January 2021 - discuss - mailman3.cels.anl.gov

Re: [mpich-discuss] Download Help
by Zhou, Hui 28 Jan '21

28 Jan '21

Jesse Jen, Could you try ./configure --prefix=/home/jje/mpich-install –with-device=ch4:ofi? -- Hui Zhou From: Jesse Jen via discuss <discuss(a)mpich.org> Date: Thursday, January 28, 2021 at 4:43 PM To: discuss(a)mpich.org <discuss(a)mpich.org> Cc: Jesse Jen <jessejenjj(a)gmail.com> Subject: [mpich-discuss] Download Help I am currently downloading the latest version of mpich on a ubuntu machine. I am having trouble configuring (step 1d) as I do not understand the error messages. How do i proceed? The error message I receive at the bottom is: This is the input: root@master:/home/jje/mpich-3.4rc1# ./configure --prefix=/home/jje/mpich-install 2>&1 | tee c.txt The error message I receive at the bottom is: configure: error: no ch4 netmod selected The default ch4 device could not detect a preferred network library. Supported options are ofi (libfabric) and ucx: --with-device=ch4:ofi or --with-device=ch4:ucx Configure will use an embedded copy of libfabric or ucx if one is not found in the user environment. An installation can be specified by adding --with-libfabric=<path/to/install> or --with-ucx=<path/to/install> to the configuration. The previous MPICH default device (ch3) is also available and supported with option: --with-device=ch3 Here is a imgur link with everything in between: https://imgur.com/a/RvuALd0 Thank You

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Download Help
by Jesse Jen 28 Jan '21

28 Jan '21

I am currently downloading the latest version of mpich on a ubuntu machine. I am having trouble configuring (step 1d) as I do not understand the error messages. How do i proceed? The error message I receive at the bottom is: This is the input: root@master:/home/jje/mpich-3.4rc1# ./configure --prefix=/home/jje/mpich-install 2>&1 | tee c.txt The error message I receive at the bottom is: configure: error: no ch4 netmod selected The default ch4 device could not detect a preferred network library. Supported options are ofi (libfabric) and ucx: --with-device=ch4:ofi or --with-device=ch4:ucx Configure will use an embedded copy of libfabric or ucx if one is not found in the user environment. An installation can be specified by adding --with-libfabric=<path/to/install> or --with-ucx=<path/to/install> to the configuration. The previous MPICH default device (ch3) is also available and supported with option: --with-device=ch3 Here is a imgur link with everything in between: https://imgur.com/a/RvuALd0 Thank You

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Re: [mpich-discuss] Is it okay to remove F77 support?
by Zhou, Hui 28 Jan '21

