Requirement on METIS int size
ivan-pi opened this issue · 3 comments
ivan-pi commented
Hello @sfilippone,
I would like to use PSBLAS for an unstructured lattice Boltzmann code (I've seen it used this way in some of your slides).
Running the configure script with ./configure --with-metis=-lmetis I can see the following:
checking metis.h usability... yes
checking metis.h presence... yes
checking for metis.h... yes
checking for METIS integer size... 32
checking for METIS real size... 32
checking for METIS_PartGraphKway in -lmetis ... yes
checking for METIS_SetDefaultOptions in -lmetis -lm ... yes
however, the final configuration says:
METIS usable : no
METIS bitsize : 32
METIS realsize : 32
I installed METIS using the apt command on Linux. From previous experimentation with METIS I know it can be compiled also with 64-bit integers in reals.
Would this solve my issue?
Ivan
sfilippone commented
Yes, it would solve your problem. The reason why the script says that METIS
is not usable is that METIS is used on matrices holding GLOBAL indice, i.e.
in PSBLAS jargon they are PSB_LxSPMAT_TYPE and the default configure sets
Lx to use 8-byte integers; so, using the 64-bits version of METIS should
solve the problem.
If it doesn't work, let me know
Cheers
S.
…On Fri, Jan 8, 2021 at 3:47 PM Ivan Pribec ***@***.***> wrote:
Hello @sfilippone <https://github.com/sfilippone>,
I would like to use PSBLAS for an unstructured lattice Boltzmann code
(I've seen it used this way in some of your slides).
Running the configure script with ./configure --with-metis=-lmetis I can
see the following:
checking metis.h usability... yes
checking metis.h presence... yes
checking for metis.h... yes
checking for METIS integer size... 32
checking for METIS real size... 32
checking for METIS_PartGraphKway in -lmetis ... yes
checking for METIS_SetDefaultOptions in -lmetis -lm ... yes
however, the final configuration says:
METIS usable : no
METIS bitsize : 32
METIS realsize : 32
I installed METIS using the apt command on Linux. From previous
experimentation <https://github.com/ivan-pi/fmetis> with METIS I know it
can be compiled also with 64-bit integers in reals.
Would this solve my issue?
Ivan
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sfilippone commented
(a cheap alternative would be to configure --with-lpk=4 to use 4-bytes
integers on global indices; but then, of course you cannot have a global
index space with more than 2G indices)
On Fri, Jan 8, 2021 at 4:46 PM Salvatore Filippone <
filippone.salvatore@gmail.com> wrote:
… Yes, it would solve your problem. The reason why the script says that
METIS is not usable is that METIS is used on matrices holding GLOBAL
indice, i.e. in PSBLAS jargon they are PSB_LxSPMAT_TYPE and the default
configure sets Lx to use 8-byte integers; so, using the 64-bits version of
METIS should solve the problem.
If it doesn't work, let me know
Cheers
S.
On Fri, Jan 8, 2021 at 3:47 PM Ivan Pribec ***@***.***>
wrote:
> Hello @sfilippone <https://github.com/sfilippone>,
>
> I would like to use PSBLAS for an unstructured lattice Boltzmann code
> (I've seen it used this way in some of your slides).
>
> Running the configure script with ./configure --with-metis=-lmetis I can
> see the following:
>
> checking metis.h usability... yes
> checking metis.h presence... yes
> checking for metis.h... yes
> checking for METIS integer size... 32
> checking for METIS real size... 32
> checking for METIS_PartGraphKway in -lmetis ... yes
> checking for METIS_SetDefaultOptions in -lmetis -lm ... yes
>
> however, the final configuration says:
>
> METIS usable : no
> METIS bitsize : 32
> METIS realsize : 32
>
> I installed METIS using the apt command on Linux. From previous
> experimentation <https://github.com/ivan-pi/fmetis> with METIS I know it
> can be compiled also with 64-bit integers in reals.
>
> Would this solve my issue?
>
> Ivan
>
> —
> You are receiving this because you were mentioned.
> Reply to this email directly, view it on GitHub
> <#13>, or unsubscribe
> <https://github.com/notifications/unsubscribe-auth/AD274TZKBDXNMZEZQK7BIN3SY4LHNANCNFSM4V2RGPWQ>
> .
>
sfilippone commented
The new release 3.7.0 has improved support for both 32 and 64 bit versions of METIS.