linux/arch/m32r
Neil Horman 3b885787ea net: Generalize socket rx gap / receive queue overflow cmsg
Create a new socket level option to report number of queue overflows

Recently I augmented the AF_PACKET protocol to report the number of frames lost
on the socket receive queue between any two enqueued frames.  This value was
exported via a SOL_PACKET level cmsg.  AFter I completed that work it was
requested that this feature be generalized so that any datagram oriented socket
could make use of this option.  As such I've created this patch, It creates a
new SOL_SOCKET level option called SO_RXQ_OVFL, which when enabled exports a
SOL_SOCKET level cmsg that reports the nubmer of times the sk_receive_queue
overflowed between any two given frames.  It also augments the AF_PACKET
protocol to take advantage of this new feature (as it previously did not touch
sk->sk_drops, which this patch uses to record the overflow count).  Tested
successfully by me.

Notes:

1) Unlike my previous patch, this patch simply records the sk_drops value, which
is not a number of drops between packets, but rather a total number of drops.
Deltas must be computed in user space.

2) While this patch currently works with datagram oriented protocols, it will
also be accepted by non-datagram oriented protocols. I'm not sure if thats
agreeable to everyone, but my argument in favor of doing so is that, for those
protocols which aren't applicable to this option, sk_drops will always be zero,
and reporting no drops on a receive queue that isn't used for those
non-participating protocols seems reasonable to me.  This also saves us having
to code in a per-protocol opt in mechanism.

3) This applies cleanly to net-next assuming that commit
977750076d (my af packet cmsg patch) is reverted

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-12 13:26:31 -07:00
..
boot kbuild: use INSTALLKERNEL to select customized installkernel script 2009-09-20 12:18:14 +02:00
configs eeprom: More consistent symbol names 2009-01-26 21:19:57 +01:00
include/asm net: Generalize socket rx gap / receive queue overflow cmsg 2009-10-12 13:26:31 -07:00
kernel m32r: Fix IPI function calls for SMP 2009-10-04 12:02:37 +09:00
lib m32r: export delay loop symbols 2009-10-04 12:02:36 +09:00
mm m32r: Fix set_memory() for DISCONTIGMEM 2009-10-04 12:02:36 +09:00
oprofile oprofile: more whitespace fixes 2008-10-15 20:55:51 +02:00
platforms m32r: remove obsolete hw_interrupt_type 2009-06-16 19:47:46 -07:00
Kconfig m32r: convert to use arch_gettimeoffset() 2009-09-22 07:17:43 -07:00
Kconfig.debug [PATCH] kconfig: clarify memory debug options 2006-03-25 08:22:54 -08:00
Makefile m32r: use KBUILD_DEFCONFIG 2008-04-29 14:46:00 +09:00