March 2008 - mpiwg-rma - mailman3.cels.anl.gov

Re: [Mpi3-rma] MPI RMW operations
by Shipman, Galen M. 27 Mar '08

27 Mar '08

Rajeev, On Mar 27, 2008, at 6:05 PM, Rajeev Thakur wrote: > Some comments: > > * Are the semantics supposed to be that the original value at the > target is > read and stored at the result_addr on the origin (like a Get), and the > target memory is updated with the result of the reduction operation > (like > Accumulate)? Exactly, the value prior to the update is "returned" in the result_addr and the target memory is updated with the result of the operation. > > * What are the semantics of the two-operand versions? > For MPI_RMW2_COMP_SWAP: operand_addr is the comparand, operand2_addr is the operand. Comparand is compared to the value at the target, if these values are equal then operand is written to the value at the target. For MPI_RMW2_MASK_SWAP: operand_addr is the maskarand, operand2_addr is the operand. Maskarand identifies the bits within the value at the target to be updated with the corresponding bits from operand. > * Why is there no count, datatype at the target like in Accumulate? This is intentional, datatypes and count must match on passive and active sides and are therefore implicit. > > * When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT, what is the lock > type for > the Win_lock -- shared or exclusive? As all MPI_RMW/2 operations have the potential of updating the remote value and may therefore cause conflicts I would expect this to be an MPI_LOCK_EXCLUSIVE > Also, Win_unlock takes only two > parameters. > Yes, the example needs to be corrected. Thanks for the comments, Galen > * Regarding the interaction with explicit epochs of Rmw when assert == > MPI_MODE_PASSIVE_EPOCH_IMPLICIT, it should be the same as the > interaction of > its equivalent sequence, namely, Lock - Rmw - Unlock. In other > words, there > shouldn't be another epoch around it on the same process (nested > epochs not > allowed), and the epochs on other processes must not conflict. > > Rajeev > > >> -----Original Message----- >> From: mpi3-rma-bounces(a)lists.mpi-forum.org >> [mailto:[email protected]] On Behalf Of >> Shipman, Galen M. >> Sent: Monday, March 24, 2008 10:10 PM >> To: mpi3-rma(a)lists.mpi-forum.org >> Subject: [Mpi3-rma] MPI RMW operations >> >> >> Howard and I have been working on the RMW operations listed >> below for >> consideration. >> >> - Galen Shipman - ORNL >> >> >> Single operand RMW operations >> >> MPI_Rmw(void *operand_addr, >> int count, >> MPI_Datatype datatype, >> void *result_addr, >> int target_rank, >> MPI_Aint target_disp, >> int assert, >> MPI_RMW_Op op, >> MPI_Win win) >> >> >> Two operand RMW operations >> >> MPI_Rmw2(void *operand_addr, >> int count, >> MPI_Datatype datatype, >> void *operand2_addr, >> void *result_addr, >> int target_rank, >> MPI_Aint target_disp, >> int assert, >> MPI_RMW_2_Op op, >> MPI_Win win) >> >> >> >> MPI_RMW_Op Predefined RMW single operand operations >> The following predefined operations are supplied for MPI_RMW >> and related >> functions. These operations are invoked by placing the >> following in op. >> >> Name Meaning >> >> MPI_RMW_INC increment >> MPI_RMW_PROD product >> MPI_RMW_SUM sum >> MPI_RMW_LAND logical and >> MPI_RMW_LOR logical or >> MPI_RMW_LXOR logical xor >> MPI_RMW_BAND binary and >> MPI_RMW_BOR binary or >> MPI_RMW_BXOR binary xor >> MPI_RMW_SWAP swap value >> >> MPI_RMW_2_Op Predefined RMW two operand operations >> >> Name Meaning >> >> MPI_RMW2_MASK_SWAP swap masked bits >> MPI_RMW2_COMP_SWAP compare and swap >> >> Note: MPI_RMW2_COMP_SWAP is an equality comparison, we may wish to >> consider multiple comparison operations such as >, >=, <, <=, ==, <>. >> >> Both MPI_Rmw and MPI_Rmw2 take an assert argument. >> When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT MPI_Rmw/2 is >> equivalent to: >> >> MPI_Win_lock(target_rank,0,win); >> MPI_Rmw(.....); >> MPI_Win_unlock(target_rank,0,win); >> >> When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT | MPI_MODE_NOCHECK >> the MPI library knows that the window lock at the target need not be >> acquired. >> >> >> >> >> _______________________________________________ >> mpi3-rma mailing list >> mpi3-rma(a)lists.mpi-forum.org >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma >> >> > > _______________________________________________ > mpi3-rma mailing list > mpi3-rma(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma

