aha/arch/powerpc
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next 2009-09-23 15:37:02 -07:00
configs Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2009-09-15 09:51:09 -07:00
include/asm net: Generalize socket rx gap / receive queue overflow cmsg 2009-10-12 13:26:31 -07:00
kernel powerpc: Cleanup linker script using new linker script macros. 2009-09-24 17:16:22 -07:00
kvm const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
lib powerpc: Add configurable -Werror for arch/powerpc 2009-06-16 14:15:45 +10:00
math-emu powerpc/math-emu: Fix efp dependence 2009-03-11 06:00:08 -05:00
mm powerpc/8xx: Fix regression introduced by cache coherency rewrite 2009-09-24 15:56:30 +10:00
oprofile powerpc: Remove unnecessary semicolons 2009-07-08 13:50:21 +10:00
platforms const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
sysdev powerpc: Change archdata dma_data to a union 2009-09-24 15:31:43 +10:00
xmon powerpc/4xx: Fix erroneous xmon warning on PowerPC 4xx 2009-09-24 15:31:49 +10:00
Kconfig powerpc: Increase NODES_SHIFT on 64bit from 4 to 8 2009-09-24 15:31:46 +10:00
Kconfig.debug powerpc: Add configurable -Werror for arch/powerpc 2009-06-16 14:15:45 +10:00
Makefile powerpc: Check for unsupported relocs when using CONFIG_RELOCATABLE 2009-09-24 15:31:40 +10:00
relocs_check.pl powerpc: Check for unsupported relocs when using CONFIG_RELOCATABLE 2009-09-24 15:31:40 +10:00