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/*
* Copyright (c) 2010 Fabio Checconi, Luigi Rizzo, Paolo Valente
* 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: release/9.1.0/sys/netinet/ipfw/dn_sched_qfq.c 213253 2010-09-28 22:46:13Z luigi $
*/
#ifdef _KERNEL
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/module.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 <netinet/ipfw/dn_heap.h>
#include <netinet/ipfw/ip_dn_private.h>
#include <netinet/ipfw/dn_sched.h>
#else
#include <dn_test.h>
#endif
#ifdef QFQ_DEBUG
struct qfq_sched;
static void dump_sched(struct qfq_sched *q, const char *msg);
#define NO(x) x
#else
#define NO(x)
#endif
#define DN_SCHED_QFQ 4 // XXX Where?
typedef unsigned long bitmap;
/*
* bitmaps ops are critical. Some linux versions have __fls
* and the bitmap ops. Some machines have ffs
*/
#if defined(_WIN32) || (defined(__MIPSEL__) && defined(LINUX_24))
int fls(unsigned int n)
{
int i = 0;
for (i = 0; n > 0; n >>= 1, i++)
;
return i;
}
#endif
#if !defined(_KERNEL) || defined( __FreeBSD__ ) || defined(_WIN32) || (defined(__MIPSEL__) && defined(LINUX_24))
static inline unsigned long __fls(unsigned long word)
{
return fls(word) - 1;
}
#endif
#if !defined(_KERNEL) || !defined(__linux__)
#ifdef QFQ_DEBUG
int test_bit(int ix, bitmap *p)
{
if (ix < 0 || ix > 31)
D("bad index %d", ix);
return *p & (1<<ix);
}
void __set_bit(int ix, bitmap *p)
{
if (ix < 0 || ix > 31)
D("bad index %d", ix);
*p |= (1<<ix);
}
void __clear_bit(int ix, bitmap *p)
{
if (ix < 0 || ix > 31)
D("bad index %d", ix);
*p &= ~(1<<ix);
}
#else /* !QFQ_DEBUG */
/* XXX do we have fast version, or leave it to the compiler ? */
#define test_bit(ix, pData) ((*pData) & (1<<(ix)))
#define __set_bit(ix, pData) (*pData) |= (1<<(ix))
#define __clear_bit(ix, pData) (*pData) &= ~(1<<(ix))
#endif /* !QFQ_DEBUG */
#endif /* !__linux__ */
#ifdef __MIPSEL__
#define __clear_bit(ix, pData) (*pData) &= ~(1<<(ix))
#endif
/*-------------------------------------------*/
/*
Virtual time computations.
S, F and V are all computed in fixed point arithmetic with
FRAC_BITS decimal bits.
QFQ_MAX_INDEX is the maximum index allowed for a group. We need
one bit per index.
QFQ_MAX_WSHIFT is the maximum power of two supported as a weight.
The layout of the bits is as below:
[ MTU_SHIFT ][ FRAC_BITS ]
[ MAX_INDEX ][ MIN_SLOT_SHIFT ]
^.__grp->index = 0
*.__grp->slot_shift
where MIN_SLOT_SHIFT is derived by difference from the others.
The max group index corresponds to Lmax/w_min, where
Lmax=1<<MTU_SHIFT, w_min = 1 .
From this, and knowing how many groups (MAX_INDEX) we want,
we can derive the shift corresponding to each group.
Because we often need to compute
F = S + len/w_i and V = V + len/wsum
instead of storing w_i store the value
inv_w = (1<<FRAC_BITS)/w_i
so we can do F = S + len * inv_w * wsum.
We use W_TOT in the formulas so we can easily move between
static and adaptive weight sum.
The per-scheduler-instance data contain all the data structures
for the scheduler: bitmaps and bucket lists.
*/
/*
* Maximum number of consecutive slots occupied by backlogged classes
* inside a group. This is approx lmax/lmin + 5.