28 Jan '21

No worries. For the record, your first letter of panic is not minded and welcome. It is important for us to care about what user worries. Just to explain, MPICH, as an implementation of MPI specification, will never propose dropping part of standard such as mpif.h. In fact, we even keep deprecated features as long as we can unless it conflicts with new feature. Even then, we’ll consider configure options if the change will have significant impact. Rest assured, mpif.h is very much safe. Just to explain my original question. There is always a risk when MPICH is compiled by certain Fortran compiler, and the user code is by another Fortran compiler. Different compilers are not necessarily binary compatible and may not link against each other. So if MPICH requires newer compiler, and your code requires some other compiler, then that is a potential concern that needs study. My question was to see if such concern exist. -- Hui Zhou From: Gus Correa <gus(a)ldeo.columbia.edu> Date: Thursday, January 28, 2021 at 1:01 AM To: Zhou, Hui <zhouh(a)anl.gov> Cc: discuss(a)mpich.org <discuss(a)mpich.org> Subject: Re: [mpich-discuss] Is it okay to remove F77 support? Dear Hui Zhou. Thank you. On your second posting on this thread I understood the problem boiled down to a misunderstanding caused by the subject line, and that the support for the MPICH Fortran-77 API was not at risk of being dropped. That took away the worries, and I recognized this in my subsequent posting. After that, other than Jeff Squyres clarifying posting, everything else didn't really matter, was just noise, as the issue had been already clarified, the problem was solved. I appreciate your efforts and those of the MPICH team, to keep the project user oriented. In the past I have posted questions on this mailing list, and I received valuable (and valued, rest assured) help from Pavan Balaji and other list subscribers. Although my initial concern was genuine - there is a lot of Fortran-77 code here and out there that uses and depends on MPI and MPICH and that would be orphaned if the Fortran-77 MPI API was to be dropped - I should have toned down my first posting, and I apologize to you if it sounded rough. Thank you, Gus Correa On Wed, Jan 27, 2021 at 11:23 PM Zhou, Hui <zhouh(a)anl.gov<mailto:[email protected]>> wrote: Dear Gus Correa, There are some misunderstanding, not all posts are coming from or representing MPICH team. The original question, by me, is from MPICH team, and I personally, not the team nor Argonne, take the full responsibility of “badly written subject line”. Most other posts are from different entities and most of them only reflect their personal views anyway. As a discussion mailing list, we should assume all posts represent personal view by default. That said, all inputs are valued here. Frank opinions and voices are what makes better software and better user experiences. Since we have spent several rounds of email clarifying the question, and since you understood the initial false alarm and misunderstanding, I am hoping we can put this behind us and not to hold grudges or at least not to hold it long. If you believe, after clearing the initial misunderstanding, that the topic is not of interest to you, please ignore rest of the thread. Meanwhile, I do believe the question is meaningful to ask. So please don’t dismiss the discussion just out of your perspective. -- Hui Zhou From: Gus Correa via discuss <discuss(a)mpich.org<mailto:[email protected]>> Date: Wednesday, January 27, 2021 at 9:27 PM To: MPICH-Discuss <discuss(a)mpich.org<mailto:[email