forked from Minki/linux
bbd8a0d3a3
dev_queue_xmit enqueue's a skb and calls qdisc_run which dequeue's the skb and xmits it. In most cases, the skb that is enqueue'd is the same one that is dequeue'd (unless the queue gets stopped or multiple cpu's write to the same queue and ends in a race with qdisc_run). For default qdiscs, we can remove the redundant enqueue/dequeue and simply xmit the skb since the default qdisc is work-conserving. The patch uses a new flag - TCQ_F_CAN_BYPASS to identify the default fast queue. The controversial part of the patch is incrementing qlen when a skb is requeued - this is to avoid checks like the second line below: + } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) && >> !q->gso_skb && + !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) { Results of a 2 hour testing for multiple netperf sessions (1, 2, 4, 8, 12 sessions on a 4 cpu system-X). The BW numbers are aggregate Mb/s across iterations tested with this version on System-X boxes with Chelsio 10gbps cards: ---------------------------------- Size | ORG BW NEW BW | ---------------------------------- 128K | 156964 159381 | 256K | 158650 162042 | ---------------------------------- Changes from ver1: 1. Move sch_direct_xmit declaration from sch_generic.h to pkt_sched.h 2. Update qdisc basic statistics for direct xmit path. 3. Set qlen to zero in qdisc_reset. 4. Changed some function names to more meaningful ones. Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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.. | ||
act_api.c | ||
act_gact.c | ||
act_ipt.c | ||
act_mirred.c | ||
act_nat.c | ||
act_pedit.c | ||
act_police.c | ||
act_simple.c | ||
act_skbedit.c | ||
cls_api.c | ||
cls_basic.c | ||
cls_cgroup.c | ||
cls_flow.c | ||
cls_fw.c | ||
cls_route.c | ||
cls_rsvp6.c | ||
cls_rsvp.c | ||
cls_rsvp.h | ||
cls_tcindex.c | ||
cls_u32.c | ||
em_cmp.c | ||
em_meta.c | ||
em_nbyte.c | ||
em_text.c | ||
em_u32.c | ||
ematch.c | ||
Kconfig | ||
Makefile | ||
sch_api.c | ||
sch_atm.c | ||
sch_blackhole.c | ||
sch_cbq.c | ||
sch_drr.c | ||
sch_dsmark.c | ||
sch_fifo.c | ||
sch_generic.c | ||
sch_gred.c | ||
sch_hfsc.c | ||
sch_htb.c | ||
sch_ingress.c | ||
sch_multiq.c | ||
sch_netem.c | ||
sch_prio.c | ||
sch_red.c | ||
sch_sfq.c | ||
sch_tbf.c | ||
sch_teql.c |