From: Paolo Abeni <pab...@redhat.com>
Date: Fri, 30 Sep 2016 16:56:45 +0200
> The commit 879c7220e828 ("net: pktgen: Observe needed_headroom
> of the device") increased the 'pkt_overhead' field value by
> LL_RESERVED_SPACE.
> As a side effect the generated packet size, computed as:
>
> /* Eth + IPh + UDPh + mpls */
> datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 -
> pkt_dev->pkt_overhead;
>
> is decreased by the same value.
> The above changed slightly the behavior of existing pktgen users,
> and made the procfs interface somewhat inconsistent.
> Fix it by restoring the previous pkt_overhead value and using
> LL_RESERVED_SPACE as extralen in skb allocation.
> Also, change pktgen_alloc_skb() to only partially reserve
> the headroom to allow the caller to prefetch from ll header
> start.
>
> v1 -> v2:
> - fixed some typos in the comments
>
> Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device")
> Suggested-by: Ben Greear <gree...@candelatech.com>
> Signed-off-by: Paolo Abeni <pab...@redhat.com>
Applied and queued up for -stable.