protected]>> Cc: Gus Correa <gus(a)ldeo.columbia.edu<mailto:[email protected]>> Subject: Re: [mpich-discuss] Is it okay to remove F77 support? Oh Mr. Hammond, you guys are just die-hards, insisting to defend what you just did, namely alarm your community of users with your terribly phrased question. The original question, at the very subject line of the email, was very poorly formulated, and suggested the end of mpi.f and such, which are essential in code written in all sorts of Fortran-77 code (and various F77 extensions) that abound among your users. Don't you care about these users (us)? Being pedantic, belittling your users alarm after your horrible question, or berating your users knowledge of what is and what is not strict F77 ISO standard doesn't help at all. After all, we, your users, in one way or another, as taxpayers and in other ways, support the development of publicly available high quality software in national labs, such as mpich, expecting that it will be useful and usable, and work together (not against) the codes we have. So presumably we deserve a little better. The bad question triggered a whole discussion, which subsequent answers showed to be a discussion about nothing. Period. Jeff Squyres pointed out that it was never possible to build MPI with a compiler strictly adherent to Fortran-77 ISO standard. So, why, as the initial question asked, do you need to remove support for something that never existed to begin with? Why do you need to ask this non-question to the community, and raise the false alarm? Huh. Indeed, I never paid much attention to that, but admittedly I have been compiling OpenMPI, MPICH and MVAPICH all with F90 compilers (gfortran, pgfortran, ifort), although often times using their Fortran-77 versions (with extensions to the ISO standard I suppose), to compile code that depends on Many of those codes do depend on mpi.f, won't work with F90 modules (or 'use mpi'). I guess this is not unique at all, and a lot of the code base out there, in various areas of knowledge, works this way. The original question clearly suggested suppressing this possibility. Gus Correa On Wed, Jan 27, 2021 at 12:16 PM Jeff Hammond <jeff.science(a)gmail.com<mailto:[email protected]>> wrote: Squyres' point is that there is not and has never been an MPI Fortran 77 API and every time someone implies there is, it confuses people. mpif.h requires ISO Fortran 90 - it just happens to support fixed-source form and does not require any of the Fortran 90 features that were not ubiquitous in compilers ~15 years ago. The original question was correct, but could not be interpreted correctly by most people. It asked whether MPICH could drop support for compilers that support no Fortran dialect beyond Fortran 77. The only compiler I have ever used that would be impacted by this is g77, which I used in the same era that I used Itanium. Jeff Well, then the question was very poorly formulated. It suggests suppressing the Mpich Fortran-77 API. Hard to gauge the impact of removing support of F77 compiler (ONLY), but it may cause trouble when building complex code, and linking it to MPI (mpich), as some may actually require a compiler that is specific for Fortran-77, or have Makefiles and other utilities that rely on such a compiler. Gus Correa _______________________________________________ discuss mailing list discuss(a)mpich.org<mailto:[email protected]> To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss -- Jeff Hammond jeff.science(a)gmail.com<mailto:[email protected]> http://jeffhammond.github.io/