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Re: [Mpi3-rma] MPI RMW operations
by Rajeev Thakur 27 Mar '08

27 Mar '08

Some comments: * Are the semantics supposed to be that the original value at the target is read and stored at the result_addr on the origin (like a Get), and the target memory is updated with the result of the reduction operation (like Accumulate)? * What are the semantics of the two-operand versions? * Why is there no count, datatype at the target like in Accumulate? * When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT, what is the lock type for the Win_lock -- shared or exclusive? Also, Win_unlock takes only two parameters. * Regarding the interaction with explicit epochs of Rmw when assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT, it should be the same as the interaction of its equivalent sequence, namely, Lock - Rmw - Unlock. In other words, there shouldn't be another epoch around it on the same process (nested epochs not allowed), and the epochs on other processes must not conflict. Rajeev > -----Original Message----- > From: mpi3-rma-bounces(a)lists.mpi-forum.org > [mailto:[email protected]] On Behalf Of > Shipman, Galen M. > Sent: Monday, March 24, 2008 10:10 PM > To: mpi3-rma(a)lists.mpi-forum.org > Subject: [Mpi3-rma] MPI RMW operations > > > Howard and I have been working on the RMW operations listed > below for > consideration. > > - Galen Shipman - ORNL > > > Single operand RMW operations > > MPI_Rmw(void *operand_addr, > int count, > MPI_Datatype datatype, > void *result_addr, > int target_rank, > MPI_Aint target_disp, > int assert, > MPI_RMW_Op op, > MPI_Win win) > > > Two operand RMW operations > > MPI_Rmw2(void *operand_addr, > int count, > MPI_Datatype datatype, > void *operand2_addr, > void *result_addr, > int target_rank, > MPI_Aint target_disp, > int assert, > MPI_RMW_2_Op op, > MPI_Win win) > > > > MPI_RMW_Op Predefined RMW single operand operations > The following predefined operations are supplied for MPI_RMW > and related > functions. These operations are invoked by placing the > following in op. > > Name Meaning > > MPI_RMW_INC increment > MPI_RMW_PROD product > MPI_RMW_SUM sum > MPI_RMW_LAND logical and > MPI_RMW_LOR logical or > MPI_RMW_LXOR logical xor > MPI_RMW_BAND binary and > MPI_RMW_BOR binary or > MPI_RMW_BXOR binary xor > MPI_RMW_SWAP swap value > > MPI_RMW_2_Op Predefined RMW two operand operations > > Name Meaning > > MPI_RMW2_MASK_SWAP swap masked bits > MPI_RMW2_COMP_SWAP compare and swap > > Note: MPI_RMW2_COMP_SWAP is an equality comparison, we may wish to > consider multiple comparison operations such as >, >=, <, <=, ==, <>. > > Both MPI_Rmw and MPI_Rmw2 take an assert argument. > When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT MPI_Rmw/2 is > equivalent to: > > MPI_Win_lock(target_rank,0,win); > MPI_Rmw(.....); > MPI_Win_unlock(target_rank,0,win); > > When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT | MPI_MODE_NOCHECK > the MPI library knows that the window lock at the target need not be > acquired. > > > > > _______________________________________________ > mpi3-rma mailing list > mpi3-rma(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma > >

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Re: [Mpi3-rma] MPI RMW operations
by Shipman, Galen M. 25 Mar '08

