mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 23:56:39 +07:00
63862b5bef
This patch removes the net_random and net_srandom macros and replaces them with direct calls to the prandom ones. As new commits only seem to use prandom_u32 there is no use to keep them around. This change makes it easier to grep for users of prandom_u32. Signed-off-by: Aruna-Hewapathirane <aruna.hewapathirane@gmail.com> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
556 lines
15 KiB
C
556 lines
15 KiB
C
/* Copyright (C) 2013 Cisco Systems, Inc, 2013.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* Author: Vijay Subramanian <vijaynsu@cisco.com>
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* Author: Mythili Prabhu <mysuryan@cisco.com>
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*
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* ECN support is added by Naeem Khademi <naeemk@ifi.uio.no>
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* University of Oslo, Norway.
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/skbuff.h>
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#include <net/pkt_sched.h>
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#include <net/inet_ecn.h>
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#define QUEUE_THRESHOLD 10000
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#define DQCOUNT_INVALID -1
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#define MAX_PROB 0xffffffff
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#define PIE_SCALE 8
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/* parameters used */
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struct pie_params {
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psched_time_t target; /* user specified target delay in pschedtime */
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u32 tupdate; /* timer frequency (in jiffies) */
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u32 limit; /* number of packets that can be enqueued */
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u32 alpha; /* alpha and beta are between -4 and 4 */
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u32 beta; /* and are used for shift relative to 1 */
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bool ecn; /* true if ecn is enabled */
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bool bytemode; /* to scale drop early prob based on pkt size */
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};
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/* variables used */
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struct pie_vars {
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u32 prob; /* probability but scaled by u32 limit. */
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psched_time_t burst_time;
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psched_time_t qdelay;
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psched_time_t qdelay_old;
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u64 dq_count; /* measured in bytes */
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psched_time_t dq_tstamp; /* drain rate */
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u32 avg_dq_rate; /* bytes per pschedtime tick,scaled */
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u32 qlen_old; /* in bytes */
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};
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/* statistics gathering */
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struct pie_stats {
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u32 packets_in; /* total number of packets enqueued */
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u32 dropped; /* packets dropped due to pie_action */
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u32 overlimit; /* dropped due to lack of space in queue */
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u32 maxq; /* maximum queue size */
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u32 ecn_mark; /* packets marked with ECN */
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};
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/* private data for the Qdisc */
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struct pie_sched_data {
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struct pie_params params;
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struct pie_vars vars;
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struct pie_stats stats;
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struct timer_list adapt_timer;
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};
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static void pie_params_init(struct pie_params *params)
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{
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params->alpha = 2;
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params->beta = 20;
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params->tupdate = usecs_to_jiffies(30 * USEC_PER_MSEC); /* 30 ms */
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params->limit = 1000; /* default of 1000 packets */
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params->target = PSCHED_NS2TICKS(20 * NSEC_PER_MSEC); /* 20 ms */
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params->ecn = false;
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params->bytemode = false;
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}
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static void pie_vars_init(struct pie_vars *vars)
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{
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vars->dq_count = DQCOUNT_INVALID;
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vars->avg_dq_rate = 0;
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/* default of 100 ms in pschedtime */
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vars->burst_time = PSCHED_NS2TICKS(100 * NSEC_PER_MSEC);
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}
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static bool drop_early(struct Qdisc *sch, u32 packet_size)
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{
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struct pie_sched_data *q = qdisc_priv(sch);
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u32 rnd;
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u32 local_prob = q->vars.prob;
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u32 mtu = psched_mtu(qdisc_dev(sch));
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/* If there is still burst allowance left skip random early drop */
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if (q->vars.burst_time > 0)
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return false;
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/* If current delay is less than half of target, and
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* if drop prob is low already, disable early_drop
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*/
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if ((q->vars.qdelay < q->params.target / 2)
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&& (q->vars.prob < MAX_PROB / 5))
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return false;
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/* If we have fewer than 2 mtu-sized packets, disable drop_early,
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* similar to min_th in RED
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*/
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if (sch->qstats.backlog < 2 * mtu)
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return false;
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/* If bytemode is turned on, use packet size to compute new
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* probablity. Smaller packets will have lower drop prob in this case
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*/
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if (q->params.bytemode && packet_size <= mtu)
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local_prob = (local_prob / mtu) * packet_size;
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else
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local_prob = q->vars.prob;
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rnd = prandom_u32();
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if (rnd < local_prob)
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return true;
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return false;
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}
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static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
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{
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struct pie_sched_data *q = qdisc_priv(sch);
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bool enqueue = false;
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if (unlikely(qdisc_qlen(sch) >= sch->limit)) {
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q->stats.overlimit++;
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goto out;
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}
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if (!drop_early(sch, skb->len)) {
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enqueue = true;
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} else if (q->params.ecn && (q->vars.prob <= MAX_PROB / 10) &&
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INET_ECN_set_ce(skb)) {
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/* If packet is ecn capable, mark it if drop probability
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* is lower than 10%, else drop it.
