* [vm build] force Linux to drop cache before calling kvm
KVM need to allocate 2G memory for this build. The system memory might
be occupied by cache at the moment and doesn't have 2G chunk to give
out. Forcing Kernel to drop cache to boost the chance of getting 2G
memory.
Signed-off-by: Ying Xie <ying.xie@microsoft.com>
* [make] add option to enable/disable VS build memory preparation
Signed-off-by: Ying Xie <ying.xie@microsoft.com>
