KNC on Fedora 23 - will it work?

[Jiří_V_]

Hello,

my Xeon Phi 31S1P should arrive today, After I fit an appropriate cooler on it, I want to install it in a workstation running Fedora 23 (a dual E5-2630 v2 on a Supermicro X9DAi board).

Preparing for the installation, I understant that to run the Phi, I will need to install the Intel MPSS stack which seems to be officially supported only on kernels up to 3.12 (or whatever is in SLES or RHEL - 3.something in any case). Fedora 23 runs on 4.2.6. I gather the MPSS stack consits of some tools packed in RPM packages, and a kernel module which could be possibly recompiled, and that there were people on this forum who successfully installed it on Fedora 20, but I found no one mentioning kernel 4 and up.

Do you think it will possible to recompile/repack/whatever to make it work under Fedora 23? Is there anything else I might need to do besides repacking the RPMs for Fedora, and recompiling the kernel modules?

Thanks, Jiri

[Jiří_V_]

I managed to compile the mpss kernel module for kernel 4.2.6 using the attached patch. Lot of the stuff is similar to the patch here https://github.com/abusse/xeon-phi-overlay/blob/master/sys-kernel/mpss-modules/files/linux-3.18.7.patch and look pretty innocent, but there are some kernel 4.2 specifics in my patch I am not exactly sure about:

1. rcu_dereference_index_check() in host/vhost/vhost.h:
This has been completely removed in 4.2, so I replaced it with smp_load_acquire(&(dev->acked_features)) - similar to how it was done here:
http://lxr.free-electrons.com/source/arch/x86/kernel/cpu/mcheck/mce.c?v=4.1#L56 vs. http://lxr.free-electrons.com/source/arch/x86/kernel/cpu/mcheck/mce.c?v=4.2#L60

2. set_mb() in micscif/micscif_select.c:
Replaced with smp_store_mb(pwq->triggered, 0), as seen in http://www.spinics.net/lists/linux-tip-commits/msg28183.html

I won't have a chance to actually install Xeon Phi in the machine until Sunday, so I can't check whether it works now.

Do you think the modifications I made are safe? (I'm mostly worried about the rcu_dereference_index_check since I have no idea what was it supposed to do. The rest seems ok)

[Jiří_V_]

I finally got a chance to install the Xeon Phi in  my machine. The cooling solution (three 40mm Airen fans with a DIY duct, they are a bit loud though) keeps the MIC at 60C on 196W.

I added rcu_lockdep_assert to my patch. I still don't know what's that part doing. I would be glad if someone could reassure me it won't make the board burn down my office while I'm away for Christmas :-)

The rest was just following the readme.txt. Now I can log in to the MIC which I suppose means it works.