From: Jakub Kicinski Date: Mon, 15 Jan 2018 04:01:26 +0000 (-0800) Subject: net: sched: red: don't reset the backlog on every stat dump X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=416ef9b15c688b91edbf654ebe7bc349c9151147;p=openwrt%2Fstaging%2Fblogic.git net: sched: red: don't reset the backlog on every stat dump Commit 0dfb33a0d7e2 ("sch_red: report backlog information") copied child's backlog into RED's backlog. Back then RED did not maintain its own backlog counts. This has changed after commit 2ccccf5fb43f ("net_sched: update hierarchical backlog too") and commit d7f4f332f082 ("sch_red: update backlog as well"). Copying is no longer necessary. Tested: $ tc -s qdisc show dev veth0 qdisc red 1: root refcnt 2 limit 400000b min 30000b max 30000b ecn Sent 20942 bytes 221 pkt (dropped 0, overlimits 0 requeues 0) backlog 1260b 14p requeues 14 marked 0 early 0 pdrop 0 other 0 qdisc tbf 2: parent 1: rate 1Kbit burst 15000b lat 3585.0s Sent 20942 bytes 221 pkt (dropped 0, overlimits 138 requeues 0) backlog 1260b 14p requeues 14 Recently RED offload was added. We need to make sure drivers don't depend on resetting the stats. This means backlog should be treated like any other statistic: total_stat = new_hw_stat - prev_hw_stat; Adjust mlxsw. Signed-off-by: Jakub Kicinski Acked-by: Nogah Frankel Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c index fee9da81bce6..0b7670459051 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c @@ -247,6 +247,8 @@ mlxsw_sp_setup_tc_qdisc_red_clean_stats(struct mlxsw_sp_port *mlxsw_sp_port, stats_base->overlimits = red_base->prob_drop + red_base->prob_mark; stats_base->drops = red_base->prob_drop + red_base->pdrop; + + stats_base->backlog = 0; } static int @@ -306,6 +308,19 @@ mlxsw_sp_qdisc_red_replace(struct mlxsw_sp_port *mlxsw_sp_port, max, prob, p->is_ecn); } +static void +mlxsw_sp_qdisc_red_unoffload(struct mlxsw_sp_port *mlxsw_sp_port, + struct mlxsw_sp_qdisc *mlxsw_sp_qdisc, + void *params) +{ + struct tc_red_qopt_offload_params *p = params; + u64 backlog; + + backlog = mlxsw_sp_cells_bytes(mlxsw_sp_port->mlxsw_sp, + mlxsw_sp_qdisc->stats_base.backlog); + p->qstats->backlog -= backlog; +} + static int mlxsw_sp_qdisc_get_red_xstats(struct mlxsw_sp_port *mlxsw_sp_port, struct mlxsw_sp_qdisc *mlxsw_sp_qdisc, @@ -338,7 +353,7 @@ mlxsw_sp_qdisc_get_red_stats(struct mlxsw_sp_port *mlxsw_sp_port, struct mlxsw_sp_qdisc *mlxsw_sp_qdisc, struct tc_qopt_offload_stats *stats_ptr) { - u64 tx_bytes, tx_packets, overlimits, drops; + u64 tx_bytes, tx_packets, overlimits, drops, backlog; u8 tclass_num = mlxsw_sp_qdisc->tclass_num; struct mlxsw_sp_qdisc_stats *stats_base; struct mlxsw_sp_port_xstats *xstats; @@ -354,14 +369,18 @@ mlxsw_sp_qdisc_get_red_stats(struct mlxsw_sp_port *mlxsw_sp_port, stats_base->overlimits; drops = xstats->wred_drop[tclass_num] + xstats->tail_drop[tclass_num] - stats_base->drops; + backlog = xstats->backlog[tclass_num]; _bstats_update(stats_ptr->bstats, tx_bytes, tx_packets); stats_ptr->qstats->overlimits += overlimits; stats_ptr->qstats->drops += drops; stats_ptr->qstats->backlog += - mlxsw_sp_cells_bytes(mlxsw_sp_port->mlxsw_sp, - xstats->backlog[tclass_num]); + mlxsw_sp_cells_bytes(mlxsw_sp_port->mlxsw_sp, + backlog) - + mlxsw_sp_cells_bytes(mlxsw_sp_port->mlxsw_sp, + stats_base->backlog); + stats_base->backlog = backlog; stats_base->drops += drops; stats_base->overlimits += overlimits; stats_base->tx_bytes += tx_bytes; @@ -375,6 +394,7 @@ static struct mlxsw_sp_qdisc_ops mlxsw_sp_qdisc_ops_red = { .type = MLXSW_SP_QDISC_RED, .check_params = mlxsw_sp_qdisc_red_check_params, .replace = mlxsw_sp_qdisc_red_replace, + .unoffload = mlxsw_sp_qdisc_red_unoffload, .destroy = mlxsw_sp_qdisc_red_destroy, .get_stats = mlxsw_sp_qdisc_get_red_stats, .get_xstats = mlxsw_sp_qdisc_get_red_xstats, diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h index 9c341f003091..cc23c041a6d7 100644 --- a/include/net/pkt_cls.h +++ b/include/net/pkt_cls.h @@ -748,6 +748,7 @@ struct tc_red_qopt_offload_params { u32 max; u32 probability; bool is_ecn; + struct gnet_stats_queue *qstats; }; struct tc_red_qopt_offload { diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c index 0af1c1254e0b..16644b3d2362 100644 --- a/net/sched/sch_red.c +++ b/net/sched/sch_red.c @@ -167,6 +167,7 @@ static int red_offload(struct Qdisc *sch, bool enable) opt.set.max = q->parms.qth_max >> q->parms.Wlog; opt.set.probability = q->parms.max_P; opt.set.is_ecn = red_use_ecn(q); + opt.set.qstats = &sch->qstats; } else { opt.command = TC_RED_DESTROY; } @@ -322,7 +323,6 @@ static int red_dump(struct Qdisc *sch, struct sk_buff *skb) }; int err; - sch->qstats.backlog = q->qdisc->qstats.backlog; err = red_dump_offload_stats(sch, &opt); if (err) goto nla_put_failure;