* XXX check because it poses constraints on MAX_INDEX
*/
#define QFQ_MAX_SLOTS 32
/*
* Shifts used for class<->group mapping. Class weights are
* in the range [1, QFQ_MAX_WEIGHT], we to map each class i to the
* group with the smallest index that can support the L_i / r_i
* configured for the class.
*
* grp->index is the index of the group; and grp->slot_shift
* is the shift for the corresponding (scaled) sigma_i.
*
* When computing the group index, we do (len<<FP_SHIFT)/weight,
* then compute an FLS (which is like a log2()), and if the result
* is below the MAX_INDEX region we use 0 (which is the same as
* using a larger len).
*/
#define QFQ_MAX_INDEX 19
#define QFQ_MAX_WSHIFT 16 /* log2(max_weight) */
#define QFQ_MAX_WEIGHT (1<<QFQ_MAX_WSHIFT)
#define QFQ_MAX_WSUM (2*QFQ_MAX_WEIGHT)
//#define IWSUM (q->i_wsum)
#define IWSUM ((1<<FRAC_BITS)/QFQ_MAX_WSUM)
#define FRAC_BITS 30 /* fixed point arithmetic */
#define ONE_FP (1UL << FRAC_BITS)
#define QFQ_MTU_SHIFT 11 /* log2(max_len) */
#define QFQ_MIN_SLOT_SHIFT (FRAC_BITS + QFQ_MTU_SHIFT - QFQ_MAX_INDEX)
/*
* Possible group states, also indexes for the bitmaps array in
* struct qfq_queue. We rely on ER, IR, EB, IB being numbered 0..3
*/
enum qfq_state { ER, IR, EB, IB, QFQ_MAX_STATE };
struct qfq_group;
/*
* additional queue info. Some of this info should come from
* the flowset, we copy them here for faster processing.
* This is an overlay of the struct dn_queue
*/
struct qfq_class {
struct dn_queue _q;
uint64_t S, F; /* flow timestamps (exact) */
struct qfq_class *next; /* Link for the slot list. */
/* group we belong to. In principle we would need the index,
* which is log_2(lmax/weight), but we never reference it
* directly, only the group.
*/
struct qfq_group *grp;
/* these are copied from the flowset. */
uint32_t inv_w; /* ONE_FP/weight */
uint32_t lmax; /* Max packet size for this flow. */
};
/* Group descriptor, see the paper for details.
* Basically this contains the bucket lists
*/
struct qfq_group {
uint64_t S, F; /* group timestamps (approx). */
unsigned int slot_shift; /* Slot shift. */
unsigned int index; /* Group index. */
unsigned int front; /* Index of the front slot. */
bitmap full_slots; /* non-empty slots */
/* Array of lists of active classes. */
struct qfq_class *slots[QFQ_MAX_SLOTS];
};
/* scheduler instance descriptor. */
struct qfq_sched {
uint64_t V; /* Precise virtual time. */
uint32_t wsum; /* weight sum */
NO(uint32_t i_wsum; /* ONE_FP/w_sum */
uint32_t _queued; /* debugging */
uint32_t loops; /* debugging */)
bitmap bitmaps[QFQ_MAX_STATE]; /* Group bitmaps. */
struct qfq_group groups[QFQ_MAX_INDEX + 1]; /* The groups. */
};
/*---- support functions ----------------------------*/
/* Generic comparison function, handling wraparound. */
static inline int qfq_gt(uint64_t a, uint64_t b)
{
return (int64_t)(a - b) > 0;
}
/* Round a precise timestamp to its slotted value. */
static inline uint64_t qfq_round_down(uint64_t ts, unsigned int shift)
{
return ts & ~((1ULL << shift) - 1);
}
/* return the pointer to the group with lowest index in the bitmap */
static inline struct qfq_group *qfq_ffs(struct qfq_sched *q,
unsigned long bitmap)
{
int index = ffs(bitmap) - 1; // zero-based
return &q->groups[index];
}
/*
* Calculate a flow index, given its weight and maximum packet length.
