linux/net/sched
Jarek Poplawski 8caf153974 net: sch_netem: Fix an inconsistency in ingress netem timestamps.
Alex Sidorenko reported:

"while experimenting with 'netem' we have found some strange behaviour. It
seemed that ingress delay as measured by 'ping' command shows up on some
hosts but not on others.

After some investigation I have found that the problem is that skbuff->tstamp
field value depends on whether there are any packet sniffers enabled. That
is:

- if any ptype_all handler is registered, the tstamp field is as expected
- if there are no ptype_all handlers, the tstamp field does not show the delay"

This patch prevents unnecessary update of tstamp in dev_queue_xmit_nit()
on ingress path (with act_mirred) adding a check, so minimal overhead on
the fast path, but only when sniffers etc. are active.

Since netem at ingress seems to logically emulate a network before a host,
tstamp is zeroed to trigger the update and pretend delays are from the
outside.

Reported-by: Alex Sidorenko <alexandre.sidorenko@hp.com>
Tested-by: Alex Sidorenko <alexandre.sidorenko@hp.com>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-20 02:14:59 -07:00
..
Kconfig cls_cgroup: clean up Kconfig 2008-12-29 19:40:46 -08:00
Makefile pkt_sched: add DRR scheduler 2008-11-20 04:10:00 -08:00
act_api.c tc: propogate errors from tcf_hash_create 2008-11-25 21:13:25 -08:00
act_gact.c tc: propogate errors from tcf_hash_create 2008-11-25 21:13:25 -08:00
act_ipt.c tc: propogate errors from tcf_hash_create 2008-11-25 21:13:25 -08:00
act_mirred.c tc: propogate errors from tcf_hash_create 2008-11-25 21:13:25 -08:00
act_nat.c tc: propogate errors from tcf_hash_create 2008-11-25 21:13:25 -08:00
act_pedit.c tc: propogate errors from tcf_hash_create 2008-11-25 21:13:25 -08:00
act_police.c pkt_sched: act_police: Fix a rate estimator test. 2009-03-04 17:38:10 -08:00
act_simple.c tc: propogate errors from tcf_hash_create 2008-11-25 21:13:25 -08:00
act_skbedit.c tc: propogate errors from tcf_hash_create 2008-11-25 21:13:25 -08:00
cls_api.c pkt_sched: remove unnecessary xchg() in packet classifiers 2008-11-20 04:14:28 -08:00
cls_basic.c pkt_sched: remove unnecessary xchg() in packet classifiers 2008-11-20 04:14:28 -08:00
cls_cgroup.c cls_cgroup: clean up for cgroup part 2008-12-29 19:40:45 -08:00
cls_flow.c CRED: Use creds in file structs 2008-11-14 10:39:25 +11:00
cls_fw.c pkt_sched: remove unnecessary xchg() in packet classifiers 2008-11-20 04:14:28 -08:00
cls_route.c pkt_sched: remove unnecessary xchg() in packet classifiers 2008-11-20 04:14:28 -08:00
cls_rsvp.c [NET_SCHED]: Remove unnecessary includes 2007-07-10 22:16:41 -07:00
cls_rsvp.h [NET_SCHED]: Use nla_policy for attribute validation in classifiers 2008-01-28 15:11:23 -08:00
cls_rsvp6.c [NET_SCHED]: Remove unnecessary includes 2007-07-10 22:16:41 -07:00
cls_tcindex.c pkt_sched: remove unnecessary xchg() in packet classifiers 2008-11-20 04:14:28 -08:00
cls_u32.c pkt_sched: cls_u32: Fix locking in u32_change() 2009-01-05 18:14:19 -08:00
em_cmp.c net: em_cmp.c use unaligned access helpers 2008-09-22 19:20:51 -07:00
em_meta.c netsched: Allow meta match on vlan tag on receive 2009-04-13 18:12:57 -07:00
em_nbyte.c [NET_SCHED]: ematch: module autoloading 2007-07-11 19:46:26 -07:00
em_text.c [NET_SCHED]: Convert classifiers from rtnetlink to new netlink API 2008-01-28 15:11:11 -08:00
em_u32.c [PKT_SCHED]: annotate cls_u32 2008-03-17 22:46:46 -07:00
ematch.c ematch: simpler tcf_em_unregister() 2008-11-16 23:01:49 -08:00
sch_api.c pkt_sched: sch_hfsc: sch_htb: Add non-work-conserving warning handler. 2009-02-01 01:12:42 -08:00
sch_atm.c pkt_sched: remove unnecessary xchg() in packet schedulers 2008-11-20 04:11:36 -08:00
sch_blackhole.c pkt_sched: Add qdisc->ops->peek() implementation. 2008-10-31 00:45:55 -07:00
sch_cbq.c pkt_sched: Change misleading code in class delete. 2009-03-15 20:00:19 -07:00
sch_drr.c pkt_sched: Change misleading code in class delete. 2009-03-15 20:00:19 -07:00
sch_dsmark.c pkt_sched: remove unnecessary xchg() in packet schedulers 2008-11-20 04:11:36 -08:00
sch_fifo.c pkt_sched: Remove qdisc->ops->requeue() etc. 2008-11-13 22:56:30 -08:00
sch_generic.c Revert "net: Fix for initial link state in 2.6.28" 2009-01-05 16:01:51 -08:00
sch_gred.c pkt_sched: Remove qdisc->ops->requeue() etc. 2008-11-13 22:56:30 -08:00
sch_hfsc.c pkt_sched: Change misleading code in class delete. 2009-03-15 20:00:19 -07:00
sch_htb.c pkt_sched: Change misleading code in class delete. 2009-03-15 20:00:19 -07:00
sch_ingress.c net_sched: Add accessor function for packet length for qdiscs 2008-07-20 00:08:27 -07:00
sch_multiq.c pkt_sched: sch_multiq: Change errno on non-multiqueue devices use. 2009-02-10 00:11:21 -08:00
sch_netem.c net: sch_netem: Fix an inconsistency in ingress netem timestamps. 2009-04-20 02:14:59 -07:00
sch_prio.c pkt_sched: remove unnecessary xchg() in packet schedulers 2008-11-20 04:11:36 -08:00
sch_red.c pkt_sched: remove unnecessary xchg() in packet schedulers 2008-11-20 04:11:36 -08:00
sch_sfq.c remove lots of double-semicolons 2009-01-08 08:31:14 -08:00
sch_tbf.c net/*: use linux/kernel.h swap() 2009-03-21 13:36:17 -07:00
sch_teql.c sch_teql: convert to net_device_ops 2009-01-06 10:45:57 -08:00