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Re: [mpich-discuss] Is it okay to remove F77 support?
by Gus Correa 28 Jan '21

28 Jan '21

Dear Hui Zhou. Thank you. On your second posting on this thread I understood the problem boiled down to a misunderstanding caused by the subject line, and that the support for the MPICH Fortran-77 API was not at risk of being dropped. That took away the worries, and I recognized this in my subsequent posting. After that, other than Jeff Squyres clarifying posting, everything else didn't really matter, was just noise, as the issue had been already clarified, the problem was solved. I appreciate your efforts and those of the MPICH team, to keep the project user oriented. In the past I have posted questions on this mailing list, and I received valuable (and valued, rest assured) help from Pavan Balaji and other list subscribers. Although my initial concern was genuine - there is a lot of Fortran-77 code here and out there that uses and depends on MPI and MPICH and that would be orphaned if the Fortran-77 MPI API was to be dropped - I should have toned down my first posting, and I apologize to you if it sounded rough. Thank you, Gus Correa On Wed, Jan 27, 2021 at 11:23 PM Zhou, Hui <zhouh(a)anl.gov> wrote: > Dear Gus Correa, > > > > There are some misunderstanding, not all posts are coming from or > representing MPICH team. The original question, by me, is from MPICH team, > and I personally, not the team nor Argonne, take the full responsibility of > “badly written subject line”. Most other posts are from different entities > and most of them only reflect their personal views anyway. As a discussion > mailing list, we should assume all posts represent personal view by > default. That said, all inputs are valued here. Frank opinions and voices > are what makes better software and better user experiences. Since we have > spent several rounds of email clarifying the question, and since you > understood the initial false alarm and misunderstanding, I am hoping we can > put this behind us and not to hold grudges or at least not to hold it long. > > > > If you believe, after clearing the initial misunderstanding, that the > topic is not of interest to you, please ignore rest of the thread. > Meanwhile, I do believe the question is meaningful to ask. So please don’t > dismiss the discussion just out of your perspective. > > > > -- > Hui Zhou > > > > > > *From: *Gus Correa via discuss <discuss(a)mpich.org> > *Date: *Wednesday, January 27, 2021 at 9:27 PM > *To: *MPICH-Discuss <discuss(a)mpich.org> > *Cc: *Gus Correa <gus(a)ldeo.columbia.edu> > *Subject: *Re: [mpich-discuss] Is it okay to remove F77 support? > > Oh Mr. Hammond, you guys are just die-hards, insisting to defend what you > just did, > > namely alarm your community of users with your terribly phrased question. > > > > The original question, at the very subject line of the email, > > was very poorly formulated, and suggested the end of mpi.f and such, > > which are essential in code written in all sorts of > > Fortran-77 code (and various F77 extensions) that abound > > among your users. > > Don't you care about these users (us)? > > > > Being pedantic, belittling your users alarm after your horrible question, > > or berating your users knowledge of what is and what is not strict F77 ISO > standard > > doesn't help at all. > > After all, we, your users, in one way or another, > > as taxpayers and in other ways, > > support the development of publicly available high quality > > software in national labs, such as mpich, expecting that it will > > be useful and usable, and work together (not against) the codes we have. > > So presumably we deserve a little better. > > > > The bad question triggered a whole discussion, > > which subsequent answers showed to be a discussion about nothing. > > Period. > > > > Jeff Squyres pointed out that it was never possible to build > > MPI with a compiler strictly adherent to Fortran-77 ISO standard. > > > > So, why, as the initial question asked, do you need to remove > > support for something that never existed to begin with? > > Why do you need to ask this non-question to the community, > > and raise the false alarm? > > Huh. > > > > Indeed, I never paid much attention to that, > > but admittedly I have been compiling OpenMPI, MPICH and MVAPICH > > all with F90 compilers (gfortran, pgfortran, ifort), although often > > times using their Fortran-77 versions (with extensions to the ISO standard > I suppose), > > to compile code that depends on > > Many of those codes do depend on mpi.f, won't work with F90 modules (or > 'use mpi'). > > I guess this is not unique at all, and a lot of the code base out there, > > in various areas of knowledge, works this way. > > The original question clearly suggested suppressing this possibility. > > > > > > Gus Correa > > > > On Wed, Jan 27, 2021 at 12:16 PM Jeff Hammond <jeff.science(a)gmail.com> > wrote: > > Squyres' point is that there is not and has never been an MPI Fortran 77 > API and every time someone implies there is, it confuses people. mpif.h > requires ISO Fortran 90 - it just happens to support fixed-source form and > does not require any of the Fortran 90 features that were not ubiquitous in > compilers ~15 years ago. > > > > The original question was correct, but could not be interpreted correctly > by most people. It asked whether MPICH could drop support for compilers > that support no Fortran dialect beyond Fortran 77. The only compiler I > have ever used that would be impacted by this is g77, which I used in the > same era that I used Itanium. > > > > Jeff > > > > > > Well, then the question was very poorly formulated. > > It suggests suppressing the Mpich Fortran-77 API. > > > > Hard to gauge the impact of removing support of F77 compiler (ONLY), > > but it may cause trouble when building complex code, > > and linking it to MPI (mpich), > > as some may actually require a compiler that is specific for Fortran-77, > > or have Makefiles and other utilities that rely on such a compiler. > > > > Gus Correa > > _______________________________________________ > discuss mailing list discuss(a)mpich.org > To manage subscription options or unsubscribe: > https://lists.mpich.org/mailman/listinfo/discuss > > > > > -- > > Jeff Hammond > jeff.science(a)gmail.com > http://jeffhammond.github.io/ > >