25 Mar '08

HI Brian, On Mar 25, 2008, at 11:22 AM, Brian W. Barrett wrote: > That makes sense. How would an MPI_Rmw() call with the IMPLICIT > epoch interact with explicit epochs? If the answer is "it wouldn't", > I think that's valid. We just need to state it. I would think the behavior would be undefined or "it wouldn't". > > Also, is there any reason we're not using the standard OP defines? > We would need additional operations for RMW/2 (as shown) and restrict other operations that don't apply within the standard. I would also want to carefully look at the implementation costs for using the standard OP defines. - Galen > Brian > > On Mar 25, 2008, at 9:14 AM, Howard Pritchard wrote: > >> Hello Brian, >> >> That was the idea. >> >> The problem as we saw it is that in non-mpi shared memory >> applications, atomic memory operations are typically used for >> lightweight >> synchronization. Having to always use potentially heavyweight lock/ >> unlock >> sequences seems to defeat the purpose of adding rmw operations to the >> mpi specification. >> >> This is a special case of the more general discussion that we should >> have about global visibility of rma operations, etc. >> >> Howard >> >> Brian W. Barrett wrote: >> >>> If MPI_MODE_PASSIVE_EPOCH_IMPLICIT is not given, is synchronization >>> explicit using the standard epoch functions? >>> >>> Brian >>> >>> On Mar 24, 2008, at 9:09 PM, Shipman, Galen M. wrote: >>> >>> >>> >>>> Howard and I have been working on the RMW operations listed below >>>> for >>>> consideration. >>>> >>>> - Galen Shipman - ORNL >>>> >>>> >>>> Single operand RMW operations >>>> >>>> MPI_Rmw(void *operand_addr, >>>> int count, >>>> MPI_Datatype datatype, >>>> void *result_addr, >>>> int target_rank, >>>> MPI_Aint target_disp, >>>> int assert, >>>> MPI_RMW_Op op, >>>> MPI_Win win) >>>> >>>> >>>> Two operand RMW operations >>>> >>>> MPI_Rmw2(void *operand_addr, >>>> int count, >>>> MPI_Datatype datatype, >>>> void *operand2_addr, >>>> void *result_addr, >>>> int target_rank, >>>> MPI_Aint target_disp, >>>> int assert, >>>> MPI_RMW_2_Op op, >>>> MPI_Win win) >>>> >>>> >>>> >>>> MPI_RMW_Op Predefined RMW single operand operations >>>> The following predefined operations are supplied for MPI_RMW and >>>> related >>>> functions. These operations are invoked by placing the following >>>> in op. >>>> >>>> Name Meaning >>>> >>>> MPI_RMW_INC increment >>>> MPI_RMW_PROD product >>>> MPI_RMW_SUM sum >>>> MPI_RMW_LAND logical and >>>> MPI_RMW_LOR logical or >>>> MPI_RMW_LXOR logical xor >>>> MPI_RMW_BAND binary and >>>> MPI_RMW_BOR binary or >>>> MPI_RMW_BXOR binary xor >>>> MPI_RMW_SWAP swap value >>>> >>>> MPI_RMW_2_Op Predefined RMW two operand operations >>>> >>>> Name Meaning >>>> >>>> MPI_RMW2_MASK_SWAP swap masked bits >>>> MPI_RMW2_COMP_SWAP compare and swap >>>> >>>> Note: MPI_RMW2_COMP_SWAP is an equality comparison, we may wish to >>>> consider multiple comparison operations such as >, >=, <, <=, ==, >>>> <>. >>>> >>>> Both MPI_Rmw and MPI_Rmw2 take an assert argument. >>>> When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT MPI_Rmw/2 is >>>> equivalent to: >>>> >>>> MPI_Win_lock(target_rank,0,win); >>>> MPI_Rmw(.....); >>>> MPI_Win_unlock(target_rank,0,win); >>>> >>>> When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT | MPI_MODE_NOCHECK >>>> the MPI library knows that the window lock at the target need >>>> not be >>>> acquired. >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> mpi3-rma mailing list >>>> mpi3-rma(a)lists.mpi-forum.org >>>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma >>>> >>>> >>>> >>> >>> >>> >> >> >> -- >> >> Howard Pritchard >> Cray Inc. >> >> >> _______________________________________________ >> mpi3-rma mailing list >> mpi3-rma(a)lists.mpi-forum.org >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma >> > > -- > Brian W. Barrett > Dept. 1422: Scalable Computer Architectures > Sandia National Laboratories > > > > > _______________________________________________ > mpi3-rma mailing list > mpi3-rma(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma