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*/
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q->stats.ecn_mark++;
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enqueue = true;
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}
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/* we can enqueue the packet */
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if (enqueue) {
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q->stats.packets_in++;
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if (qdisc_qlen(sch) > q->stats.maxq)
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q->stats.maxq = qdisc_qlen(sch);
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return qdisc_enqueue_tail(skb, sch);
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}
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out:
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q->stats.dropped++;
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return qdisc_drop(skb, sch);
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}
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static const struct nla_policy pie_policy[TCA_PIE_MAX + 1] = {
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[TCA_PIE_TARGET] = {.type = NLA_U32},
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[TCA_PIE_LIMIT] = {.type = NLA_U32},
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[TCA_PIE_TUPDATE] = {.type = NLA_U32},
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[TCA_PIE_ALPHA] = {.type = NLA_U32},
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[TCA_PIE_BETA] = {.type = NLA_U32},
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[TCA_PIE_ECN] = {.type = NLA_U32},
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[TCA_PIE_BYTEMODE] = {.type = NLA_U32},
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};
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static int pie_change(struct Qdisc *sch, struct nlattr *opt)
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{
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struct pie_sched_data *q = qdisc_priv(sch);
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struct nlattr *tb[TCA_PIE_MAX + 1];
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unsigned int qlen;
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int err;
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if (!opt)
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return -EINVAL;
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err = nla_parse_nested(tb, TCA_PIE_MAX, opt, pie_policy);
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if (err < 0)
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return err;
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sch_tree_lock(sch);
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/* convert from microseconds to pschedtime */
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if (tb[TCA_PIE_TARGET]) {
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/* target is in us */
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u32 target = nla_get_u32(tb[TCA_PIE_TARGET]);
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/* convert to pschedtime */
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q->params.target = PSCHED_NS2TICKS((u64)target * NSEC_PER_USEC);
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}
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/* tupdate is in jiffies */
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if (tb[TCA_PIE_TUPDATE])
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q->params.tupdate = usecs_to_jiffies(nla_get_u32(tb[TCA_PIE_TUPDATE]));
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if (tb[TCA_PIE_LIMIT]) {
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u32 limit = nla_get_u32(tb[TCA_PIE_LIMIT]);
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q->params.limit = limit;
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sch->limit = limit;
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}
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if (tb[TCA_PIE_ALPHA])
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q->params.alpha = nla_get_u32(tb[TCA_PIE_ALPHA]);
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if (tb[TCA_PIE_BETA])
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q->params.beta = nla_get_u32(tb[TCA_PIE_BETA]);
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if (tb[TCA_PIE_ECN])
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q->params.ecn = nla_get_u32(tb[TCA_PIE_ECN]);
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if (tb[TCA_PIE_BYTEMODE])
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q->params.bytemode = nla_get_u32(tb[TCA_PIE_BYTEMODE]);
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/* Drop excess packets if new limit is lower */
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qlen = sch->q.qlen;
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while (sch->q.qlen > sch->limit) {
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struct sk_buff *skb = __skb_dequeue(&sch->q);
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sch->qstats.backlog -= qdisc_pkt_len(skb);
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qdisc_drop(skb, sch);
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}
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qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen);
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sch_tree_unlock(sch);
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return 0;
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}
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static void pie_process_dequeue(struct Qdisc *sch, struct sk_buff *skb)
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{
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struct pie_sched_data *q = qdisc_priv(sch);
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int qlen = sch->qstats.backlog; /* current queue size in bytes */
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/* If current queue is about 10 packets or more and dq_count is unset
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* we have enough packets to calculate the drain rate. Save
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* current time as dq_tstamp and start measurement cycle.
