tree ee22c5074bfc6d19b54d7202ec336f8521e2d4bd
parent 29115cef85781057e78f0c967979edd40b16c209
author Arjun Roy <arjunroy@google.com> 1576439691 -0800
committer Jakub Kicinski <jakub.kicinski@netronome.com> 1576440821 -0800

tcp: Set rcv zerocopy hint correctly if skb last frag is < PAGE_SIZE

At present, if the last frag of paged data in a skb has < PAGE_SIZE
data, we compute the recv_skip_hint as being equal to the size of that
frag and the entire next skb.

Instead, just return the runt frag size as the hint.

recv_skip_hint is used by the application to skip over
bytes that can not be mmaped, so returning a too big
chunk is pessimistic and forces more bytes to be copied.

Signed-off-by: Arjun Roy <arjunroy@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>