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Re: [Mpi3-rma] MPI RMW operations
by Howard Pritchard 25 Mar '08

25 Mar '08

Hello Brian, Brian W. Barrett wrote: >That makes sense. How would an MPI_Rmw() call with the IMPLICIT >epoch interact with explicit epochs? If the answer is "it wouldn't", >I think that's valid. We just need to state it. > > This is a good point. Given the way it is illegal to have an 'epoch within an epoch' currently, I think this should continue to be enforced. So I would prefer the "it wouldn't", otherwise we risk making rma epoch semantics more complicated. >Also, is there any reason we're not using the standard OP defines? > > We could use the standard ones for the non-fetching operations. For fetching operations we could re-use them as long as it was clearly defined what was returned to the initiator in 'result_addr'. Some new operations would have to be added for compare and swap and masked compare and swap though. Howard >Brian > >On Mar 25, 2008, at 9:14 AM, Howard Pritchard wrote: > > > >>Hello Brian, >> >>That was the idea. >> >>The problem as we saw it is that in non-mpi shared memory >>applications, atomic memory operations are typically used for >>lightweight >>synchronization. Having to always use potentially heavyweight lock/ >>unlock >>sequences seems to defeat the purpose of adding rmw operations to the >>mpi specification. >> >>This is a special case of the more general discussion that we should >>have about global visibility of rma operations, etc. >> >>Howard >> >>Brian W. Barrett wrote: >> >> >> >>>If MPI_MODE_PASSIVE_EPOCH_IMPLICIT is not given, is synchronization >>>explicit using the standard epoch functions? >>> >>>Brian >>> >>>On Mar 24, 2008, at 9:09 PM, Shipman, Galen M. wrote: >>> >>> >>> >>> >>> >>>>Howard and I have been working on the RMW operations listed below >>>>for >>>>consideration. >>>> >>>>- Galen Shipman - ORNL >>>> >>>> >>>>Single operand RMW operations >>>> >>>>MPI_Rmw(void *operand_addr, >>>> int count, >>>> MPI_Datatype datatype, >>>> void *result_addr, >>>> int target_rank, >>>> MPI_Aint target_disp, >>>> int assert, >>>> MPI_RMW_Op op, >>>> MPI_Win win) >>>> >>>> >>>>Two operand RMW operations >>>> >>>>MPI_Rmw2(void *operand_addr, >>>> int count, >>>> MPI_Datatype datatype, >>>> void *operand2_addr, >>>> void *result_addr, >>>> int target_rank, >>>> MPI_Aint target_disp, >>>> int assert, >>>> MPI_RMW_2_Op op, >>>> MPI_Win win) >>>> >>>> >>>> >>>>MPI_RMW_Op Predefined RMW single operand operations >>>>The following predefined operations are supplied for MPI_RMW and >>>>related >>>>functions. These operations are invoked by placing the following >>>>in op. >>>> >>>>Name Meaning >>>> >>>>MPI_RMW_INC increment >>>>MPI_RMW_PROD product >>>>MPI_RMW_SUM sum >>>>MPI_RMW_LAND logical and >>>>MPI_RMW_LOR logical or >>>>MPI_RMW_LXOR logical xor >>>>MPI_RMW_BAND binary and >>>>MPI_RMW_BOR binary or >>>>MPI_RMW_BXOR binary xor >>>>MPI_RMW_SWAP swap value >>>> >>>>MPI_RMW_2_Op Predefined RMW two operand operations >>>> >>>>Name Meaning >>>> >>>>MPI_RMW2_MASK_SWAP swap masked bits >>>>MPI_RMW2_COMP_SWAP compare and swap >>>> >>>>Note: MPI_RMW2_COMP_SWAP is an equality comparison, we may wish to >>>>consider multiple comparison operations such as >, >=, <, <=, ==, >>>><>. >>>> >>>>Both MPI_Rmw and MPI_Rmw2 take an assert argument. >>>>When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT MPI_Rmw/2 is >>>>equivalent to: >>>> >>>>MPI_Win_lock(target_rank,0,win); >>>>MPI_Rmw(.....); >>>>MPI_Win_unlock(target_rank,0,win); >>>> >>>>When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT | MPI_MODE_NOCHECK >>>>the MPI library knows that the window lock at the target need not be >>>>acquired. >>>> >>>> >>>> >>>> >>>>_______________________________________________ >>>>mpi3-rma mailing list >>>>mpi3-rma(a)lists.mpi-forum.org >>>>http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma >>>> >>>> >>>> >>>> >>>> >>> >>> >>> >>-- >> >>Howard Pritchard >>Cray Inc. >> >> >>_______________________________________________ >>mpi3-rma mailing list >>mpi3-rma(a)lists.mpi-forum.org >>http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma >> >> >> > > > -- Howard Pritchard Cray Inc.