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*/
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if (qlen >= QUEUE_THRESHOLD && q->vars.dq_count == DQCOUNT_INVALID) {
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q->vars.dq_tstamp = psched_get_time();
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q->vars.dq_count = 0;
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}
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/* Calculate the average drain rate from this value. If queue length
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* has receded to a small value viz., <= QUEUE_THRESHOLD bytes,reset
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* the dq_count to -1 as we don't have enough packets to calculate the
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* drain rate anymore The following if block is entered only when we
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* have a substantial queue built up (QUEUE_THRESHOLD bytes or more)
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* and we calculate the drain rate for the threshold here. dq_count is
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* in bytes, time difference in psched_time, hence rate is in
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* bytes/psched_time.
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*/
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if (q->vars.dq_count != DQCOUNT_INVALID) {
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q->vars.dq_count += skb->len;
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if (q->vars.dq_count >= QUEUE_THRESHOLD) {
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psched_time_t now = psched_get_time();
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u32 dtime = now - q->vars.dq_tstamp;
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u32 count = q->vars.dq_count << PIE_SCALE;
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if (dtime == 0)
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return;
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count = count / dtime;
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if (q->vars.avg_dq_rate == 0)
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q->vars.avg_dq_rate = count;
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else
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q->vars.avg_dq_rate =
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(q->vars.avg_dq_rate -
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(q->vars.avg_dq_rate >> 3)) + (count >> 3);
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/* If the queue has receded below the threshold, we hold
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* on to the last drain rate calculated, else we reset
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* dq_count to 0 to re-enter the if block when the next
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* packet is dequeued
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*/
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if (qlen < QUEUE_THRESHOLD)
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q->vars.dq_count = DQCOUNT_INVALID;
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else {
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q->vars.dq_count = 0;
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q->vars.dq_tstamp = psched_get_time();
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}
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if (q->vars.burst_time > 0) {
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if (q->vars.burst_time > dtime)
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q->vars.burst_time -= dtime;
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else
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q->vars.burst_time = 0;
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}
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}
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}
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}
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static void calculate_probability(struct Qdisc *sch)
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{
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struct pie_sched_data *q = qdisc_priv(sch);
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u32 qlen = sch->qstats.backlog; /* queue size in bytes */
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psched_time_t qdelay = 0; /* in pschedtime */
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psched_time_t qdelay_old = q->vars.qdelay; /* in pschedtime */
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s32 delta = 0; /* determines the change in probability */
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u32 oldprob;
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u32 alpha, beta;
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bool update_prob = true;
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q->vars.qdelay_old = q->vars.qdelay;
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if (q->vars.avg_dq_rate > 0)
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qdelay = (qlen << PIE_SCALE) / q->vars.avg_dq_rate;
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else
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qdelay = 0;
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/* If qdelay is zero and qlen is not, it means qlen is very small, less
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* than dequeue_rate, so we do not update probabilty in this round
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*/
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if (qdelay == 0 && qlen != 0)
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update_prob = false;
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/* Add ranges for alpha and beta, more aggressive for high dropping
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* mode and gentle steps for light dropping mode
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* In light dropping mode, take gentle steps; in medium dropping mode,
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* take medium steps; in high dropping mode, take big steps.