* index = log_2(maxlen/weight) but we need to apply the scaling.
* This is used only once at flow creation.
*/
static int qfq_calc_index(uint32_t inv_w, unsigned int maxlen)
{
uint64_t slot_size = (uint64_t)maxlen *inv_w;
unsigned long size_map;
int index = 0;
size_map = (unsigned long)(slot_size >> QFQ_MIN_SLOT_SHIFT);
if (!size_map)
goto out;
index = __fls(size_map) + 1; // basically a log_2()
index -= !(slot_size - (1ULL << (index + QFQ_MIN_SLOT_SHIFT - 1)));
if (index < 0)
index = 0;
out:
ND("W = %d, L = %d, I = %d\n", ONE_FP/inv_w, maxlen, index);
return index;
}
/*---- end support functions ----*/
/*-------- API calls --------------------------------*/
/*
* Validate and copy parameters from flowset.
*/
static int
qfq_new_queue(struct dn_queue *_q)
{
struct qfq_sched *q = (struct qfq_sched *)(_q->_si + 1);
struct qfq_class *cl = (struct qfq_class *)_q;
int i;
uint32_t w; /* approximated weight */
/* import parameters from the flowset. They should be correct
* already.
*/
w = _q->fs->fs.par[0];
cl->lmax = _q->fs->fs.par[1];
if (!w || w > QFQ_MAX_WEIGHT) {
w = 1;
D("rounding weight to 1");
}
cl->inv_w = ONE_FP/w;
w = ONE_FP/cl->inv_w;
if (q->wsum + w > QFQ_MAX_WSUM)
return EINVAL;
i = qfq_calc_index(cl->inv_w, cl->lmax);
cl->grp = &q->groups[i];
q->wsum += w;
// XXX cl->S = q->V; ?
// XXX compute q->i_wsum
return 0;
}
/* remove an empty queue */
static int
qfq_free_queue(struct dn_queue *_q)
{
struct qfq_sched *q = (struct qfq_sched *)(_q->_si + 1);
struct qfq_class *cl = (struct qfq_class *)_q;
if (cl->inv_w) {
q->wsum -= ONE_FP/cl->inv_w;
cl->inv_w = 0; /* reset weight to avoid run twice */
}
return 0;
}
/* Calculate a mask to mimic what would be ffs_from(). */
static inline unsigned long
mask_from(unsigned long bitmap, int from)
{
return bitmap & ~((1UL << from) - 1);
}
/*
* The state computation relies on ER=0, IR=1, EB=2, IB=3
* First compute eligibility comparing grp->S, q->V,
* then check if someone is blocking us and possibly add EB
*/
static inline unsigned int
qfq_calc_state(struct qfq_sched *q, struct qfq_group *grp)
{
/* if S > V we are not eligible */
unsigned int state = qfq_gt(grp->S, q->V);
unsigned long mask = mask_from(q->bitmaps[ER], grp->index);
struct qfq_group *next;
if (mask) {
next = qfq_ffs(q, mask);
if (qfq_gt(grp->F, next->F))
state |= EB;
}
return state;
}
/*
* In principle
* q->bitmaps[dst] |= q->bitmaps[src] & mask;
* q->bitmaps[src] &= ~mask;
* but we should make sure that src != dst
*/
static inline void
qfq_move_groups(struct qfq_sched *q, unsigned long mask, int src, int dst)
{
q->bitmaps[dst] |= q->bitmaps[src] & mask;
q->bitmaps[src] &= ~mask;
}
static inline void
qfq_unblock_groups(struct qfq_sched *q, int index, uint64_t old_finish)
{
unsigned long mask = mask_from(q->bitmaps[ER], index + 1);
struct qfq_group *next;
if (mask) {
next = qfq_ffs(q, mask);
if (!qfq_gt(next->F, old_finish))
return;
}
mask = (1UL << index) - 1;
qfq_move_groups(q, mask, EB, ER);
qfq_move_groups(q, mask, IB, IR);
}
/*
* perhaps
*
old_V ^= q->V;
old_V >>= QFQ_MIN_SLOT_SHIFT;
if (old_V) {
...
