Date: Sun, 31 Jan 2010 12:32:58 +0000 (UTC) From: Luigi Rizzo <luigi@FreeBSD.org> To: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: svn commit: r203283 - in user/luigi/ipfw3-head/sys: conf netinet/ipfw Message-ID: <201001311232.o0VCWwx0024611@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: luigi Date: Sun Jan 31 12:32:57 2010 New Revision: 203283 URL: http://svn.freebsd.org/changeset/base/203283 Log: add a new and very fast fair queueing scheduler with O(1) WFI Added: user/luigi/ipfw3-head/sys/netinet/ipfw/dn_sched_qfq.c (contents, props changed) Modified: user/luigi/ipfw3-head/sys/conf/files Modified: user/luigi/ipfw3-head/sys/conf/files ============================================================================== --- user/luigi/ipfw3-head/sys/conf/files Sun Jan 31 12:31:49 2010 (r203282) +++ user/luigi/ipfw3-head/sys/conf/files Sun Jan 31 12:32:57 2010 (r203283) @@ -2453,6 +2453,7 @@ netinet/ipfw/dn_heap.c optional inet du netinet/ipfw/dn_sched_fifo.c optional inet dummynet netinet/ipfw/dn_sched_rr.c optional inet dummynet netinet/ipfw/dn_sched_wf2q.c optional inet dummynet +netinet/ipfw/dn_sched_qfq.c optional inet dummynet netinet/ipfw/ip_dummynet.c optional inet dummynet netinet/ipfw/ip_dn_io.c optional inet dummynet netinet/ip_ecn.c optional inet | inet6 Added: user/luigi/ipfw3-head/sys/netinet/ipfw/dn_sched_qfq.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ user/luigi/ipfw3-head/sys/netinet/ipfw/dn_sched_qfq.c Sun Jan 31 12:32:57 2010 (r203283) @@ -0,0 +1,849 @@ +/* + * 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. + */ + +#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 uint64_t u64; +typedef unsigned int bitmap; + +#ifndef __FreeBSD__ +static inline unsigned long __fls(unsigned long word) +{ + asm("bsr %1,%0" + : "=r" (word) + : "rm" (word)); + return word; +} +#else +static inline unsigned long __fls(unsigned long word) +{ + return fls(word) - 1; +} +#endif + +#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 */ +/*-------------------------------------------*/ +/* + +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 new_queue + */ +struct qfq_class { + struct new_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 with non-empty slots. Using unsigned long as most + * bitops in Linux use it (i'd rather use u32 or u64 XXX) + */ + bitmap full_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(u64 a, u64 b) +{ + return (int64_t)(a - b) > 0; +} + +/* Round a precise timestamp to its slotted value. */ +static inline u64 qfq_round_down(u64 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) +{ + u64 slot_size = (u64)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 new_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 new_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, u64 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, u64 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, u64 roundedS) +{ + u64 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, u64 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, u64 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; + u64 roundedS; + + len = cl->_q.mq.head->m_pkthdr.len; + cl->F = cl->S + (u64)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 new_sch_inst *si) +{ + struct qfq_sched *q = (struct qfq_sched *)(si + 1); + struct qfq_group *grp; + struct qfq_class *cl; + struct mbuf *m; + u64 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 += (u64)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)) { + u64 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 { + u64 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 new_sch_inst *si, struct new_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; + u64 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 + (u64)(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; + u64 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; + u64 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 new_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 new_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 = { + .type = DN_SCHED_QFQ, + .name = "QFQ", + .flags = DN_MULTIQUEUE, + + .si_datalen = sizeof(struct qfq_sched), + .q_datalen = sizeof(struct qfq_class) - sizeof(struct new_queue), + + .enqueue = qfq_enqueue, + .dequeue = qfq_dequeue, + + .new_sched = qfq_new_sched, + .new_fsk = qfq_new_fsk, + + .new_queue = qfq_new_queue, + .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 */
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201001311232.o0VCWwx0024611>