selftests: net: tcp_mmap: Use huge pages in send path
There are significant gains using huge pages when
available, as shown in [1].
This patch adds mmap_large_buffer() and uses it
in client side (tx path of this reference tool)
Following patch will use the feature for server side.
[1] https://patchwork.ozlabs.org/project/netdev/patch/
20200820154359.
1806305-1-edumazet@google.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>