From: Subash Abhinov Kasiviswanathan <subas...@codeaurora.org>
Date: Thu, 23 Mar 2017 13:34:16 -0600
> Certain system process significant unconnected UDP workload.
> It would be preferrable to disable UDP early demux for those systems
> and enable it for TCP only.
>
> By disabling UDP demux, we see these slight gains on an ARM64 system-
> 782 -> 788Mbps unconnected single stream UDPv4
> 633 -> 654Mbps unconnected UDPv4 different sources
>
> The performance impact can change based on CPU architecure and cache
> sizes. There will not much difference seen if entire UDP hash table
> is in cache.
>
> Both sysctls are enabled by default to preserve existing behavior.
>
> v1->v2: Change function pointer instead of adding conditional as
> suggested by Stephen.
>
> v2->v3: Read once in callers to avoid issues due to compiler
> optimizations. Also update commit message with the tests.
>
> v3->v4: Store and use read once result instead of querying pointer
> again incorrectly.
>
> v4->v5: Refactor to avoid errors due to compilation with IPV6={m,n}
>
> Signed-off-by: Subash Abhinov Kasiviswanathan <subas...@codeaurora.org>
> Suggested-by: Eric Dumazet <eduma...@google.com>
Applied.