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Re: [mpich-discuss] Is it okay to remove F77 support?
by Zhou, Hui 27 Jan '21

27 Jan '21

Dear Gus Correa, There are some misunderstanding, not all posts are coming from or representing MPICH team. The original question, by me, is from MPICH team, and I personally, not the team nor Argonne, take the full responsibility of “badly written subject line”. Most other posts are from different entities and most of them only reflect their personal views anyway. As a discussion mailing list, we should assume all posts represent personal view by default. That said, all inputs are valued here. Frank opinions and voices are what makes better software and better user experiences. Since we have spent several rounds of email clarifying the question, and since you understood the initial false alarm and misunderstanding, I am hoping we can put this behind us and not to hold grudges or at least not to hold it long. If you believe, after clearing the initial misunderstanding, that the topic is not of interest to you, please ignore rest of the thread. Meanwhile, I do believe the question is meaningful to ask. So please don’t dismiss the discussion just out of your perspective. -- Hui Zhou From: Gus Correa via discuss <discuss(a)mpich.org> Date: Wednesday, January 27, 2021 at 9:27 PM To: MPICH-Discuss <discuss(a)mpich.org> Cc: Gus Correa <gus(a)ldeo.columbia.edu> Subject: Re: [mpich-discuss] Is it okay to remove F77 support? Oh Mr. Hammond, you guys are just die-hards, insisting to defend what you just did, namely alarm your community of users with your terribly phrased question. The original question, at the very subject line of the email, was very poorly formulated, and suggested the end of mpi.f and such, which are essential in code written in all sorts of Fortran-77 code (and various F77 extensions) that abound among your users. Don't you care about these users (us)? Being pedantic, belittling your users alarm after your horrible question, or berating your users knowledge of what is and what is not strict F77 ISO standard doesn't help at all. After all, we, your users, in one way or another, as taxpayers and in other ways, support the development of publicly available high quality software in national labs, such as mpich, expecting that it will be useful and usable, and work together (not against) the codes we have. So presumably we deserve a little better. The bad question triggered a whole discussion, which subsequent answers showed to be a discussion about nothing. Period. Jeff Squyres pointed out that it was never possible to build MPI with a compiler strictly adherent to Fortran-77 ISO standard. So, why, as the initial question asked, do you need to remove support for something that never existed to begin with? Why do you need to ask this non-question to the community, and raise the false alarm? Huh. Indeed, I never paid much attention to that, but admittedly I have been compiling OpenMPI, MPICH and MVAPICH all with F90 compilers (gfortran, pgfortran, ifort), although often times using their Fortran-77 versions (with extensions to the ISO standard I suppose), to compile code that depends on Many of those codes do depend on mpi.f, won't work with F90 modules (or 'use mpi'). I guess this is not unique at all, and a lot of the code base out there, in various areas of knowledge, works this way. The original question clearly suggested suppressing this possibility. Gus Correa On Wed, Jan 27, 2021 at 12:16 PM Jeff Hammond <jeff.science(a)gmail.com<mailto:[email protected]>> wrote: Squyres' point is that there is not and has never been an MPI Fortran 77 API and every time someone implies there is, it confuses people. mpif.h requires ISO Fortran 90 - it just happens to support fixed-source form and does not require any of the Fortran 90 features that were not ubiquitous in compilers ~15 years ago. The original question was correct, but could not be interpreted correctly by most people. It asked whether MPICH could drop support for compilers that support no Fortran dialect beyond Fortran 77. The only compiler I have ever used that would be impacted by this is g77, which I used in the same era that I used Itanium. Jeff Well, then the question was very poorly formulated. It suggests suppressing the Mpich Fortran-77 API. Hard to gauge the impact of removing support of F77 compiler (ONLY), but it may cause trouble when building complex code, and linking it to MPI (mpich), as some may actually require a compiler that is specific for Fortran-77, or have Makefiles and other utilities that rely on such a compiler. Gus Correa _______________________________________________ discuss mailing list discuss(a)mpich.org<mailto:[email protected]> To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss -- Jeff Hammond jeff.science(a)gmail.com<mailto:[email protected]> http://jeffhammond.github.io/

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Re: [mpich-discuss] Is it okay to remove F77 support?
by Gus Correa 27 Jan '21

