On Mon, 2016-06-27 at 14:29 +0530, Arjun V wrote:
> On Monday, June 06/27/16, 2016 at 13:36:22 +0530, Eric Dumazet wrote:
> > On Mon, 2016-06-27 at 12:47 +0530, Arjun V wrote:
> >
> > > Eric,
> > >
> > > Thanks for the quick patch. It didn't help much. We still see packets
> > > larger than 65536 with the patch.
> > >
> > > Below is the dump_stack() trace I am seeing for packets larger than 65536
> > > in our xmit routine:
> >
> > What values do you get for skb->len ?
> >
> These are the skb->len values I am hitting in t4_eth_xmit() for around half
> hour run of netperf bidi(800 connections total)
> packet with skb->len 69570 detected
> packet with skb->len 66674 detected
Ok please add :
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index
5c7ed147449c1b7ba029b12e033ad779a631460a..39bd2a2b8f4d931c514fe62a00541efef29157ad
100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -845,6 +845,7 @@ static unsigned int tcp_xmit_size_goal(struct sock *sk, u32
mss_now,
{
struct tcp_sock *tp = tcp_sk(sk);
u32 new_size_goal, size_goal;
+ u32 res;
if (!large_allowed || !sk_can_gso(sk))
return mss_now;
@@ -862,7 +863,11 @@ static unsigned int tcp_xmit_size_goal(struct sock *sk,
u32 mss_now,
size_goal = tp->gso_segs * mss_now;
}
- return max(size_goal, mss_now);
+ res = max(size_goal, mss_now);
+ if (res >= 65536)
+ pr_err_once("tcp_xmit_size_goal() -> %u size_goal %u, mss_now
%u gso_max_size %u gso_segs %u\n",
+ res, size_goal, mss_now, sk->sk_gso_max_size,
tp->gso_segs);
+ return res;
}
static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
