freebsd-dev/sys/netpfil/ipfw/dn_sched_wf2q.c
Pedro F. Giffuni fe267a5590 sys: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:23:17 +00:00

386 lines
12 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2010 Riccardo Panicucci, Universita` di Pisa
* Copyright (c) 2000-2002 Luigi Rizzo, Universita` di Pisa
* All rights reserved
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* $FreeBSD$
*/
#ifdef _KERNEL
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/rwlock.h>
#include <net/if.h> /* IFNAMSIZ */
#include <netinet/in.h>
#include <netinet/ip_var.h> /* ipfw_rule_ref */
#include <netinet/ip_fw.h> /* flow_id */
#include <netinet/ip_dummynet.h>
#include <netpfil/ipfw/ip_fw_private.h>
#include <netpfil/ipfw/dn_heap.h>
#include <netpfil/ipfw/ip_dn_private.h>
#ifdef NEW_AQM
#include <netpfil/ipfw/dn_aqm.h>
#endif
#include <netpfil/ipfw/dn_sched.h>
#else
#include <dn_test.h>
#endif
#ifndef MAX64
#define MAX64(x,y) (( (int64_t) ( (y)-(x) )) > 0 ) ? (y) : (x)
#endif
/*
* timestamps are computed on 64 bit using fixed point arithmetic.
* LMAX_BITS, WMAX_BITS are the max number of bits for the packet len
* and sum of weights, respectively. FRAC_BITS is the number of
* fractional bits. We want FRAC_BITS >> WMAX_BITS to avoid too large
* errors when computing the inverse, FRAC_BITS < 32 so we can do 1/w
* using an unsigned 32-bit division, and to avoid wraparounds we need
* LMAX_BITS + WMAX_BITS + FRAC_BITS << 64
* As an example
* FRAC_BITS = 26, LMAX_BITS=14, WMAX_BITS = 19
*/
#ifndef FRAC_BITS
#define FRAC_BITS 28 /* shift for fixed point arithmetic */
#define ONE_FP (1UL << FRAC_BITS)
#endif
/*
* Private information for the scheduler instance:
* sch_heap (key is Finish time) returns the next queue to serve
* ne_heap (key is Start time) stores not-eligible queues
* idle_heap (key=start/finish time) stores idle flows. It must
* support extract-from-middle.
* A flow is only in 1 of the three heaps.
* XXX todo: use a more efficient data structure, e.g. a tree sorted
* by F with min_subtree(S) in each node
*/
struct wf2qp_si {
struct dn_heap sch_heap; /* top extract - key Finish time */
struct dn_heap ne_heap; /* top extract - key Start time */
struct dn_heap idle_heap; /* random extract - key Start=Finish time */
uint64_t V; /* virtual time */
uint32_t inv_wsum; /* inverse of sum of weights */
uint32_t wsum; /* sum of weights */
};
struct wf2qp_queue {
struct dn_queue _q;
uint64_t S, F; /* start time, finish time */
uint32_t inv_w; /* ONE_FP / weight */
int32_t heap_pos; /* position (index) of struct in heap */
};
/*
* This file implements a WF2Q+ scheduler as it has been in dummynet
* since 2000.
* The scheduler supports per-flow queues and has O(log N) complexity.
*
* WF2Q+ needs to drain entries from the idle heap so that we
* can keep the sum of weights up to date. We can do it whenever
* we get a chance, or periodically, or following some other
* strategy. The function idle_check() drains at most N elements
* from the idle heap.
*/
static void
idle_check(struct wf2qp_si *si, int n, int force)
{
struct dn_heap *h = &si->idle_heap;
while (n-- > 0 && h->elements > 0 &&
(force || DN_KEY_LT(HEAP_TOP(h)->key, si->V))) {
struct dn_queue *q = HEAP_TOP(h)->object;
struct wf2qp_queue *alg_fq = (struct wf2qp_queue *)q;
heap_extract(h, NULL);
/* XXX to let the flowset delete the queue we should
* mark it as 'unused' by the scheduler.
