diff options
| -rw-r--r-- | include/net/pie.h | 31 | ||||
| -rw-r--r-- | net/sched/sch_fq_pie.c | 1 | ||||
| -rw-r--r-- | net/sched/sch_pie.c | 47 |
3 files changed, 33 insertions, 46 deletions
diff --git a/include/net/pie.h b/include/net/pie.h index fd5a37cb7993..3fe2361e03b4 100644 --- a/include/net/pie.h +++ b/include/net/pie.h @@ -8,7 +8,7 @@ #include <net/inet_ecn.h> #include <net/pkt_sched.h> -#define MAX_PROB U64_MAX +#define MAX_PROB (U64_MAX >> BITS_PER_BYTE) #define DTIME_INVALID U64_MAX #define QUEUE_THRESHOLD 16384 #define DQCOUNT_INVALID -1 @@ -38,16 +38,15 @@ struct pie_params { /** * struct pie_vars - contains pie variables - * @qdelay: current queue delay - * @qdelay_old: queue delay in previous qdelay calculation - * @burst_time: burst time allowance - * @dq_tstamp: timestamp at which dq rate was last calculated - * @prob: drop probability - * @accu_prob: accumulated drop probability - * @dq_count: number of bytes dequeued in a measurement cycle - * @avg_dq_rate: calculated average dq rate - * @qlen_old: queue length during previous qdelay calculation - * @accu_prob_overflows: number of times accu_prob overflows + * @qdelay: current queue delay + * @qdelay_old: queue delay in previous qdelay calculation + * @burst_time: burst time allowance + * @dq_tstamp: timestamp at which dq rate was last calculated + * @prob: drop probability + * @accu_prob: accumulated drop probability + * @dq_count: number of bytes dequeued in a measurement cycle + * @avg_dq_rate: calculated average dq rate + * @backlog_old: queue backlog during previous qdelay calculation */ struct pie_vars { psched_time_t qdelay; @@ -58,8 +57,7 @@ struct pie_vars { u64 accu_prob; u64 dq_count; u32 avg_dq_rate; - u32 qlen_old; - u8 accu_prob_overflows; + u32 backlog_old; }; /** @@ -107,7 +105,6 @@ static inline void pie_vars_init(struct pie_vars *vars) vars->accu_prob = 0; vars->dq_count = DQCOUNT_INVALID; vars->avg_dq_rate = 0; - vars->accu_prob_overflows = 0; } static inline struct pie_skb_cb *get_pie_cb(const struct sk_buff *skb) @@ -127,12 +124,12 @@ static inline void pie_set_enqueue_time(struct sk_buff *skb) } bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, - struct pie_vars *vars, u32 qlen, u32 packet_size); + struct pie_vars *vars, u32 backlog, u32 packet_size); void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, - struct pie_vars *vars, u32 qlen); + struct pie_vars *vars, u32 backlog); void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, - u32 qlen); + u32 backlog); #endif diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c index 214657eb3dfd..a9da8776bf5b 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -189,7 +189,6 @@ static int fq_pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, out: q->stats.dropped++; sel_flow->vars.accu_prob = 0; - sel_flow->vars.accu_prob_overflows = 0; __qdisc_drop(skb, to_free); qdisc_qstats_drop(sch); return NET_XMIT_CN; diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c index 915bcdb59a9f..f52442d39bf5 100644 --- a/net/sched/sch_pie.c +++ b/net/sched/sch_pie.c @@ -31,7 +31,7 @@ struct pie_sched_data { }; bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, - struct pie_vars *vars, u32 qlen, u32 packet_size) + struct pie_vars *vars, u32 backlog, u32 packet_size) { u64 rnd; u64 local_prob = vars->prob; @@ -51,7 +51,7 @@ bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, /* If we have fewer than 2 mtu-sized packets, disable pie_drop_early, * similar to min_th in RED */ - if (qlen < 2 * mtu) + if (backlog < 2 * mtu) return false; /* If bytemode is turned on, use packet size to compute new @@ -62,27 +62,19 @@ bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, else local_prob = vars->prob; - if (local_prob == 0) { + if (local_prob == 0) vars->accu_prob = 0; - vars->accu_prob_overflows = 0; - } - - if (local_prob > MAX_PROB - vars->accu_prob) - vars->accu_prob_overflows++; - - vars->accu_prob += local_prob; + else + vars->accu_prob += local_prob; - if (vars->accu_prob_overflows == 0 && - vars->accu_prob < (MAX_PROB / 100) * 85) + if (vars->accu_prob < (MAX_PROB / 100) * 85) return false; - if (vars->accu_prob_overflows == 8 && - vars->accu_prob >= MAX_PROB / 2) + if (vars->accu_prob >= (MAX_PROB / 2) * 17) return true; prandom_bytes(&rnd, 8); - if (rnd < local_prob) { + if ((rnd >> BITS_PER_BYTE) < local_prob) { vars->accu_prob = 0; - vars->accu_prob_overflows = 0; return true; } @@ -129,7 +121,6 @@ static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, out: q->stats.dropped++; q->vars.accu_prob = 0; - q->vars.accu_prob_overflows = 0; return qdisc_drop(skb, sch, to_free); } @@ -215,7 +206,7 @@ static int pie_change(struct Qdisc *sch, struct nlattr *opt, } void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, - struct pie_vars *vars, u32 qlen) + struct pie_vars *vars, u32 backlog) { psched_time_t now = psched_get_time(); u32 dtime = 0; @@ -231,7 +222,7 @@ void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, vars->dq_tstamp = now; - if (qlen == 0) + if (backlog == 0) vars->qdelay = 0; if (dtime == 0) @@ -244,7 +235,7 @@ void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, * we have enough packets to calculate the drain rate. Save * current time as dq_tstamp and start measurement cycle. */ - if (qlen >= QUEUE_THRESHOLD && vars->dq_count == DQCOUNT_INVALID) { + if (backlog >= QUEUE_THRESHOLD && vars->dq_count == DQCOUNT_INVALID) { vars->dq_tstamp = psched_get_time(); vars->dq_count = 0; } @@ -283,7 +274,7 @@ void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, * dq_count to 0 to re-enter the if block when the next * packet is dequeued */ - if (qlen < QUEUE_THRESHOLD) { + if (backlog < QUEUE_THRESHOLD) { vars->dq_count = DQCOUNT_INVALID; } else { vars->dq_count = 0; @@ -307,7 +298,7 @@ burst_allowance_reduction: EXPORT_SYMBOL_GPL(pie_process_dequeue); void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, - u32 qlen) + u32 backlog) { psched_time_t qdelay = 0; /* in pschedtime */ psched_time_t qdelay_old = 0; /* in pschedtime */ @@ -322,7 +313,7 @@ void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, vars->qdelay_old = vars->qdelay; if (vars->avg_dq_rate > 0) - qdelay = (qlen << PIE_SCALE) / vars->avg_dq_rate; + qdelay = (backlog << PIE_SCALE) / vars->avg_dq_rate; else qdelay = 0; } else { @@ -330,10 +321,10 @@ void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, qdelay_old = vars->qdelay_old; } - /* If qdelay is zero and qlen is not, it means qlen is very small, + /* If qdelay is zero and backlog is not, it means backlog is very small, * so we do not update probabilty in this round. */ - if (qdelay == 0 && qlen != 0) + if (qdelay == 0 && backlog != 0) update_prob = false; /* In the algorithm, alpha and beta are between 0 and 2 with typical @@ -363,8 +354,8 @@ void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, } /* alpha and beta should be between 0 and 32, in multiples of 1/16 */ - delta += alpha * (u64)(qdelay - params->target); - delta += beta * (u64)(qdelay - qdelay_old); + delta += alpha * (qdelay - params->target); + delta += beta * (qdelay - qdelay_old); oldprob = vars->prob; @@ -409,7 +400,7 @@ void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, vars->prob -= vars->prob / 64; vars->qdelay = qdelay; - vars->qlen_old = qlen; + vars->backlog_old = backlog; /* We restart the measurement cycle if the following conditions are met * 1. If the delay has been low for 2 consecutive Tupdate periods |