fc1de16102
fractional floating point values with integer divides. This will eliminate any chance that the compiler will generate code to evaluate the expression using floating point at runtime. Suggested by: bde Submitted by: Rasool Al-Saadi <ralsaadi@swin.edu.au> MFC after: 8 days (with r300779 and r300949)
154 lines
4.5 KiB
C
154 lines
4.5 KiB
C
/*
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* PIE - Proportional Integral controller Enhanced AQM algorithm.
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*
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* $FreeBSD$
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*
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* Copyright (C) 2016 Centre for Advanced Internet Architectures,
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* Swinburne University of Technology, Melbourne, Australia.
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* Portions of this code were made possible in part by a gift from
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* The Comcast Innovation Fund.
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* Implemented by Rasool Al-Saadi <ralsaadi@swin.edu.au>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef _IP_DN_AQM_PIE_H
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#define _IP_DN_AQM_PIE_H
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#define DN_AQM_PIE 2
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#define PIE_DQ_THRESHOLD_BITS 14
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/* 2^14 =16KB */
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#define PIE_DQ_THRESHOLD (1UL << PIE_DQ_THRESHOLD_BITS)
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#define MEAN_PKTSIZE 800
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/* 31-bits because random() generates range from 0->(2**31)-1 */
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#define PIE_PROB_BITS 31
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#define PIE_MAX_PROB ((1ULL<<PIE_PROB_BITS) -1)
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/* for 16-bits, we have 3-bits for integer part and 13-bits for fraction */
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#define PIE_FIX_POINT_BITS 13
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#define PIE_SCALE (1UL<<PIE_FIX_POINT_BITS)
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/* PIE options */
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enum {
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PIE_ECN_ENABLED =1,
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PIE_CAPDROP_ENABLED = 2,
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PIE_ON_OFF_MODE_ENABLED = 4,
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PIE_DEPRATEEST_ENABLED = 8,
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PIE_DERAND_ENABLED = 16
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};
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/* PIE parameters */
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struct dn_aqm_pie_parms {
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aqm_time_t qdelay_ref; /* AQM Latency Target (default: 15ms) */
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aqm_time_t tupdate; /* a period to calculate drop probability (default:15ms) */
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aqm_time_t max_burst; /* AQM Max Burst Allowance (default: 150ms) */
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uint16_t max_ecnth; /*AQM Max ECN Marking Threshold (default: 10%) */
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uint16_t alpha; /* (default: 1/8) */
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uint16_t beta; /* (default: 1+1/4) */
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uint32_t flags; /* PIE options */
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};
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/* PIE status variables */
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struct pie_status{
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struct callout aqm_pie_callout;
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aqm_time_t burst_allowance;
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uint32_t drop_prob;
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aqm_time_t current_qdelay;
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aqm_time_t qdelay_old;
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uint64_t accu_prob;
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aqm_time_t measurement_start;
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aqm_time_t avg_dq_time;
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uint32_t dq_count;
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uint32_t sflags;
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struct dn_aqm_pie_parms *parms; /* pointer to PIE configurations */
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/* pointer to parent queue of FQ-PIE sub-queues, or queue of owner fs. */
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struct dn_queue *pq;
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struct mtx lock_mtx;
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uint32_t one_third_q_size; /* 1/3 of queue size, for speed optization */
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};
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enum {
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ENQUE = 1,
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DROP,
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MARKECN
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};
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/* PIE current state */
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enum {
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PIE_ACTIVE = 1,
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PIE_INMEASUREMENT = 2
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};
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/*
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* Check if eneque should drop packet to control delay or not based on
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* PIe algorithm.
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* return DROP if it is time to drop or ENQUE otherwise.
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* This function is used by PIE and FQ-PIE.
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*/
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__inline static int
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drop_early(struct pie_status *pst, uint32_t qlen)
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{
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struct dn_aqm_pie_parms *pprms;
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pprms = pst->parms;
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/* queue is not congested */
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if ((pst->qdelay_old < (pprms->qdelay_ref >> 1)
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&& pst->drop_prob < PIE_MAX_PROB / 5 )
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|| qlen <= 2 * MEAN_PKTSIZE)
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return ENQUE;
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if (pst->drop_prob == 0)
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pst->accu_prob = 0;
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/* increment accu_prob */
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if (pprms->flags & PIE_DERAND_ENABLED)
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pst->accu_prob += pst->drop_prob;
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/* De-randomize option
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* if accu_prob < 0.85 -> enqueue
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* if accu_prob>8.5 ->drop
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* between 0.85 and 8.5 || !De-randomize --> drop on prob
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*
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* (0.85 = 17/20 ,8.5 = 17/2)
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*/
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if (pprms->flags & PIE_DERAND_ENABLED) {
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if(pst->accu_prob < (uint64_t) (PIE_MAX_PROB * 17 / 20))
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return ENQUE;
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if( pst->accu_prob >= (uint64_t) (PIE_MAX_PROB * 17 / 2))
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return DROP;
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}
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if (random() < pst->drop_prob) {
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pst->accu_prob = 0;
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return DROP;
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}
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return ENQUE;
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}
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#endif
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