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Re: [Mpi3-rma] MPI RMW operations
by Brian W. Barrett 25 Mar '08

25 Mar '08

That makes sense. How would an MPI_Rmw() call with the IMPLICIT epoch interact with explicit epochs? If the answer is "it wouldn't", I think that's valid. We just need to state it. Also, is there any reason we're not using the standard OP defines? Brian On Mar 25, 2008, at 9:14 AM, Howard Pritchard wrote: > Hello Brian, > > That was the idea. > > The problem as we saw it is that in non-mpi shared memory > applications, atomic memory operations are typically used for > lightweight > synchronization. Having to always use potentially heavyweight lock/ > unlock > sequences seems to defeat the purpose of adding rmw operations to the > mpi specification. > > This is a special case of the more general discussion that we should > have about global visibility of rma operations, etc. > > Howard > > Brian W. Barrett wrote: > >> If MPI_MODE_PASSIVE_EPOCH_IMPLICIT is not given, is synchronization >> explicit using the standard epoch functions? >> >> Brian >> >> On Mar 24, 2008, at 9:09 PM, Shipman, Galen M. wrote: >> >> >> >>> Howard and I have been working on the RMW operations listed below >>> for >>> consideration. >>> >>> - Galen Shipman - ORNL >>> >>> >>> Single operand RMW operations >>> >>> MPI_Rmw(void *operand_addr, >>> int count, >>> MPI_Datatype datatype, >>> void *result_addr, >>> int target_rank, >>> MPI_Aint target_disp, >>> int assert, >>> MPI_RMW_Op op, >>> MPI_Win win) >>> >>> >>> Two operand RMW operations >>> >>> MPI_Rmw2(void *operand_addr, >>> int count, >>> MPI_Datatype datatype, >>> void *operand2_addr, >>> void *result_addr, >>> int target_rank, >>> MPI_Aint target_disp, >>> int assert, >>> MPI_RMW_2_Op op, >>> MPI_Win win) >>> >>> >>> >>> MPI_RMW_Op Predefined RMW single operand operations >>> The following predefined operations are supplied for MPI_RMW and >>> related >>> functions. These operations are invoked by placing the following >>> in op. >>> >>> Name Meaning >>> >>> MPI_RMW_INC increment >>> MPI_RMW_PROD product >>> MPI_RMW_SUM sum >>> MPI_RMW_LAND logical and >>> MPI_RMW_LOR logical or >>> MPI_RMW_LXOR logical xor >>> MPI_RMW_BAND binary and >>> MPI_RMW_BOR binary or >>> MPI_RMW_BXOR binary xor >>> MPI_RMW_SWAP swap value >>> >>> MPI_RMW_2_Op Predefined RMW two operand operations >>> >>> Name Meaning >>> >>> MPI_RMW2_MASK_SWAP swap masked bits >>> MPI_RMW2_COMP_SWAP compare and swap >>> >>> Note: MPI_RMW2_COMP_SWAP is an equality comparison, we may wish to >>> consider multiple comparison operations such as >, >=, <, <=, ==, >>> <>. >>> >>> Both MPI_Rmw and MPI_Rmw2 take an assert argument. >>> When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT MPI_Rmw/2 is >>> equivalent to: >>> >>> MPI_Win_lock(target_rank,0,win); >>> MPI_Rmw(.....); >>> MPI_Win_unlock(target_rank,0,win); >>> >>> When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT | MPI_MODE_NOCHECK >>> the MPI library knows that the window lock at the target need not be >>> acquired. >>> >>> >>> >>> >>> _______________________________________________ >>> mpi3-rma mailing list >>> mpi3-rma(a)lists.mpi-forum.org >>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma >>> >>> >>> >> >> >> > > > -- > > Howard Pritchard > Cray Inc. > > > _______________________________________________ > mpi3-rma mailing list > mpi3-rma(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma > -- Brian W. Barrett Dept. 1422: Scalable Computer Architectures Sandia National Laboratories