}
*
*/
static inline void
qfq_make_eligible(struct qfq_sched *q, uint64_t old_V)
{
unsigned long mask, vslot, old_vslot;
vslot = q->V >> QFQ_MIN_SLOT_SHIFT;
old_vslot = old_V >> QFQ_MIN_SLOT_SHIFT;
if (vslot != old_vslot) {
mask = (2UL << (__fls(vslot ^ old_vslot))) - 1;
qfq_move_groups(q, mask, IR, ER);
qfq_move_groups(q, mask, IB, EB);
}
}
/*
* XXX we should make sure that slot becomes less than 32.
* This is guaranteed by the input values.
* roundedS is always cl->S rounded on grp->slot_shift bits.
*/
static inline void
qfq_slot_insert(struct qfq_group *grp, struct qfq_class *cl, uint64_t roundedS)
{
uint64_t slot = (roundedS - grp->S) >> grp->slot_shift;
unsigned int i = (grp->front + slot) % QFQ_MAX_SLOTS;
cl->next = grp->slots[i];
grp->slots[i] = cl;
__set_bit(slot, &grp->full_slots);
}
/*
* remove the entry from the slot
*/
static inline void
qfq_front_slot_remove(struct qfq_group *grp)
{
struct qfq_class **h = &grp->slots[grp->front];
*h = (*h)->next;
if (!*h)
__clear_bit(0, &grp->full_slots);
}
/*
* Returns the first full queue in a group. As a side effect,
* adjust the bucket list so the first non-empty bucket is at
* position 0 in full_slots.
*/
static inline struct qfq_class *
qfq_slot_scan(struct qfq_group *grp)
{
int i;
ND("grp %d full %x", grp->index, grp->full_slots);
if (!grp->full_slots)
return NULL;
i = ffs(grp->full_slots) - 1; // zero-based
if (i > 0) {
grp->front = (grp->front + i) % QFQ_MAX_SLOTS;
grp->full_slots >>= i;
}
return grp->slots[grp->front];
}
/*
* adjust the bucket list. When the start time of a group decreases,
* we move the index down (modulo QFQ_MAX_SLOTS) so we don't need to
* move the objects. The mask of occupied slots must be shifted
* because we use ffs() to find the first non-empty slot.
* This covers decreases in the group's start time, but what about
* increases of the start time ?
* Here too we should make sure that i is less than 32
*/
static inline void
qfq_slot_rotate(struct qfq_sched *q, struct qfq_group *grp, uint64_t roundedS)
{
unsigned int i = (grp->S - roundedS) >> grp->slot_shift;
grp->full_slots <<= i;
grp->front = (grp->front - i) % QFQ_MAX_SLOTS;
}
static inline void
qfq_update_eligible(struct qfq_sched *q, uint64_t old_V)
{
bitmap ineligible;
ineligible = q->bitmaps[IR] | q->bitmaps[IB];
if (ineligible) {
if (!q->bitmaps[ER]) {
struct qfq_group *grp;
grp = qfq_ffs(q, ineligible);
if (qfq_gt(grp->S, q->V))
q->V = grp->S;
}
qfq_make_eligible(q, old_V);
}
}
/*
* Updates the class, returns true if also the group needs to be updated.
