[petsc-users] 3.16.4 amd blis libflame linking problem

[Satish Balay]

On Fri, 4 Feb 2022, Barry Smith wrote:

> 
> 
> > On Feb 4, 2022, at 12:38 PM, Satish Balay <balay at mcs.anl.gov> wrote:
> > 
> > On Fri, 4 Feb 2022, Barry Smith wrote:
> > 
> >> 
> >> 
> >>> On Feb 4, 2022, at 12:27 PM, Satish Balay <balay at mcs.anl.gov> wrote:
> >>> 
> >>> Probably best if you can use the same version of gfortran to build both petsc and libflame/blis
> >>> 
> >>>> /usr/bin/ld: warning: libgfortran.so.5, needed by /opt/amd/amd-libflame-3.1.0/lib/lp64/libflame.so, not found (try using -rpath or -rpath-link):
> >>> 
> >>> This is probably an ignore-able warning - but configure defaults to -Werror mode here.
> >> 
> >>  Hmm, if it needs libgfortran.so.5 then it needs it and it cannot be ignored since a link cannot succeed. Flame presumably contains a lot of old Fortran code from Lapack so would normally need the fortran libraries.
> > 
> > Its a warning not an error.
> > 
> > And we already have a list of excludes (of such warnings) to ignore in configure
> 
>   I understand it is a warning. But I am questioning how one could actually use this libflame library if one of its dependencies cannot be found.

libgfortran.so.4 [or .6?] might be found and used.

Yeah - ideally that should be an error - but the compiler flags it as warning not an error. [and I don't think configure should convert these warnings to errors - even thought things might break for the user - at a later stage - due to this discrepancy..]

Satish

> 
> 
> > 
> > Satish
> > 
> >> 
> >>> 
> >>> Wrt forcing link with static libraries - you can try:
> >>> 
> >>> LIBS="/opt/amd/amd-libflame-3.1.0/lib/lp64/libflame.a /opt/amd/amd-blis-3.1.0/lib/lp64/libblis.a"
> >>> 
> >>> [instead of --with-blas-lib= --with-lapack-lib= options].
> >>> 
> >>> Satish
> >>> 
> >>> 
> >>> On Fri, 4 Feb 2022, Barry Smith wrote:
> >>> 
> >>>> 
> >>>> Please do 
> >>>> 
> >>>> ldd -O /opt/amd/amd-libflame-3.1.0/lib/lp64/libflame.so
> >>>> 
> >>>> You may need to list the gfortran library directory of libgfortran.so.5 it needs to use in LDFLAGS passed to PETSc configure 
> >>>> 
> >>>> Barry
> >>>> 
> >>>> Note: Even though you explicitly listed a static library of libflame to use our configure is goofy and loses that information and wants to link with the shared version
> >>>> 
> >>>> 
> >>>>> On Feb 4, 2022, at 12:00 PM, Anton Popov <popov at uni-mainz.de> wrote:
> >>>>> 
> >>>>> 
> >>>>> 
> >>>>> On 04.02.22 17:39, Matthew Knepley wrote:
> >>>>>> On Fri, Feb 4, 2022 at 11:35 AM Anton Popov <popov at uni-mainz.de <mailto:popov at uni-mainz.de>> wrote:
> >>>>>> Hi Satish,
> >>>>>> 
> >>>>>> I just discovered that PETSc 3.16.4 fails to link against the latest AMD 
> >>>>>> BLIS and LibFLAME libraries on a Linux box.
> >>>>>> 
> >>>>>> -------------------------------------------------------------------------------
> >>>>>> You set a value for --with-blas-lib=<lib> and --with-lapack-lib=<lib>, 
> >>>>>> but ['/opt/amd/amd-blis-3.1.0/lib/lp64/libblis.a'] and 
> >>>>>> ['/opt/amd/amd-libflame-3.1.0/lib/lp64/libflame.a'] cannot be used
> >>>>>> *******************************************************************************
> >>>>>> 
> >>>>>> My previous experience with 3.9.4 on the same system was fully 
> >>>>>> successful. Looking in the configure logs (attached) reveals small 
> >>>>>> difference in the linking compared to 3.9.4
> >>>>>> 
> >>>>>> Could you please make a guess what went wrong?
> >>>>>> 
> >>>>>> Down in the log I see:
> >>>>>> 
> >>>>>> /usr/bin/ld: warning: libgfortran.so.5, needed by /opt/amd/amd-libflame-3.1.0/lib/lp64/libflame.so, not found (try using -rpath or -rpath-link):
> >>>>> Thanks Matt, I'll try.
> >>>>> 
> >>>>>> 
> >>>>>> Did the gfortran library move or get upgraded?
> >>>>> Not at all. I have configured 3.9.4 just now to make a test, and it perfectly finds all the libraries. So there must be something that 3.16.4 does differently. 
> >>>>> 
> >>>>> Best,
> >>>>> 
> >>>>> Anton
> >>>>> 
> >>>>>> 
> >>>>>> Thanks,
> >>>>>> 
> >>>>>>    Matt
> >>>>>> 
> >>>>>> Best regards,
> >>>>>> 
> >>>>>> Anton
> >>>>>> 
> >>>>>> 
> >>>>>> -- 
> >>>>>> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> >>>>>> -- Norbert Wiener
> >>>>>> 
> >>>>>> https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
> >>>> 
> >>>> 
> >>> 
> >> 
> > 
>