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Re: [Mpi3-rma] MPI RMW operations
by Howard Pritchard 25 Mar '08

25 Mar '08

Hello Brian, That was the idea. The problem as we saw it is that in non-mpi shared memory applications, atomic memory operations are typically used for lightweight synchronization. Having to always use potentially heavyweight lock/unlock sequences seems to defeat the purpose of adding rmw operations to the mpi specification. This is a special case of the more general discussion that we should have about global visibility of rma operations, etc. Howard Brian W. Barrett wrote: >If MPI_MODE_PASSIVE_EPOCH_IMPLICIT is not given, is synchronization >explicit using the standard epoch functions? > >Brian > >On Mar 24, 2008, at 9:09 PM, Shipman, Galen M. wrote: > > > >>Howard and I have been working on the RMW operations listed below for >>consideration. >> >>- Galen Shipman - ORNL >> >> >>Single operand RMW operations >> >>MPI_Rmw(void *operand_addr, >> int count, >> MPI_Datatype datatype, >> void *result_addr, >> int target_rank, >> MPI_Aint target_disp, >> int assert, >> MPI_RMW_Op op, >> MPI_Win win) >> >> >>Two operand RMW operations >> >>MPI_Rmw2(void *operand_addr, >> int count, >> MPI_Datatype datatype, >> void *operand2_addr, >> void *result_addr, >> int target_rank, >> MPI_Aint target_disp, >> int assert, >> MPI_RMW_2_Op op, >> MPI_Win win) >> >> >> >>MPI_RMW_Op Predefined RMW single operand operations >>The following predefined operations are supplied for MPI_RMW and >>related >>functions. These operations are invoked by placing the following >>in op. >> >>Name Meaning >> >>MPI_RMW_INC increment >>MPI_RMW_PROD product >>MPI_RMW_SUM sum >>MPI_RMW_LAND logical and >>MPI_RMW_LOR logical or >>MPI_RMW_LXOR logical xor >>MPI_RMW_BAND binary and >>MPI_RMW_BOR binary or >>MPI_RMW_BXOR binary xor >>MPI_RMW_SWAP swap value >> >>MPI_RMW_2_Op Predefined RMW two operand operations >> >>Name Meaning >> >>MPI_RMW2_MASK_SWAP swap masked bits >>MPI_RMW2_COMP_SWAP compare and swap >> >>Note: MPI_RMW2_COMP_SWAP is an equality comparison, we may wish to >>consider multiple comparison operations such as >, >=, <, <=, ==, <>. >> >>Both MPI_Rmw and MPI_Rmw2 take an assert argument. >>When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT MPI_Rmw/2 is >>equivalent to: >> >>MPI_Win_lock(target_rank,0,win); >>MPI_Rmw(.....); >>MPI_Win_unlock(target_rank,0,win); >> >>When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT | MPI_MODE_NOCHECK >>the MPI library knows that the window lock at the target need not be >>acquired. >> >> >> >> >>_______________________________________________ >>mpi3-rma mailing list >>mpi3-rma(a)lists.mpi-forum.org >>http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma >> >> >> > > > -- Howard Pritchard Cray Inc.

