Re: [PATCH net-next v3 2/3] bonding: modify the old and add new xmit hash policies

[Eric Dumazet <eric.dumazet@gmail.com>]

On Thu, 2013-09-26 at 16:09 +0200, Nikolay Aleksandrov wrote:
> This patch adds two new hash policy modes which use skb_flow_dissect:
> 3 - Encapsulated layer 2+3
> 4 - Encapsulated layer 3+4
> There should be a good improvement for tunnel users in those modes.
> It also changes the old hash functions to:
> hash ^= (__force u32)flow.dst ^ (__force u32)flow.src;
> hash ^= (hash >> 16);
> hash ^= (hash >> 8);
> 
> Where hash will be initialized either to L2 hash, that is
> SRCMAC[5] XOR DSTMAC[5], or to flow->ports which should be extracted
> from the upper layer. Flow's dst and src are also extracted based on the
> xmit policy either directly from the buffer or by using skb_flow_dissect,
> but in both cases if the protocol is IPv6 then dst and src are obtained by
> ipv6_addr_hash() on the real addresses. In case of a non-dissectable
> packet, the algorithms fall back to L2 hashing.
> The bond_set_mode_ops() function is now obsolete and thus deleted
> because it was used only to set the proper hash policy. Also we trim a
> pointer from struct bonding because we no longer need to keep the hash
> function, now there's only a single hash function - bond_xmit_hash that
> works based on bond->params.xmit_policy.
> 
> The hash function and skb_flow_dissect were suggested by Eric Dumazet.
> The layer names were suggested by Andy Gospodarek, because I suck at
> semantics.
> 
> Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
> ---
> v2: fix a bug in bond_flow_dissect which might've caused the use of
>     uninitalized flow_keys and make use of skb_flow_get_ports
> v3: no change
> One line is intentionally left at 82 chars since it's the whole function
> and IMO looks better that way.
> 
>  drivers/net/bonding/bond_3ad.c   |   2 +-
>  drivers/net/bonding/bond_main.c  | 197 ++++++++++++++-------------------------
>  drivers/net/bonding/bond_sysfs.c |   2 -
>  drivers/net/bonding/bonding.h    |   3 +-
>  include/uapi/linux/if_bonding.h  |   2 +
>  5 files changed, 72 insertions(+), 134 deletions(-)


I love this patch, thanks for following up on this one.

Reviewed-by: Eric Dumazet <edumazet@google.com>