*/
alg_fq->S = alg_fq->F + 1; /* Mark timestamp as invalid. */
si->wsum -= q->fs->fs.par[0]; /* adjust sum of weights */
if (si->wsum > 0)
si->inv_wsum = ONE_FP/si->wsum;
}
}
static int
wf2qp_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
{
struct dn_fsk *fs = q->fs;
struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1);
struct wf2qp_queue *alg_fq;
uint64_t len = m->m_pkthdr.len;
if (m != q->mq.head) {
if (dn_enqueue(q, m, 0)) /* packet was dropped */
return 1;
if (m != q->mq.head) /* queue was already busy */
return 0;
}
/* If reach this point, queue q was idle */
alg_fq = (struct wf2qp_queue *)q;
if (DN_KEY_LT(alg_fq->F, alg_fq->S)) {
/* F<S means timestamps are invalid ->brand new queue. */
alg_fq->S = si->V; /* init start time */
si->wsum += fs->fs.par[0]; /* add weight of new queue. */
si->inv_wsum = ONE_FP/si->wsum;
} else { /* if it was idle then it was in the idle heap */
heap_extract(&si->idle_heap, q);
alg_fq->S = MAX64(alg_fq->F, si->V); /* compute new S */
}
alg_fq->F = alg_fq->S + len * alg_fq->inv_w;
/* if nothing is backlogged, make sure this flow is eligible */
if (si->ne_heap.elements == 0 && si->sch_heap.elements == 0)
si->V = MAX64(alg_fq->S, si->V);
/*
* Look at eligibility. A flow is not eligibile if S>V (when
* this happens, it means that there is some other flow already
* scheduled for the same pipe, so the sch_heap cannot be
* empty). If the flow is not eligible we just store it in the
* ne_heap. Otherwise, we store in the sch_heap.
* Note that for all flows in sch_heap (SCH), S_i <= V,
* and for all flows in ne_heap (NEH), S_i > V.
* So when we need to compute max(V, min(S_i)) forall i in
* SCH+NEH, we only need to look into NEH.
*/
if (DN_KEY_LT(si->V, alg_fq->S)) {
/* S>V means flow Not eligible. */
if (si->sch_heap.elements == 0)
D("++ ouch! not eligible but empty scheduler!");
heap_insert(&si->ne_heap, alg_fq->S, q);
} else {
heap_insert(&si->sch_heap, alg_fq->F, q);
}
return 0;
}
/* XXX invariant: sch > 0 || V >= min(S in neh) */
static struct mbuf *
wf2qp_dequeue(struct dn_sch_inst *_si)
{
/* Access scheduler instance private data */
struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1);
struct mbuf *m;
struct dn_queue *q;
struct dn_heap *sch = &si->sch_heap;
struct dn_heap *neh = &si->ne_heap;
struct wf2qp_queue *alg_fq;
if (sch->elements == 0 && neh->elements == 0) {
/* we have nothing to do. We could kill the idle heap
* altogether and reset V
*/
idle_check(si, 0x7fffffff, 1);
si->V = 0;
si->wsum = 0; /* should be set already */
return NULL; /* quick return if nothing to do */
}
idle_check(si, 1, 0); /* drain something from the idle heap */
/* make sure at least one element is eligible, bumping V
* and moving entries that have become eligible.
* We need to repeat the first part twice, before and
* after extracting the candidate, or enqueue() will
* find the data structure in a wrong state.
*/
m = NULL;
for(;;) {
/*
* Compute V = max(V, min(S_i)). Remember that all elements
* in sch have by definition S_i <= V so if sch is not empty,
* V is surely the max and we must not update it. Conversely,
* if sch is empty we only need to look at neh.
