Match the config from ubuntu

As ubuntu 16.04 is using the same version kernel, we try to reuse the
config file from ubuntu server release.

Also added one rpm package required for building the new kernel config.

upstream-status: N/A

Change-Id: I471918eb1840bd36ba569abb63b2fa0b3d2fb4f3
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/kernel/arch/x86/configs/README.opnfv b/kernel/arch/x86/configs/README.opnfv
new file mode 100644
index 000000000..752ff7ba5
--- /dev/null
+++ b/kernel/arch/x86/configs/README.opnfv
@@ -0,0 +1,19 @@
+As the ubuntu 16.04 is based on 4.4 kernel, thus we can try to refer the config
+file for opnfv config file.
+
+The arch/x86/configs/config-4.4.0-62-generic is the config file used by ubuntu
+kernel. Comparing with the opnfv kernel, the key differences are:
+ a. Real time config support like NOHZ_FULL, PREMEPMT kernel, different RCU
+mechanism,
+ b.  Disabling some feature that may impact real time result, like power
+management functionality (C/P state). The hotplug support is disabled also
+temply now.
+ c.  Some ubuntu specific driver is not copied.
+ d. Some difference of build-in/module selection, because some config items
+are selected automatically and we don't figure out the default value difference
+yet. 
+ e. Some virtualization support like Xen/HyperV is not enabled yet, to avoid
+potential impact.
+
+In future, we should leave only item a/b and remove the differences caused by
+item c/d/e.