of ticket #30 so I think we should just make a note of the need for it here; maybe add something in parentheses on page 51 The sentence on page 52, lines 26-27 ("As in many of our example code fragments, we assume that some of the variables (such as comm in the above) have been assigned appropriate values.") already appears earlier in the chapter. There is no need to repeat it here so it should be deleted. Page 63, line 26: "operation which delivers" => "operation that delivers" Page 64, line 10: "operation which delivers" => "operation that delivers" Page 64, line 41: "operation which delivers" => "operation that delivers" Page 65, line 25: "operation which delivers" => "operation that delivers" On page 66, line 19, you use "cyclic dependency" and on line 23 you use "cyclic dependences". It is never clear to me which term is correct. I think either is in this case. However, you should be consistent. I have a slight preference for "cyclic dependency" so I suggest that you change the one on line 23 to "cyclic dependencies" although changing the one on line 19 to "cyclic dependence" would also be OK with me.

1 0

Re: [mpi3-coll] Updates after first reading
by Torsten Hoefler 31 Dec '08

31 Dec '08

Hello, Bronis' comments to Ticket #83 are now also incorporated into the newest proposal. The new version is available at [1] and the wiki [2]. The diff is at [3]. [1]: http://www.unixer.de/sec/nbc-proposal-12-31-2008-2.pdf [2]: https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/wiki/NBColl/nbc-pro… [3]: http://www.unixer.de/sec/nbc-proposal-12-31-2008-2.diff Please review all changes! Best, Torsten -- bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- Torsten Hoefler | Postdoctoral Researcher Open Systems Lab | Indiana University 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA Lindley Hall Room 135 | +01 (812) 855-3608

1 0

Re: [mpi3-coll] Updates after first reading
by Torsten Hoefler 31 Dec '08

31 Dec '08

Hello, A small textual update as described in Ticket #93 (applied to nonblocking collectives). The new version is available at [1] and the wiki [2]. The diff is at [3]. [1]: http://www.unixer.de/sec/nbc-proposal-12-31-2008.pdf [2]: https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/wiki/NBColl/ [3]: http://www.unixer.de/sec/nbc-proposal-12-31-2008.diff Please review all changes! Best, Torsten -- bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- Torsten Hoefler | Postdoctoral Researcher Open Systems Lab | Indiana University 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA Lindley Hall Room 135 | +01 (812) 855-3608

1 0

[mpi3-coll] AUTO: Bin Jia/Poughkeepsie/IBM is out of the office. (returning 01/05/2009)
by Bin Jia 29 Dec '08

29 Dec '08

I am out of the office until 01/05/2009. I will respond to your note when I return. Note: This is an automated response to your message "[mpi3-coll] Updates after first reading" sent on 12/29/08 19:42:01. This is the only notification you will receive while this person is away.

1 0