From 79bdc4c862af7cf11a135a6fdf8093622043c862 Mon Sep 17 00:00:00 2001 From: Michal Kazior Date: Fri, 22 Apr 2016 14:15:58 +0200 Subject: codel: generalize the implementation This strips out qdisc specific bits from the code and makes it slightly more reusable. Codel will be used by wireless/mac80211 in the future. Signed-off-by: Michal Kazior Signed-off-by: David S. Miller --- include/net/codel.h | 64 +++++++++++++++++++++++++++++------------------- net/sched/sch_codel.c | 20 ++++++++++++--- net/sched/sch_fq_codel.c | 19 +++++++++++--- 3 files changed, 71 insertions(+), 32 deletions(-) diff --git a/include/net/codel.h b/include/net/codel.h index d168aca115cc..06ac687b4909 100644 --- a/include/net/codel.h +++ b/include/net/codel.h @@ -176,12 +176,10 @@ struct codel_stats { #define CODEL_DISABLED_THRESHOLD INT_MAX -static void codel_params_init(struct codel_params *params, - const struct Qdisc *sch) +static void codel_params_init(struct codel_params *params) { params->interval = MS2TIME(100); params->target = MS2TIME(5); - params->mtu = psched_mtu(qdisc_dev(sch)); params->ce_threshold = CODEL_DISABLED_THRESHOLD; params->ecn = false; } @@ -226,28 +224,38 @@ static codel_time_t codel_control_law(codel_time_t t, return t + reciprocal_scale(interval, rec_inv_sqrt << REC_INV_SQRT_SHIFT); } +typedef u32 (*codel_skb_len_t)(const struct sk_buff *skb); +typedef codel_time_t (*codel_skb_time_t)(const struct sk_buff *skb); +typedef void (*codel_skb_drop_t)(struct sk_buff *skb, void *ctx); +typedef struct sk_buff * (*codel_skb_dequeue_t)(struct codel_vars *vars, + void *ctx); + static bool codel_should_drop(const struct sk_buff *skb, - struct Qdisc *sch, + void *ctx, struct codel_vars *vars, struct codel_params *params, struct codel_stats *stats, + codel_skb_len_t skb_len_func, + codel_skb_time_t skb_time_func, + u32 *backlog, codel_time_t now) { bool ok_to_drop; + u32 skb_len; if (!skb) { vars->first_above_time = 0; return false; } - vars->ldelay = now - codel_get_enqueue_time(skb); - sch->qstats.backlog -= qdisc_pkt_len(skb); + skb_len = skb_len_func(skb); + vars->ldelay = now - skb_time_func(skb); - if (unlikely(qdisc_pkt_len(skb) > stats->maxpacket)) - stats->maxpacket = qdisc_pkt_len(skb); + if (unlikely(skb_len > stats->maxpacket)) + stats->maxpacket = skb_len; if (codel_time_before(vars->ldelay, params->target) || - sch->qstats.backlog <= params->mtu) { + *backlog <= params->mtu) { /* went below - stay below for at least interval */ vars->first_above_time = 0; return false; @@ -264,16 +272,17 @@ static bool codel_should_drop(const struct sk_buff *skb, return ok_to_drop; } -typedef struct sk_buff * (*codel_skb_dequeue_t)(struct codel_vars *vars, - struct Qdisc *sch); - -static struct sk_buff *codel_dequeue(struct Qdisc *sch, +static struct sk_buff *codel_dequeue(void *ctx, + u32 *backlog, struct codel_params *params, struct codel_vars *vars, struct codel_stats *stats, + codel_skb_len_t skb_len_func, + codel_skb_time_t skb_time_func, + codel_skb_drop_t drop_func, codel_skb_dequeue_t dequeue_func) { - struct sk_buff *skb = dequeue_func(vars, sch); + struct sk_buff *skb = dequeue_func(vars, ctx); codel_time_t now; bool drop; @@ -282,7 +291,8 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch, return skb; } now = codel_get_time(); - drop = codel_should_drop(skb, sch, vars, params, stats, now); + drop = codel_should_drop(skb, ctx, vars, params, stats, + skb_len_func, skb_time_func, backlog, now); if (vars->dropping) { if (!drop) { /* sojourn time below target - leave dropping state */ @@ -310,12 +320,15 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch, vars->rec_inv_sqrt); goto end; } - stats->drop_len += qdisc_pkt_len(skb); - qdisc_drop(skb, sch); + stats->drop_len += skb_len_func(skb); + drop_func(skb, ctx); stats->drop_count++; - skb = dequeue_func(vars, sch); - if (!codel_should_drop(skb, sch, - vars, params, stats, now)) { + skb = dequeue_func(vars, ctx); + if (!codel_should_drop(skb, ctx, + vars, params, stats, + skb_len_func, + skb_time_func, + backlog, now)) { /* leave dropping state */ vars->dropping = false; } else { @@ -333,13 +346,14 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch, if (params->ecn && INET_ECN_set_ce(skb)) { stats->ecn_mark++; } else { - stats->drop_len += qdisc_pkt_len(skb); - qdisc_drop(skb, sch); + stats->drop_len += skb_len_func(skb); + drop_func(skb, ctx); stats->drop_count++; - skb = dequeue_func(vars, sch); - drop = codel_should_drop(skb, sch, vars, params, - stats, now); + skb = dequeue_func(vars, ctx); + drop = codel_should_drop(skb, ctx, vars, params, + stats, skb_len_func, + skb_time_func, backlog, now); } vars->dropping = true; /* if min went above target close to when we last went below it diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c index 9b7e2980ee5c..512a94abe351 100644 --- a/net/sched/sch_codel.c +++ b/net/sched/sch_codel.c @@ -64,20 +64,33 @@ struct codel_sched_data { * to dequeue a packet from queue. Note: backlog is handled in * codel, we dont need to reduce it here. */ -static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch) +static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) { + struct Qdisc *sch = ctx; struct sk_buff *skb = __skb_dequeue(&sch->q); + if (skb) + sch->qstats.backlog -= qdisc_pkt_len(skb); + prefetch(&skb->end); /* we'll need skb_shinfo() */ return skb; } +static void drop_func(struct sk_buff *skb, void *ctx) +{ + struct Qdisc *sch = ctx; + + qdisc_drop(skb, sch); +} + static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch) { struct codel_sched_data *q = qdisc_priv(sch); struct sk_buff *skb; - skb = codel_dequeue(sch, &q->params, &q->vars, &q->stats, dequeue); + skb = codel_dequeue(sch, &sch->qstats.backlog, &q->params, &q->vars, + &q->stats, qdisc_pkt_len, codel_get_enqueue_time, + drop_func, dequeue_func); /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, * or HTB crashes. Defer it for next round. @@ -173,9 +186,10 @@ static int codel_init(struct Qdisc *sch, struct nlattr *opt) sch->limit = DEFAULT_CODEL_LIMIT; - codel_params_init(&q->params, sch); + codel_params_init(&q->params); codel_vars_init(&q->vars); codel_stats_init(&q->stats); + q->params.mtu = psched_mtu(qdisc_dev(sch)); if (opt) { int err = codel_change(sch, opt); diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c index d3fc8f9dd3d4..dcf7266e6901 100644 --- a/net/sched/sch_fq_codel.c +++ b/net/sched/sch_fq_codel.c @@ -220,8 +220,9 @@ static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch) * to dequeue a packet from queue. Note: backlog is handled in * codel, we dont need to reduce it here. */ -static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch) +static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) { + struct Qdisc *sch = ctx; struct fq_codel_sched_data *q = qdisc_priv(sch); struct fq_codel_flow *flow; struct sk_buff *skb = NULL; @@ -231,10 +232,18 @@ static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch) skb = dequeue_head(flow); q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); sch->q.qlen--; + sch->qstats.backlog -= qdisc_pkt_len(skb); } return skb; } +static void drop_func(struct sk_buff *skb, void *ctx) +{ + struct Qdisc *sch = ctx; + + qdisc_drop(skb, sch); +} + static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch) { struct fq_codel_sched_data *q = qdisc_priv(sch); @@ -263,8 +272,9 @@ begin: prev_ecn_mark = q->cstats.ecn_mark; prev_backlog = sch->qstats.backlog; - skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats, - dequeue); + skb = codel_dequeue(sch, &sch->qstats.backlog, &q->cparams, + &flow->cvars, &q->cstats, qdisc_pkt_len, + codel_get_enqueue_time, drop_func, dequeue_func); flow->dropped += q->cstats.drop_count - prev_drop_count; flow->dropped += q->cstats.ecn_mark - prev_ecn_mark; @@ -423,9 +433,10 @@ static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt) q->perturbation = prandom_u32(); INIT_LIST_HEAD(&q->new_flows); INIT_LIST_HEAD(&q->old_flows); - codel_params_init(&q->cparams, sch); + codel_params_init(&q->cparams); codel_stats_init(&q->cstats); q->cparams.ecn = true; + q->cparams.mtu = psched_mtu(qdisc_dev(sch)); if (opt) { int err = fq_codel_change(sch, opt); -- cgit v1.2.3-59-g8ed1b