*/
static inline int
qfq_update_class(struct qfq_sched *q, struct qfq_group *grp,
struct qfq_class *cl)
{
cl->S = cl->F;
if (cl->_q.mq.head == NULL) {
qfq_front_slot_remove(grp);
} else {
unsigned int len;
uint64_t roundedS;
len = cl->_q.mq.head->m_pkthdr.len;
cl->F = cl->S + (uint64_t)len * cl->inv_w;
roundedS = qfq_round_down(cl->S, grp->slot_shift);
if (roundedS == grp->S)
return 0;
qfq_front_slot_remove(grp);
qfq_slot_insert(grp, cl, roundedS);
}
return 1;
}
static struct mbuf *
qfq_dequeue(struct dn_sch_inst *si)
{
struct qfq_sched *q = (struct qfq_sched *)(si + 1);
struct qfq_group *grp;
struct qfq_class *cl;
struct mbuf *m;
uint64_t old_V;
NO(q->loops++;)
if (!q->bitmaps[ER]) {
NO(if (q->queued)
dump_sched(q, "start dequeue");)
return NULL;
}
grp = qfq_ffs(q, q->bitmaps[ER]);
cl = grp->slots[grp->front];
/* extract from the first bucket in the bucket list */
m = dn_dequeue(&cl->_q);
if (!m) {
D("BUG/* non-workconserving leaf */");
return NULL;
}
NO(q->queued--;)
old_V = q->V;
q->V += (uint64_t)m->m_pkthdr.len * IWSUM;
ND("m is %p F 0x%llx V now 0x%llx", m, cl->F, q->V);
if (qfq_update_class(q, grp, cl)) {
uint64_t old_F = grp->F;
cl = qfq_slot_scan(grp);
if (!cl) { /* group gone, remove from ER */
__clear_bit(grp->index, &q->bitmaps[ER]);
// grp->S = grp->F + 1; // XXX debugging only
} else {
uint64_t roundedS = qfq_round_down(cl->S, grp->slot_shift);
unsigned int s;
if (grp->S == roundedS)
goto skip_unblock;
grp->S = roundedS;
grp->F = roundedS + (2ULL << grp->slot_shift);
/* remove from ER and put in the new set */
__clear_bit(grp->index, &q->bitmaps[ER]);
s = qfq_calc_state(q, grp);
__set_bit(grp->index, &q->bitmaps[s]);
}
/* we need to unblock even if the group has gone away */
qfq_unblock_groups(q, grp->index, old_F);
}
skip_unblock:
qfq_update_eligible(q, old_V);
NO(if (!q->bitmaps[ER] && q->queued)
dump_sched(q, "end dequeue");)
return m;
}
/*
* Assign a reasonable start time for a new flow k in group i.
* Admissible values for \hat(F) are multiples of \sigma_i
* no greater than V+\sigma_i . Larger values mean that
* we had a wraparound so we consider the timestamp to be stale.
*
* If F is not stale and F >= V then we set S = F.
* Otherwise we should assign S = V, but this may violate
* the ordering in ER. So, if we have groups in ER, set S to
* the F_j of the first group j which would be blocking us.
* We are guaranteed not to move S backward because
* otherwise our group i would still be blocked.
*/
static inline void
qfq_update_start(struct qfq_sched *q, struct qfq_class *cl)
{
unsigned long mask;
uint32_t limit, roundedF;
int slot_shift = cl->grp->slot_shift;
roundedF = qfq_round_down(cl->F, slot_shift);
limit = qfq_round_down(q->V, slot_shift) + (1UL << slot_shift);
if (!qfq_gt(cl->F, q->V) || qfq_gt(roundedF, limit)) {
/* timestamp was stale */
mask = mask_from(q->bitmaps[ER], cl->grp->index);
if (mask) {
struct qfq_group *next = qfq_ffs(q, mask);
if (qfq_gt(roundedF, next->F)) {
cl->S = next->F;
return;
}
}
cl->S = q->V;
} else { /* timestamp is not stale */
cl->S = cl->F;
}
}
static int
qfq_enqueue(struct dn_sch_inst *si, struct dn_queue *_q, struct mbuf *m)
{
struct qfq_sched *q = (struct qfq_sched *)(si + 1);
struct qfq_group *grp;
struct qfq_class *cl = (struct qfq_class *)_q;
uint64_t roundedS;
int s;
NO(q->loops++;)
DX(4, "len %d flow %p inv_w 0x%x grp %d", m->m_pkthdr.len,
_q, cl->inv_w, cl->grp->index);
/* XXX verify that the packet obeys the parameters */
if (m != _q->mq.head) {
if (dn_enqueue(_q, m, 0)) /* packet was dropped */
return 1;
NO(q->queued++;)
if (m != _q->mq.head)
return 0;
}
/* If reach this point, queue q was idle */
grp = cl->grp;
qfq_update_start(q, cl); /* adjust start time */
/* compute new finish time and rounded start. */
cl->F = cl->S + (uint64_t)(m->m_pkthdr.len) * cl->inv_w;
roundedS = qfq_round_down(cl->S, grp->slot_shift);
/*
* insert cl in the correct bucket.
