Requirement on METIS int size

[ivan-pi]

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]

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 notifications@github.com 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 https://github.com/sfilippone/psblas3/issues/13, or unsubscribe https://github.com/notifications/unsubscribe-auth/AD274TZKBDXNMZEZQK7BIN3SY4LHNANCNFSM4V2RGPWQ .

[sfilippone]

(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 notifications@github.com 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 https://github.com/sfilippone/psblas3/issues/13, or unsubscribe https://github.com/notifications/unsubscribe-auth/AD274TZKBDXNMZEZQK7BIN3SY4LHNANCNFSM4V2RGPWQ .

[sfilippone]

The new release 3.7.0 has improved support for both 32 and 64 bit versions of METIS.