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Re: [Mpi3-rma] MPI RMW operations
by Brian W. Barrett 25 Mar '08

25 Mar '08

If MPI_MODE_PASSIVE_EPOCH_IMPLICIT is not given, is synchronization explicit using the standard epoch functions? Brian On Mar 24, 2008, at 9:09 PM, Shipman, Galen M. wrote: > > Howard and I have been working on the RMW operations listed below for > consideration. > > - Galen Shipman - ORNL > > > Single operand RMW operations > > MPI_Rmw(void *operand_addr, > int count, > MPI_Datatype datatype, > void *result_addr, > int target_rank, > MPI_Aint target_disp, > int assert, > MPI_RMW_Op op, > MPI_Win win) > > > Two operand RMW operations > > MPI_Rmw2(void *operand_addr, > int count, > MPI_Datatype datatype, > void *operand2_addr, > void *result_addr, > int target_rank, > MPI_Aint target_disp, > int assert, > MPI_RMW_2_Op op, > MPI_Win win) > > > > MPI_RMW_Op Predefined RMW single operand operations > The following predefined operations are supplied for MPI_RMW and > related > functions. These operations are invoked by placing the following > in op. > > Name Meaning > > MPI_RMW_INC increment > MPI_RMW_PROD product > MPI_RMW_SUM sum > MPI_RMW_LAND logical and > MPI_RMW_LOR logical or > MPI_RMW_LXOR logical xor > MPI_RMW_BAND binary and > MPI_RMW_BOR binary or > MPI_RMW_BXOR binary xor > MPI_RMW_SWAP swap value > > MPI_RMW_2_Op Predefined RMW two operand operations > > Name Meaning > > MPI_RMW2_MASK_SWAP swap masked bits > MPI_RMW2_COMP_SWAP compare and swap > > Note: MPI_RMW2_COMP_SWAP is an equality comparison, we may wish to > consider multiple comparison operations such as >, >=, <, <=, ==, <>. > > Both MPI_Rmw and MPI_Rmw2 take an assert argument. > When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT MPI_Rmw/2 is > equivalent to: > > MPI_Win_lock(target_rank,0,win); > MPI_Rmw(.....); > MPI_Win_unlock(target_rank,0,win); > > When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT | MPI_MODE_NOCHECK > the MPI library knows that the window lock at the target need not be > acquired. > > > > > _______________________________________________ > mpi3-rma mailing list > mpi3-rma(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma > -- Brian W. Barrett Dept. 1422: Scalable Computer Architectures Sandia National Laboratories

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[Mpi3-rma] MPI RMW operations
by Shipman, Galen M. 24 Mar '08

24 Mar '08

Howard and I have been working on the RMW operations listed below for consideration. - Galen Shipman - ORNL Single operand RMW operations MPI_Rmw(void *operand_addr, int count, MPI_Datatype datatype, void *result_addr, int target_rank, MPI_Aint target_disp, int assert, MPI_RMW_Op op, MPI_Win win) Two operand RMW operations MPI_Rmw2(void *operand_addr, int count, MPI_Datatype datatype, void *operand2_addr, void *result_addr, int target_rank, MPI_Aint target_disp, int assert, MPI_RMW_2_Op op, MPI_Win win) MPI_RMW_Op Predefined RMW single operand operations The following predefined operations are supplied for MPI_RMW and related functions. These operations are invoked by placing the following in op. Name Meaning MPI_RMW_INC increment MPI_RMW_PROD product MPI_RMW_SUM sum MPI_RMW_LAND logical and MPI_RMW_LOR logical or MPI_RMW_LXOR logical xor MPI_RMW_BAND binary and MPI_RMW_BOR binary or MPI_RMW_BXOR binary xor MPI_RMW_SWAP swap value MPI_RMW_2_Op Predefined RMW two operand operations Name Meaning MPI_RMW2_MASK_SWAP swap masked bits MPI_RMW2_COMP_SWAP compare and swap Note: MPI_RMW2_COMP_SWAP is an equality comparison, we may wish to consider multiple comparison operations such as >, >=, <, <=, ==, <>. Both MPI_Rmw and MPI_Rmw2 take an assert argument. When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT MPI_Rmw/2 is equivalent to: MPI_Win_lock(target_rank,0,win); MPI_Rmw(.....); MPI_Win_unlock(target_rank,0,win); When assert == MPI_MODE_PASSIVE_EPOCH_IMPLICIT | MPI_MODE_NOCHECK the MPI library knows that the window lock at the target need not be acquired.

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