* If cl->S >= grp->S we don't need to adjust the
* bucket list and simply go to the insertion phase.
* Otherwise grp->S is decreasing, we must make room
* in the bucket list, and also recompute the group state.
* Finally, if there were no flows in this group and nobody
* was in ER make sure to adjust V.
*/
if (grp->full_slots) {
if (!qfq_gt(grp->S, cl->S))
goto skip_update;
/* create a slot for this cl->S */
qfq_slot_rotate(q, grp, roundedS);
/* group was surely ineligible, remove */
__clear_bit(grp->index, &q->bitmaps[IR]);
__clear_bit(grp->index, &q->bitmaps[IB]);
} else if (!q->bitmaps[ER] && qfq_gt(roundedS, q->V))
q->V = roundedS;
grp->S = roundedS;
grp->F = roundedS + (2ULL << grp->slot_shift); // i.e. 2\sigma_i
s = qfq_calc_state(q, grp);
__set_bit(grp->index, &q->bitmaps[s]);
ND("new state %d 0x%x", s, q->bitmaps[s]);
ND("S %llx F %llx V %llx", cl->S, cl->F, q->V);
skip_update:
qfq_slot_insert(grp, cl, roundedS);
return 0;
}
#if 0
static inline void
qfq_slot_remove(struct qfq_sched *q, struct qfq_group *grp,
struct qfq_class *cl, struct qfq_class **pprev)
{
unsigned int i, offset;
uint64_t roundedS;
roundedS = qfq_round_down(cl->S, grp->slot_shift);
offset = (roundedS - grp->S) >> grp->slot_shift;
i = (grp->front + offset) % QFQ_MAX_SLOTS;
#ifdef notyet
if (!pprev) {
pprev = &grp->slots[i];
while (*pprev && *pprev != cl)
pprev = &(*pprev)->next;
}
#endif
*pprev = cl->next;
if (!grp->slots[i])
__clear_bit(offset, &grp->full_slots);
}
/*
* called to forcibly destroy a queue.
* If the queue is not in the front bucket, or if it has
* other queues in the front bucket, we can simply remove
* the queue with no other side effects.
* Otherwise we must propagate the event up.
* XXX description to be completed.
*/
static void
qfq_deactivate_class(struct qfq_sched *q, struct qfq_class *cl,
struct qfq_class **pprev)
{
struct qfq_group *grp = &q->groups[cl->index];
unsigned long mask;
uint64_t roundedS;
int s;
cl->F = cl->S; // not needed if the class goes away.
qfq_slot_remove(q, grp, cl, pprev);
if (!grp->full_slots) {
/* nothing left in the group, remove from all sets.
* Do ER last because if we were blocking other groups
* we must unblock them.
