android_kernel_motorola_sm6375/include
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Marcelo Ricardo Leitner 3822a5ff4b sctp: align MTU to a word
SCTP is a protocol that is aligned to a word (4 bytes). Thus using bare
MTU can sometimes return values that are not aligned, like for loopback,
which is 65536 but ipv4_mtu() limits that to 65535. This mis-alignment
will cause the last non-aligned bytes to never be used and can cause
issues with congestion control.

So it's better to just consider a lower MTU and keep congestion control
calcs saner as they are based on PMTU.

Same applies to icmp frag needed messages, which is also fixed by this
patch.

One other effect of this is the inability to send MTU-sized packet
without queueing or fragmentation and without hitting Nagle. As the
check performed at sctp_packet_can_append_data():

if (chunk->skb->len + q->out_qlen >= transport->pathmtu - packet->overhead)
	/* Enough data queued to fill a packet */
	return SCTP_XMIT_OK;

with the above example of MTU, if there are no other messages queued,
one cannot send a packet that just fits one packet (65532 bytes) and
without causing DATA chunk fragmentation or a delay.

v2:
 - Added WORD_TRUNC macro

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-20 16:31:12 -04:00
..
acpi Merge branches 'acpi-processor' and 'acpi-cppc' 2016-03-14 14:20:33 +01:00
asm-generic Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-03-17 11:33:45 -07:00
drm Merge remote-tracking branch 'asoc/topic/intel' into asoc-next 2016-03-13 15:16:26 +07:00
dt-bindings Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
keys
kvm
linux Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2016-03-19 16:31:54 -07:00
math-emu
media Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2016-03-19 16:31:54 -07:00
memory
misc
net sctp: align MTU to a word 2016-03-20 16:31:12 -04:00
pcmcia
ras
rdma Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
rxrpc
scsi Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-03-17 11:22:54 -07:00
soc
sound ASoC: Updates for v4.6 2016-03-14 14:03:29 +01:00
target Configfs changes for the 4.6 merge window: 2016-03-17 16:25:46 -07:00
trace ipv6, trace: fix tos reporting on fib6_table_lookup 2016-03-20 13:44:34 -04:00
uapi powerpc updates for 4.6 2016-03-19 15:38:41 -07:00
video
xen xen-netback: re-import canonical netif header 2016-03-13 22:08:01 -04:00
Kbuild