linux/include
Eric Dumazet 563d34d057 tcp: dont drop MTU reduction indications
ICMP messages generated in output path if frame length is bigger than
mtu are actually lost because socket is owned by user (doing the xmit)

One example is the ipgre_tunnel_xmit() calling
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));

We had a similar case fixed in commit a34a101e1e (ipv6: disable GSO on
sockets hitting dst_allfrag).

Problem of such fix is that it relied on retransmit timers, so short tcp
sessions paid a too big latency increase price.

This patch uses the tcp_release_cb() infrastructure so that MTU
reduction messages (ICMP messages) are not lost, and no extra delay
is added in TCP transmits.

Reported-by: Maciej Żenczykowski <maze@google.com>
Diagnosed-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nandita Dukkipati <nanditad@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Tore Anderson <tore@fud.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-23 00:58:46 -07:00
..
acpi ACPI: fix acpi_bus.h build warnings when ACPI is not enabled 2012-06-04 00:29:11 -04:00
asm-generic mm: cma: fix condition check when setting global cma area 2012-07-06 12:02:04 +02:00
crypto
drm drm: drop comment about this header being autogenerated. 2012-06-22 11:04:55 +01:00
keys
linux tcp: dont drop MTU reduction indications 2012-07-23 00:58:46 -07:00
math-emu
media [media] patch for Asus My Cinema PS3-100 (1043:48cd) 2012-05-20 16:05:02 -03:00
memory
misc
mtd UBI: amend commentaries WRT dtype 2012-05-20 20:25:59 +03:00
net tcp: dont drop MTU reduction indications 2012-07-23 00:58:46 -07:00
pcmcia
rdma Merge branches 'core', 'cxgb4', 'ipath', 'iser', 'lockdep', 'mlx4', 'nes', 'ocrdma', 'qib' and 'raw-qp' into for-linus 2012-05-21 09:00:47 -07:00
rxrpc
scsi [SCSI] libsas: fix taskfile corruption in sas_ata_qc_fill_rtf 2012-07-08 09:49:14 +01:00
sound Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-06-25 14:53:09 -07:00
target target: Add TFO->put_session() caller for HW fabric session shutdown 2012-06-12 19:33:05 -07:00
trace rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacks 2012-06-06 20:43:27 -07:00
video fbdev updates for 3.5 2012-06-01 16:57:51 -07:00
xen xen: do not map the same GSI twice in PVHVM guests. 2012-05-21 14:11:36 -04:00
Kbuild