27 Jan '21

Oh Mr. Hammond, you guys are just die-hards, insisting to defend what you just did, namely alarm your community of users with your terribly phrased question. The original question, at the very subject line of the email, was very poorly formulated, and suggested the end of mpi.f and such, which are essential in code written in all sorts of Fortran-77 code (and various F77 extensions) that abound among your users. Don't you care about these users (us)? Being pedantic, belittling your users alarm after your horrible question, or berating your users knowledge of what is and what is not strict F77 ISO standard doesn't help at all. After all, we, your users, in one way or another, as taxpayers and in other ways, support the development of publicly available high quality software in national labs, such as mpich, expecting that it will be useful and usable, and work together (not against) the codes we have. So presumably we deserve a little better. The bad question triggered a whole discussion, which subsequent answers showed to be a discussion about nothing. Period. Jeff Squyres pointed out that it was never possible to build MPI with a compiler strictly adherent to Fortran-77 ISO standard. So, why, as the initial question asked, do you need to remove support for something that never existed to begin with? Why do you need to ask this non-question to the community, and raise the false alarm? Huh. Indeed, I never paid much attention to that, but admittedly I have been compiling OpenMPI, MPICH and MVAPICH all with F90 compilers (gfortran, pgfortran, ifort), although often times using their Fortran-77 versions (with extensions to the ISO standard I suppose), to compile code that depends on Many of those codes do depend on mpi.f, won't work with F90 modules (or 'use mpi'). I guess this is not unique at all, and a lot of the code base out there, in various areas of knowledge, works this way. The original question clearly suggested suppressing this possibility. Gus Correa On Wed, Jan 27, 2021 at 12:16 PM Jeff Hammond <jeff.science(a)gmail.com> wrote: > Squyres' point is that there is not and has never been an MPI Fortran 77 > API and every time someone implies there is, it confuses people. mpif.h > requires ISO Fortran 90 - it just happens to support fixed-source form and > does not require any of the Fortran 90 features that were not ubiquitous in > compilers ~15 years ago. > > The original question was correct, but could not be interpreted correctly > by most people. It asked whether MPICH could drop support for compilers > that support no Fortran dialect beyond Fortran 77. The only compiler I > have ever used that would be impacted by this is g77, which I used in the > same era that I used Itanium. > > Jeff > > >> Well, then the question was very poorly formulated. >> It suggests suppressing the Mpich Fortran-77 API. >> >> Hard to gauge the impact of removing support of F77 compiler (ONLY), >> but it may cause trouble when building complex code, >> and linking it to MPI (mpich), >> as some may actually require a compiler that is specific for Fortran-77, >> or have Makefiles and other utilities that rely on such a compiler. >> >> Gus Correa >> _______________________________________________ >> discuss mailing list discuss(a)mpich.org >> To manage subscription options or unsubscribe: >> https://lists.mpich.org/mailman/listinfo/discuss >> > > > -- > Jeff Hammond > jeff.science(a)gmail.com > http://jeffhammond.github.io/ >

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Re: [mpich-discuss] GPU support for MPICH
by Zhou, Hui 27 Jan '21

27 Jan '21

If `configure` detects CUDA runtime, GPU support is always enabled. You can pass in `--with-cuda=path/to/cuda` for custom CUDA locations. Unfortunately, there isn’t an obvious way to disable GPU support if CUDA library is in the system path. -- Hui Zhou From: Palmer, Bruce J via discuss <discuss(a)mpich.org> Date: Wednesday, January 27, 2021 at 3:55 PM To: discuss(a)mpich.org <discuss(a)mpich.org> Cc: Palmer, Bruce J <Bruce.Palmer(a)pnnl.gov> Subject: [mpich-discuss] GPU support for MPICH Hi, I just downloaded mpich-3.4.1 and I want to try and configure and build it with GPU support. There doesn’t appear to be any documentation on how to go about this, or at least it is very well hidden. Can you tell me where to find information? Bruce Palmer

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GPU support for MPICH
by Palmer, Bruce J 27 Jan '21

27 Jan '21

Hi, I just downloaded mpich-3.4.1 and I want to try and configure and build it with GPU support. There doesn’t appear to be any documentation on how to go about this, or at least it is very well hidden. Can you tell me where to find information? Bruce Palmer

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Re: [mpich-discuss] Is it okay to remove F77 support?
by Zhou, Hui 27 Jan '21