* We don't need to move the queues, as it will be done at the
* next enqueue
*/
if (sch->elements == 0 && neh->elements > 0) {
si->V = MAX64(si->V, HEAP_TOP(neh)->key);
}
while (neh->elements > 0 &&
DN_KEY_LEQ(HEAP_TOP(neh)->key, si->V)) {
q = HEAP_TOP(neh)->object;
alg_fq = (struct wf2qp_queue *)q;
heap_extract(neh, NULL);
heap_insert(sch, alg_fq->F, q);
}
if (m) /* pkt found in previous iteration */
break;
/* ok we have at least one eligible pkt */
q = HEAP_TOP(sch)->object;
alg_fq = (struct wf2qp_queue *)q;
m = dn_dequeue(q);
heap_extract(sch, NULL); /* Remove queue from heap. */
si->V += (uint64_t)(m->m_pkthdr.len) * si->inv_wsum;
alg_fq->S = alg_fq->F; /* Update start time. */
if (q->mq.head == 0) { /* not backlogged any more. */
heap_insert(&si->idle_heap, alg_fq->F, q);
} else { /* Still backlogged. */
/* Update F, store in neh or sch */
uint64_t len = q->mq.head->m_pkthdr.len;
alg_fq->F += len * alg_fq->inv_w;
if (DN_KEY_LEQ(alg_fq->S, si->V)) {
heap_insert(sch, alg_fq->F, q);
} else {
heap_insert(neh, alg_fq->S, q);
}
}
}
return m;
}
static int
wf2qp_new_sched(struct dn_sch_inst *_si)
{
struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1);
int ofs = offsetof(struct wf2qp_queue, heap_pos);
/* all heaps support extract from middle */
if (heap_init(&si->idle_heap, 16, ofs) ||
heap_init(&si->sch_heap, 16, ofs) ||
heap_init(&si->ne_heap, 16, ofs)) {
heap_free(&si->ne_heap);
heap_free(&si->sch_heap);
heap_free(&si->idle_heap);
return ENOMEM;
}
return 0;
}
static int
wf2qp_free_sched(struct dn_sch_inst *_si)
{
struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1);
heap_free(&si->sch_heap);
heap_free(&si->ne_heap);
heap_free(&si->idle_heap);
return 0;
}
static int
wf2qp_new_fsk(struct dn_fsk *fs)
{
ipdn_bound_var(&fs->fs.par[0], 1,
1, 100, "WF2Q+ weight");
return 0;
}
static int
wf2qp_new_queue(struct dn_queue *_q)
{
struct wf2qp_queue *q = (struct wf2qp_queue *)_q;
_q->ni.oid.subtype = DN_SCHED_WF2QP;
q->F = 0; /* not strictly necessary */
q->S = q->F + 1; /* mark timestamp as invalid. */
q->inv_w = ONE_FP / _q->fs->fs.par[0];
if (_q->mq.head != NULL) {
wf2qp_enqueue(_q->_si, _q, _q->mq.head);
}
return 0;
}
/*
* Called when the infrastructure removes a queue (e.g. flowset
* is reconfigured). Nothing to do if we did not 'own' the queue,
* otherwise remove it from the right heap and adjust the sum
* of weights.
*/
static int
wf2qp_free_queue(struct dn_queue *q)
{
struct wf2qp_queue *alg_fq = (struct wf2qp_queue *)q;
struct wf2qp_si *si = (struct wf2qp_si *)(q->_si + 1);
if (alg_fq->S >= alg_fq->F + 1)
return 0; /* nothing to do, not in any heap */
si->wsum -= q->fs->fs.par[0];
if (si->wsum > 0)
si->inv_wsum = ONE_FP/si->wsum;
/* extract from the heap. XXX TODO we may need to adjust V
* to make sure the invariants hold.
*/
if (q->mq.head == NULL) {
heap_extract(&si->idle_heap, q);
} else if (DN_KEY_LT(si->V, alg_fq->S)) {
heap_extract(&si->ne_heap, q);
} else {
heap_extract(&si->sch_heap, q);
}
return 0;
}
/*
* WF2Q+ scheduler descriptor
* contains the type of the scheduler, the name, the size of the
* structures and function pointers.
*/
static struct dn_alg wf2qp_desc = {
_SI( .type = ) DN_SCHED_WF2QP,
_SI( .name = ) "WF2Q+",
_SI( .flags = ) DN_MULTIQUEUE,
/* we need extra space in the si and the queue */
_SI( .schk_datalen = ) 0,
_SI( .si_datalen = ) sizeof(struct wf2qp_si),
_SI( .q_datalen = ) sizeof(struct wf2qp_queue) -
sizeof(struct dn_queue),
_SI( .enqueue = ) wf2qp_enqueue,
_SI( .dequeue = ) wf2qp_dequeue,
_SI( .config = ) NULL,
_SI( .destroy = ) NULL,
_SI( .new_sched = ) wf2qp_new_sched,
_SI( .free_sched = ) wf2qp_free_sched,
_SI( .new_fsk = ) wf2qp_new_fsk,
_SI( .free_fsk = ) NULL,
_SI( .new_queue = ) wf2qp_new_queue,
_SI( .free_queue = ) wf2qp_free_queue,
#ifdef NEW_AQM
_SI( .getconfig = ) NULL,
#endif
};
DECLARE_DNSCHED_MODULE(dn_wf2qp, &wf2qp_desc);