On Wed, Mar 30, 2016 at 6:37 PM, Soheil Hassas Yeganeh <soheil.k...@gmail.com> wrote: > From: Soheil Hassas Yeganeh <soh...@google.com> > > Currently, to avoid a cache line miss for accessing skb_shinfo, > tcp_ack_tstamp skips socket that do not have > SOF_TIMESTAMPING_TX_ACK bit set in sk_tsflags. This is > implemented based on an implicit assumption that the > SOF_TIMESTAMPING_TX_ACK is set via socket options for the > duration that ACK timestamps are needed. > > To implement per-write timestamps, this check should be > removed and replaced with a per-packet alternative that > quickly skips packets missing ACK timestamps marks without > a cache-line miss. > > To enable per-packet marking without a cache line miss, use > one bit in TCP_SKB_CB to mark a whether a SKB might need a > ack tx timestamp or not. Further checks in tcp_ack_tstamp are not > modified and work as before. > > Signed-off-by: Soheil Hassas Yeganeh <soh...@google.com>
Acked-by: Willem de Bruijn <will...@google.com>
