Re: libpsm2 on i386

On Sat, Jun 9, 2018 at 3:40 AM, Mehdi Dogguy <mehdi@dogguy.org> wrote:

On 2018-06-09 10:20, Mehdi Dogguy wrote:

Hi all,

libpsm2 has finally landed in unstable and eventually migrated to testing,
which is great. Support for libpsm2 has been enabled in libfabric and I've
filed a bugreport so that openmpi enables it as well.

Unfortunately, libfabric is stuck in sid for now as it needs libpsm2 on i386
to build. One could restrict the build dependency on amd64 to workaround this.
But, libpsm2's code seems to support i386 as well.

Any opinion on enabling libpsm2 build on i386?

libpsm2's README indicates: “Only the x86_64 architecture is supported.”

So while some code exists [1], upstream has no intent to support libpsm2 on i386.

libpsm2 requires Omni-Path hardware and that is only supported by Intel with Haswell or better Xeon x86_64 CPUs. Technically, Omni-Path isn't even supported with AMD CPUs, although I have heard of people having some degree of success in that area.

libpsm2 probably won't build for i386 without some modifications, as there is some assembly in there. It seems highly unlikely that such a combination would ever be used.

I hope this doesn't cause libfabric too much of a headache. Please let me know if there is anything else I can do.

I'll go ahead and fix libfabric.

[1] It also fails to build on i386 for now, unsurprisingly.

Sorry for the noise,

--
Mehdi

Brian T. Smith
System Fabric Works
Senior Technical Staff
bsmith@systemfabricworks.com
GPG Key: B3C2C7B73BA3CD7F