27 Jan '21

Sorry for my original confusing subject, but I think I like the disturbance it raised and we are getting clarifications as we discuss. There are two separate aspects, what means to MPI application/users and what means to build MPICH. My question was aimed at the latter aspect, but I think we should address the first aspect as well. For the application code, it only concerns with two points (correct me if I am off) * INCLUDE ‘mpif.h’ * The compiler will be able to link to `-lmpifort` None of these two will change. `mpif.h` in MPICH, which just defines constants, will not use any syntax beyond what – lack of better terms, `g77` -- would accept. As for the linking, as long as the same or compatible Fortran compiler is used as the one used to build MPICH, the linking is guaranteed by the compiler. Shout, if the above miss anything from an application/legacy code point of view. The second aspect is all about building MPICH. The interest is to drop support for any non-common Fortran compilers that some system may use. You use F77 doesn’t mean we have to use F77 as long as we support you keep using F77 😊. If we assume all Fortran compilers that our users will use are able to build code with Fortran 90 at least, then we can simply take the assumptions of Fortran 90 and remove some of the legacy detection and work-around measures, merge our *internal* Fortran support and potentially offer a more robust Fortran support . -- Hui Zhou From: Gus Correa via discuss <discuss(a)mpich.org> Date: Wednesday, January 27, 2021 at 10:55 AM To: MPICH-Discuss <discuss(a)mpich.org> Cc: Gus Correa <gus(a)ldeo.columbia.edu> Subject: Re: [mpich-discuss] Is it okay to remove F77 support? On Wed, Jan 27, 2021 at 9:45 AM Raffenetti, Kenneth J. <raffenet(a)mcs.anl.gov<mailto:[email protected]>> wrote: On 1/26/21, 9:10 PM, "Gus Correa via discuss" <discuss(a)mpich.org<mailto:[email protected]>> wrote: Is it okay to remove F77 support? No, NO, NO!!!! NO! Removing the support to Fortran 77 from MPI is a disastrous idea! Sorry to say, but it is really stupid to suppose that only because compilers support F90 that you can remove F77 support from MPI. A lot of people, academic institutions, and probably industry, continue to use, and develop new code in F77. What matters is if the CODE is written in Fortran 90 or in Fortran 77, and whether it uses the Fortran 77 MPI API or the Fortran 90 MPI API, not whether the compiler supports Fortran 90 (and yes, if not all, do). There is an enormous Fortran 77 code base, written using MPI, and that is not likely to change for the foreseeable future. That is true in the Atmospheric/Climate/Ocean sciences, where I work, but would guess this is true in other areas of science as well. Just one example: The MITgcm, which has an huge community of users, is the backbone for many research projects, supports many PhD thesis, is 100% written in Fortran-77 and will not be changed anytime soon, as there is no financial support to do that. Also, this type of inquiry to the MPICH community is way too narrow. I don't think you should be using emails on a mailing list to base such a consequential decision. Argonne should know better which community it supports, which codes out there use MPI. I think there is some misunderstanding of the question here. The MPICH team is asking if it would be OK to drop support for building MPICH with an F77 only compiler. MPICH will still support all standard Fortran language bindings: mpif.h, use mpi, and use mpi_f08. Does the code you speak of not build with modern Fortran compilers? If so, that is the kind of feedback we are looking for. Thanks, Ken Well, then the question was very poorly formulated. It suggests suppressing the Mpich Fortran-77 API. Hard to gauge the impact of removing support of F77 compiler (ONLY), but it may cause trouble when building complex code, and linking it to MPI (mpich), as some may actually require a compiler that is specific for Fortran-77, or have Makefiles and other utilities that rely on such a compiler. Gus Correa

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Re: [mpich-discuss] Is it okay to remove F77 support?
by Jeff Hammond 27 Jan '21

27 Jan '21

Squyres' point is that there is not and has never been an MPI Fortran 77 API and every time someone implies there is, it confuses people. mpif.h requires ISO Fortran 90 - it just happens to support fixed-source form and does not require any of the Fortran 90 features that were not ubiquitous in compilers ~15 years ago. The original question was correct, but could not be interpreted correctly by most people. It asked whether MPICH could drop support for compilers that support no Fortran dialect beyond Fortran 77. The only compiler I have ever used that would be impacted by this is g77, which I used in the same era that I used Itanium. Jeff > Well, then the question was very poorly formulated. > It suggests suppressing the Mpich Fortran-77 API. > > Hard to gauge the impact of removing support of F77 compiler (ONLY), > but it may cause trouble when building complex code, > and linking it to MPI (mpich), > as some may actually require a compiler that is specific for Fortran-77, > or have Makefiles and other utilities that rely on such a compiler. > > Gus Correa > _______________________________________________ > discuss mailing list discuss(a)mpich.org > To manage subscription options or unsubscribe: > https://lists.mpich.org/mailman/listinfo/discuss > -- Jeff Hammond jeff.science(a)gmail.com http://jeffhammond.github.io/

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