On 6/27/2017 2:56 PM, Thomas Monjalon wrote:
27/06/2017 11:13, Hemant Agrawal:
On 6/21/2017 4:52 PM, Jerin Jacob wrote:
From: Ilya Maximets <i.maxim...@samsung.com>
From: Thomas Monjalon <tho...@monjalon.net>
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.
libnuma is not really _architecture_ depended.
Ilya Maximets patch disables NUMA support in common arm64 config.I
think, It is not correct, We should not disable on any archs generic config.
IMO, It should be enabled by default in common config and then we can
detect the presence of numaif.h, if not available OR a target does not need it
explicitly, proceed with disabling
RTE_LIBRTE_EAL_NUMA_AWARE_HUGEPAGES. I think, That is more portable.
Detecting of headers is impossible until dpdk doesn't have dynamic build
configuration system like autotools, CMake or meson.
Right now we just can't do that.
I agree. Unless if we do something like linux kernel does it below
http://elixir.free-electrons.com/linux/latest/source/scripts/kconfig/lxdialog/check-lxdialog.sh
Either way, I think, you can enable RTE_LIBRTE_EAL_NUMA_AWARE_HUGEPAGES in
generic arm64 config and disable on defconfig_arm64-dpaa2-linuxapp-gcc(as
Hemant requested) or
any sub arch target that does not need in RTE_LIBRTE_EAL_NUMA_AWARE_HUGEPAGES.
No, this is not acceptable. it should not be enabled in generic arm64.
It can be enabled in specific ARM platforms, which support NUMA
architecture.
We also use generic ARM code on various of our platform when running
with non-dpaa and/or virtio-net. So enabling it will break all those
platforms.
Which platforms?
It is your non-upstreamed code. You have to deal with it.
You should disable NUMA in the config of these platforms.
See my reply in other thread. This is nothing to do with up-streaming.
All NXP - low end non-dpaa platforms, which don't have any platform
specific code, we use "arm64-armv8a-linuxapp-gcc" as the build config.
There is no need to create special configs for these platforms.
Creating a "non-NUMA" generic config will be an over-kill.