*/
__clear_bit(grp->index, &q->bitmaps[IR]);
__clear_bit(grp->index, &q->bitmaps[EB]);
__clear_bit(grp->index, &q->bitmaps[IB]);
if (test_bit(grp->index, &q->bitmaps[ER]) &&
!(q->bitmaps[ER] & ~((1UL << grp->index) - 1))) {
mask = q->bitmaps[ER] & ((1UL << grp->index) - 1);
if (mask)
mask = ~((1UL << __fls(mask)) - 1);
else
mask = ~0UL;
qfq_move_groups(q, mask, EB, ER);
qfq_move_groups(q, mask, IB, IR);
}
__clear_bit(grp->index, &q->bitmaps[ER]);
} else if (!grp->slots[grp->front]) {
cl = qfq_slot_scan(grp);
roundedS = qfq_round_down(cl->S, grp->slot_shift);
if (grp->S != roundedS) {
__clear_bit(grp->index, &q->bitmaps[ER]);
__clear_bit(grp->index, &q->bitmaps[IR]);
__clear_bit(grp->index, &q->bitmaps[EB]);
__clear_bit(grp->index, &q->bitmaps[IB]);
grp->S = roundedS;
grp->F = roundedS + (2ULL << grp->slot_shift);
s = qfq_calc_state(q, grp);
__set_bit(grp->index, &q->bitmaps[s]);
}
}
qfq_update_eligible(q, q->V);
}
#endif
static int
qfq_new_fsk(struct dn_fsk *f)
{
ipdn_bound_var(&f->fs.par[0], 1, 1, QFQ_MAX_WEIGHT, "qfq weight");
ipdn_bound_var(&f->fs.par[1], 1500, 1, 2000, "qfq maxlen");
ND("weight %d len %d\n", f->fs.par[0], f->fs.par[1]);
return 0;
}
/*
* initialize a new scheduler instance
*/
static int
qfq_new_sched(struct dn_sch_inst *si)
{
struct qfq_sched *q = (struct qfq_sched *)(si + 1);
struct qfq_group *grp;
int i;
for (i = 0; i <= QFQ_MAX_INDEX; i++) {
grp = &q->groups[i];
grp->index = i;
grp->slot_shift = QFQ_MTU_SHIFT + FRAC_BITS -
(QFQ_MAX_INDEX - i);
}
return 0;
}
/*
* QFQ scheduler descriptor
*/
static struct dn_alg qfq_desc = {
_SI( .type = ) DN_SCHED_QFQ,
_SI( .name = ) "QFQ",
_SI( .flags = ) DN_MULTIQUEUE,
_SI( .schk_datalen = ) 0,
_SI( .si_datalen = ) sizeof(struct qfq_sched),
_SI( .q_datalen = ) sizeof(struct qfq_class) - sizeof(struct dn_queue),
_SI( .enqueue = ) qfq_enqueue,
_SI( .dequeue = ) qfq_dequeue,
_SI( .config = ) NULL,
_SI( .destroy = ) NULL,
_SI( .new_sched = ) qfq_new_sched,
_SI( .free_sched = ) NULL,
_SI( .new_fsk = ) qfq_new_fsk,
_SI( .free_fsk = ) NULL,
_SI( .new_queue = ) qfq_new_queue,
_SI( .free_queue = ) qfq_free_queue,
};
DECLARE_DNSCHED_MODULE(dn_qfq, &qfq_desc);
#ifdef QFQ_DEBUG
static void
dump_groups(struct qfq_sched *q, uint32_t mask)
{
int i, j;
for (i = 0; i < QFQ_MAX_INDEX + 1; i++) {
struct qfq_group *g = &q->groups[i];
if (0 == (mask & (1<<i)))
continue;
for (j = 0; j < QFQ_MAX_SLOTS; j++) {
if (g->slots[j])
D(" bucket %d %p", j, g->slots[j]);
}
D("full_slots 0x%x", g->full_slots);
D(" %2d S 0x%20llx F 0x%llx %c", i,
g->S, g->F,
mask & (1<<i) ? '1' : '0');
}
}
static void
dump_sched(struct qfq_sched *q, const char *msg)
{
D("--- in %s: ---", msg);
ND("loops %d queued %d V 0x%llx", q->loops, q->queued, q->V);
D(" ER 0x%08x", q->bitmaps[ER]);
D(" EB 0x%08x", q->bitmaps[EB]);
D(" IR 0x%08x", q->bitmaps[IR]);
D(" IB 0x%08x", q->bitmaps[IB]);
dump_groups(q, 0xffffffff);
};
#endif /* QFQ_DEBUG */