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*/
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if (q->vars.prob < MAX_PROB / 100) {
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alpha =
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(q->params.alpha * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 7;
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beta =
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(q->params.beta * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 7;
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} else if (q->vars.prob < MAX_PROB / 10) {
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alpha =
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(q->params.alpha * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 5;
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beta =
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(q->params.beta * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 5;
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} else {
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alpha =
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(q->params.alpha * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4;
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beta =
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(q->params.beta * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4;
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}
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/* alpha and beta should be between 0 and 32, in multiples of 1/16 */
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delta += alpha * ((qdelay - q->params.target));
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delta += beta * ((qdelay - qdelay_old));
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oldprob = q->vars.prob;
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/* to ensure we increase probability in steps of no more than 2% */
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if (delta > (s32) (MAX_PROB / (100 / 2)) &&
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q->vars.prob >= MAX_PROB / 10)
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delta = (MAX_PROB / 100) * 2;
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/* Non-linear drop:
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* Tune drop probability to increase quickly for high delays(>= 250ms)
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* 250ms is derived through experiments and provides error protection
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*/
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if (qdelay > (PSCHED_NS2TICKS(250 * NSEC_PER_MSEC)))
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delta += MAX_PROB / (100 / 2);
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q->vars.prob += delta;
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if (delta > 0) {
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/* prevent overflow */
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if (q->vars.prob < oldprob) {
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q->vars.prob = MAX_PROB;
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/* Prevent normalization error. If probability is at
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* maximum value already, we normalize it here, and
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* skip the check to do a non-linear drop in the next
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* section.
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*/
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update_prob = false;
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}
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} else {
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/* prevent underflow */
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if (q->vars.prob > oldprob)
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q->vars.prob = 0;
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}
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/* Non-linear drop in probability: Reduce drop probability quickly if
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* delay is 0 for 2 consecutive Tupdate periods.
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*/
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if ((qdelay == 0) && (qdelay_old == 0) && update_prob)
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q->vars.prob = (q->vars.prob * 98) / 100;
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q->vars.qdelay = qdelay;
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q->vars.qlen_old = qlen;
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/* We restart the measurement cycle if the following conditions are met
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* 1. If the delay has been low for 2 consecutive Tupdate periods
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* 2. Calculated drop probability is zero
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* 3. We have atleast one estimate for the avg_dq_rate ie.,
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* is a non-zero value
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*/
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if ((q->vars.qdelay < q->params.target / 2) &&
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(q->vars.qdelay_old < q->params.target / 2) &&
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(q->vars.prob == 0) &&
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(q->vars.avg_dq_rate > 0))
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pie_vars_init(&q->vars);
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}
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static void pie_timer(unsigned long arg)
