kernel_optimize_test/arch/xtensa
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 xtensa: move headers files to arch/xtensa/include 2008-11-06 10:25:09 -08:00
configs xtensa: enable m41t80 driver in s6105_defconfig 2009-06-22 02:38:11 -07:00
include/asm net: Generalize socket rx gap / receive queue overflow cmsg 2009-10-12 13:26:31 -07:00
kernel xtensa: Cleanup linker script using new linker script macros. 2009-09-24 17:16:21 -07:00
lib xtensa: move headers files to arch/xtensa/include 2008-11-06 10:25:09 -08:00
mm arches: drop superfluous casts in nr_free_pages() callers 2009-09-22 07:17:34 -07:00
platforms net: convert remaining non-symbolic return values in ndo_start_xmit() functions 2009-07-05 19:23:38 -07:00
variants xtensa: support s6000 gpio irqs and alternate function selection 2009-06-22 02:37:26 -07:00
Kconfig xtensa: implement ccount calibration for s6000 2009-05-11 22:00:17 -07:00
Kconfig.debug [PATCH] xtensa: Architecture support for Tensilica Xtensa Part 1 2005-06-24 00:05:21 -07:00
Makefile xtensa: only build platform or variant if they contain a Makefile 2009-04-03 00:06:45 -07:00