[dpdk-dev] [PATCH v5 0/2] Balanced allocation of hugepages
thomas at monjalon.net
Wed Jun 21 11:58:12 CEST 2017
21/06/2017 11:27, Jerin Jacob:
> -----Original Message-----
> > Date: Wed, 21 Jun 2017 10:49:14 +0200
> > From: Thomas Monjalon <thomas at monjalon.net>
> > To: Jerin Jacob <jerin.jacob at caviumnetworks.com>
> > Cc: Sergio Gonzalez Monroy <sergio.gonzalez.monroy at intel.com>, Hemant
> > Agrawal <hemant.agrawal at nxp.com>, Ilya Maximets <i.maximets at samsung.com>,
> > dev at dpdk.org, Bruce Richardson <bruce.richardson at intel.com>, David
> > Marchand <david.marchand at 6wind.com>, Heetae Ahn
> > <heetae82.ahn at samsung.com>, Yuanhan Liu <yliu at fridaylinux.org>, Jianfeng
> > Tan <jianfeng.tan at intel.com>, Neil Horman <nhorman at tuxdriver.com>, Yulong
> > Pei <yulong.pei at intel.com>
> > Subject: Re: [PATCH v5 0/2] Balanced allocation of hugepages
> > 21/06/2017 10:41, Jerin Jacob:
> > > > > 1. There are many machines (arm/ppc), which do not support NUMA.
> > > > >
> > > > > https://wiki.linaro.org/LEG/Engineering/Kernel/NUMA
> > > > >
> > > >
> > > > I did find that link too, last modified 4 years ago.
> > > > Despite that, I could not find any ARM references in libnuma sources, but
> > > > Jerin proved that there is support for it.
> > > >
> > > > http://oss.sgi.com/projects/libnuma/
> > > > https://github.com/numactl/numactl
> > >
> > > Those Linaro links are very old. ARM64 NUMA supported has been added in 4.7 kernel.
> > > I guess we are talking about build time time dependency with libnuma here.
> > > Correct? I think, Even with old arm64 kernel(< 4.6), You can build against
> > > libnuma if it is present in rootfs. Just that at runtime, it will return
> > > NUMA support not available. Correct?
> > >
> > > How hard is detect the presence of "numaif.h" if existing build system does not
> > > support it? If it trivial, we can enable RTE_LIBRTE_EAL_NUMA_AWARE_HUGEPAGES
> > > if build environment has "numaif.h".
> > >
> > > Some example in linux kernel build system:
> > > http://lxr.linux.no/linux+v4.10.1/scripts/gcc-goto.sh
> > I think we should not try to detect numaif.h, because it should be
> > an error on platform supporting NUMA.
> I have installed libnuma on a NUMA and non NUMA machine.
> Compiled and ran following code on those machine and it could detect
> the numa availability. Could you add more details on the "error on
> platform supporting NUMA".
I was saying that we do not need to detect NUMA.
If we are building DPDK for a NUMA architecture and libnuma is not
available, then it will be a problem that the user must catch.
The easiest way to catch it, is to fail on the include of numaif.h.
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