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{
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struct Qdisc *sch = (struct Qdisc *)arg;
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struct pie_sched_data *q = qdisc_priv(sch);
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spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
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spin_lock(root_lock);
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calculate_probability(sch);
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/* reset the timer to fire after 'tupdate'. tupdate is in jiffies. */
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if (q->params.tupdate)
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mod_timer(&q->adapt_timer, jiffies + q->params.tupdate);
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spin_unlock(root_lock);
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}
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static int pie_init(struct Qdisc *sch, struct nlattr *opt)
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{
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struct pie_sched_data *q = qdisc_priv(sch);
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pie_params_init(&q->params);
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pie_vars_init(&q->vars);
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sch->limit = q->params.limit;
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setup_timer(&q->adapt_timer, pie_timer, (unsigned long)sch);
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mod_timer(&q->adapt_timer, jiffies + HZ / 2);
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if (opt) {
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int err = pie_change(sch, opt);
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if (err)
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return err;
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}
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return 0;
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}
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static int pie_dump(struct Qdisc *sch, struct sk_buff *skb)
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{
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struct pie_sched_data *q = qdisc_priv(sch);
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struct nlattr *opts;
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opts = nla_nest_start(skb, TCA_OPTIONS);
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if (opts == NULL)
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goto nla_put_failure;
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/* convert target from pschedtime to us */
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if (nla_put_u32(skb, TCA_PIE_TARGET,
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((u32) PSCHED_TICKS2NS(q->params.target)) /
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NSEC_PER_USEC) ||
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nla_put_u32(skb, TCA_PIE_LIMIT, sch->limit) ||
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nla_put_u32(skb, TCA_PIE_TUPDATE, jiffies_to_usecs(q->params.tupdate)) ||
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nla_put_u32(skb, TCA_PIE_ALPHA, q->params.alpha) ||
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nla_put_u32(skb, TCA_PIE_BETA, q->params.beta) ||
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nla_put_u32(skb, TCA_PIE_ECN, q->params.ecn) ||
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nla_put_u32(skb, TCA_PIE_BYTEMODE, q->params.bytemode))
|
|
goto nla_put_failure;
|
|
|
|
return nla_nest_end(skb, opts);
|
|
|
|
nla_put_failure:
|
|
nla_nest_cancel(skb, opts);
|
|
return -1;
|
|
|
|
}
|
|
|
|
static int pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
struct tc_pie_xstats st = {
|
|
.prob = q->vars.prob,
|
|
.delay = ((u32) PSCHED_TICKS2NS(q->vars.qdelay)) /
|
|
NSEC_PER_USEC,
|
|
/* unscale and return dq_rate in bytes per sec */
|
|
.avg_dq_rate = q->vars.avg_dq_rate *
|
|
(PSCHED_TICKS_PER_SEC) >> PIE_SCALE,
|
|
.packets_in = q->stats.packets_in,
|
|
.overlimit = q->stats.overlimit,
|
|
.maxq = q->stats.maxq,
|
|
.dropped = q->stats.dropped,
|
|
.ecn_mark = q->stats.ecn_mark,
|
|
};
|
|
|
|
return gnet_stats_copy_app(d, &st, sizeof(st));
|
|
}
|
|
|
|
static struct sk_buff *pie_qdisc_dequeue(struct Qdisc *sch)
|
|
{
|
|
struct sk_buff *skb;
|
|
skb = __qdisc_dequeue_head(sch, &sch->q);
|
|
|
|
if (!skb)
|
|
return NULL;
|
|
|
|
pie_process_dequeue(sch, skb);
|
|
return skb;
|
|
}
|
|
|
|
static void pie_reset(struct Qdisc *sch)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
qdisc_reset_queue(sch);
|
|
pie_vars_init(&q->vars);
|
|
}
|
|
|
|
static void pie_destroy(struct Qdisc *sch)
|
|
{
|
|
struct pie_sched_data *q = qdisc_priv(sch);
|
|
q->params.tupdate = 0;
|
|
del_timer_sync(&q->adapt_timer);
|
|
}
|
|
|
|
static struct Qdisc_ops pie_qdisc_ops __read_mostly = {
|
|
.id = "pie",
|
|
.priv_size = sizeof(struct pie_sched_data),
|
|
.enqueue = pie_qdisc_enqueue,
|
|
.dequeue = pie_qdisc_dequeue,
|
|
.peek = qdisc_peek_dequeued,
|
|
.init = pie_init,
|
|
.destroy = pie_destroy,
|
|
.reset = pie_reset,
|
|
.change = pie_change,
|
|
.dump = pie_dump,
|
|
.dump_stats = pie_dump_stats,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init pie_module_init(void)
|
|
{
|
|
return register_qdisc(&pie_qdisc_ops);
|
|
}
|
|
|
|
static void __exit pie_module_exit(void)
|
|
{
|
|
unregister_qdisc(&pie_qdisc_ops);
|
|
}
|
|
|
|
module_init(pie_module_init);
|
|
module_exit(pie_module_exit);
|
|
|
|
MODULE_DESCRIPTION("Proportional Integral controller Enhanced (PIE) scheduler");
|
|
MODULE_AUTHOR("Vijay Subramanian");
|
|
MODULE_AUTHOR("Mythili Prabhu");
|
|
MODULE_LICENSE("GPL");
|