On SMP, when ports are not allocated randomly, using the same starting
port on all processors will lead to bad performance as all processors
will try to get the same hashbucket spinlock: only one will succeed,
the rest will spin madly.

We solve this problem by making each processor start searching from a
different port. To not skip possibly valid port ranges we renormalize
the hint value too.

Signed-off-by: Lucian Adrian Grijincu <lgrijincu@ixiacom.com>
---
  net/ipv4/udp.c |   12 +++++++++---
  1 files changed, 9 insertions(+), 3 deletions(-)