From 789762ceec8f330b8a96e603812fa8dc543de4bf Mon Sep 17 00:00:00 2001 From: Soheil Hassas Yeganeh Date: Wed, 26 Sep 2018 16:57:04 -0400 Subject: [PATCH] tcp: adjust rcv zerocopy hints based on frag sizes When SKBs are coalesced, we can have SKBs with different frag sizes. Some with PAGE_SIZE and some not with PAGE_SIZE. Since recv_skip_hint is always set to the full SKB size, it can overestimate the amount that should be read using normal read for coalesced packets. Change the recv_skip_hint so that it only includes the first frags that are not of PAGE_SIZE. Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 78ac4d2e3827..2827fa5643bd 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1805,8 +1805,17 @@ static int tcp_zerocopy_receive(struct sock *sk, frags++; } } - if (frags->size != PAGE_SIZE || frags->page_offset) + if (frags->size != PAGE_SIZE || frags->page_offset) { + int remaining = zc->recv_skip_hint; + + while (remaining && (frags->size != PAGE_SIZE || + frags->page_offset)) { + remaining -= frags->size; + frags++; + } + zc->recv_skip_hint -= remaining; break; + } ret = vm_insert_page(vma, address + length, skb_frag_page(frags)); if (ret) -- 2.20.1