/* * Copyright (c) 2003 Patrick McHardy, <kaber@trash.net> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * 2003-10-17 - Ported from altq */ /* * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved. * * Permission to use, copy, modify, and distribute this software and * its documentation is hereby granted (including for commercial or * for-profit use), provided that both the copyright notice and this * permission notice appear in all copies of the software, derivative * works, or modified versions, and any portions thereof. * * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF * WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON PROVIDES THIS * SOFTWARE IN ITS ``AS IS'' CONDITION, 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 CARNEGIE MELLON UNIVERSITY 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. * * Carnegie Mellon encourages (but does not require) users of this * software to return any improvements or extensions that they make, * and to grant Carnegie Mellon the rights to redistribute these * changes without encumbrance. */ /* * H-FSC is described in Proceedings of SIGCOMM'97, * "A Hierarchical Fair Service Curve Algorithm for Link-Sharing, * Real-Time and Priority Service" * by Ion Stoica, Hui Zhang, and T. S. Eugene Ng. * * Oleg Cherevko <olwi@aq.ml.com.ua> added the upperlimit for link-sharing. * when a class has an upperlimit, the fit-time is computed from the * upperlimit service curve. the link-sharing scheduler does not schedule * a class whose fit-time exceeds the current time. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/compiler.h> #include <linux/spinlock.h> #include <linux/skbuff.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/rbtree.h> #include <linux/init.h> #include <linux/rtnetlink.h> #include <linux/pkt_sched.h> #include <net/netlink.h> #include <net/pkt_sched.h> #include <net/pkt_cls.h> #include <asm/div64.h> /* * kernel internal service curve representation: * coordinates are given by 64 bit unsigned integers. * x-axis: unit is clock count. * y-axis: unit is byte. * * The service curve parameters are converted to the internal * representation. The slope values are scaled to avoid overflow. * the inverse slope values as well as the y-projection of the 1st * segment are kept in order to avoid 64-bit divide operations * that are expensive on 32-bit architectures. */ struct internal_sc { u64 sm1; /* scaled slope of the 1st segment */ u64 ism1; /* scaled inverse-slope of the 1st segment */ u64 dx; /* the x-projection of the 1st segment */ u64 dy; /* the y-projection of the 1st segment */ u64 sm2; /* scaled slope of the 2nd segment */ u64 ism2; /* scaled inverse-slope of the 2nd segment */ }; /* runtime service curve */ struct runtime_sc { u64 x; /* current starting position on x-axis */ u64 y; /* current starting position on y-axis */ u64 sm1; /* scaled slope of the 1st segment */ u64 ism1; /* scaled inverse-slope of the 1st segment */ u64 dx; /* the x-projection of the 1st segment */ u64 dy; /* the y-projection of the 1st segment */ u64 sm2; /* scaled slope of the 2nd segment */ u64 ism2; /* scaled inverse-slope of the 2nd segment */ }; enum hfsc_class_flags { HFSC_RSC = 0x1, HFSC_FSC = 0x2, HFSC_USC = 0x4 }; struct hfsc_class { struct Qdisc_class_common cl_common; unsigned int refcnt; /* usage count */ struct gnet_stats_basic_packed bstats; struct gnet_stats_queue qstats; struct gnet_stats_rate_est rate_est; unsigned int level; /* class level in hierarchy */ struct tcf_proto *filter_list; /* filter list */ unsigned int filter_cnt; /* filter count */ struct hfsc_sched *sched; /* scheduler data */ struct hfsc_class *cl_parent; /* parent class */ struct list_head siblings; /* sibling classes */ struct list_head children; /* child classes */ struct Qdisc *qdisc; /* leaf qdisc */ struct rb_node el_node; /* qdisc's eligible tree member */ struct rb_root vt_tree; /* active children sorted by cl_vt */ struct rb_node vt_node; /* parent's vt_tree member */ struct rb_root cf_tree; /* active children sorted by cl_f */ struct rb_node cf_node; /* parent's cf_heap member */ struct list_head dlist; /* drop list member */ u64 cl_total; /* total work in bytes */ u64 cl_cumul; /* cumulative work in bytes done by real-time criteria */ u64 cl_d; /* deadline*/ u64 cl_e; /* eligible time */ u64 cl_vt; /* virtual time */ u64 cl_f; /* time when this class will fit for link-sharing, max(myf, cfmin) */ u64 cl_myf; /* my fit-time (calculated from this class's own upperlimit curve) */ u64 cl_myfadj; /* my fit-time adjustment (to cancel history dependence) */ u64 cl_cfmin; /* earliest children's fit-time (used with cl_myf to obtain cl_f) */ u64 cl_cvtmin; /* minimal virtual time among the children fit for link-sharing (monotonic within a period) */ u64 cl_vtadj; /* intra-period cumulative vt adjustment */ u64 cl_vtoff; /* inter-period cumulative vt offset */ u64 cl_cvtmax; /* max child's vt in the last period */ u64 cl_cvtoff; /* cumulative cvtmax of all periods */ u64 cl_pcvtoff; /* parent's cvtoff at initialization time */ struct internal_sc cl_rsc; /* internal real-time service curve */ struct internal_sc cl_fsc; /* internal fair service curve */ struct internal_sc cl_usc; /* internal upperlimit service curve */ struct runtime_sc cl_deadline; /* deadline curve */ struct runtime_sc cl_eligible; /* eligible curve */ struct runtime_sc cl_virtual; /* virtual curve */ struct runtime_sc cl_ulimit; /* upperlimit curve */ unsigned long cl_flags; /* which curves are valid */ unsigned long cl_vtperiod; /* vt period sequence number */ unsigned long cl_parentperiod;/* parent's vt period sequence number*/ unsigned long cl_nactive; /* number of active children */ }; struct hfsc_sched { u16 defcls; /* default class id */ struct hfsc_class root; /* root class */ struct Qdisc_class_hash clhash; /* class hash */ struct rb_root eligible; /* eligible tree */ struct list_head droplist; /* active leaf class list (for dropping) */ struct qdisc_watchdog watchdog; /* watchdog timer */ }; #define HT_INFINITY 0xffffffffffffffffULL /* infinite time value */ /* * eligible tree holds backlogged classes being sorted by their eligible times. * there is one eligible tree per hfsc instance. */ static void eltree_insert(struct hfsc_class *cl) { struct rb_node **p = &cl->sched->eligible.rb_node; struct rb_node *parent = NULL; struct hfsc_class *cl1; while (*p != NULL) { parent = *p; cl1 = rb_entry(parent, struct hfsc_class, el_node); if (cl->cl_e >= cl1->cl_e) p = &parent->rb_right; else p = &parent->rb_left; } rb_link_node(&cl->el_node, parent, p); rb_insert_color(&cl->el_node, &cl->sched->eligible); } static inline void eltree_remove(struct hfsc_class *cl) { rb_erase(&cl->el_node, &cl->sched->eligible); } static inline void eltree_update(struct hfsc_class *cl) { eltree_remove(cl); eltree_insert(cl); } /* find the class with the minimum deadline among the eligible classes */ static inline struct hfsc_class * eltree_get_mindl(struct hfsc_sched *q, u64 cur_time) { struct hfsc_class *p, *cl = NULL; struct rb_node *n; for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) { p = rb_entry(n, struct hfsc_class, el_node); if (p->cl_e > cur_time) break; if (cl == NULL || p->cl_d < cl->cl_d) cl = p; } return cl; } /* find the class with minimum eligible time among the eligible classes */ static inline struct hfsc_class * eltree_get_minel(struct hfsc_sched *q) { struct rb_node *n; n = rb_first(&q->eligible); if (n == NULL) return NULL; return rb_entry(n, struct hfsc_class, el_node); } /* * vttree holds holds backlogged child classes being sorted by their virtual * time. each intermediate class has one vttree. */ static void vttree_insert(struct hfsc_class *cl) { struct rb_node **p = &cl->cl_parent->vt_tree.rb_node; struct rb_node *parent = NULL; struct hfsc_class *cl1; while (*p != NULL) { parent = *p; cl1 = rb_entry(parent, struct hfsc_class, vt_node); if (cl->cl_vt >= cl1->cl_vt) p = &parent->rb_right; else p = &parent->rb_left; } rb_link_node(&cl->vt_node, parent, p); rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree); } static inline void vttree_remove(struct hfsc_class *cl) { rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree); } static inline void vttree_update(struct hfsc_class *cl) { vttree_remove(cl); vttree_insert(cl); } static inline struct hfsc_class * vttree_firstfit(struct hfsc_class *cl, u64 cur_time) { struct hfsc_class *p; struct rb_node *n; for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) { p = rb_entry(n, struct hfsc_class, vt_node); if (p->cl_f <= cur_time) return p; } return NULL; } /* * get the leaf class with the minimum vt in the hierarchy */ static struct hfsc_class * vttree_get_minvt(struct hfsc_class *cl, u64 cur_time) { /* if root-class's cfmin is bigger than cur_time nothing to do */ if (cl->cl_cfmin > cur_time) return NULL; while (cl->level > 0) { cl = vttree_firstfit(cl, cur_time); if (cl == NULL) return NULL; /* * update parent's cl_cvtmin. */ if (cl->cl_parent->cl_cvtmin < cl->cl_vt) cl->cl_parent->cl_cvtmin = cl->cl_vt; } return cl; } static void cftree_insert(struct hfsc_class *cl) { struct rb_node **p = &cl->cl_parent->cf_tree.rb_node; struct rb_node *parent = NULL; struct hfsc_class *cl1; while (*p != NULL) { parent = *p; cl1 = rb_entry(parent, struct hfsc_class, cf_node); if (cl->cl_f >= cl1->cl_f) p = &parent->rb_right; else p = &parent->rb_left; } rb_link_node(&cl->cf_node, parent, p); rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree); } static inline void cftree_remove(struct hfsc_class *cl) { rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree); } static inline void cftree_update(struct hfsc_class *cl) { cftree_remove(cl); cftree_insert(cl); } /* * service curve support functions * * external service curve parameters * m: bps * d: us * internal service curve parameters * sm: (bytes/psched_us) << SM_SHIFT * ism: (psched_us/byte) << ISM_SHIFT * dx: psched_us * * The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us. * * sm and ism are scaled in order to keep effective digits. * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective * digits in decimal using the following table. * * bits/sec 100Kbps 1Mbps 10Mbps 100Mbps 1Gbps * ------------+------------------------------------------------------- * bytes/1.024us 12.8e-3 128e-3 1280e-3 12800e-3 128000e-3 * * 1.024us/byte 78.125 7.8125 0.78125 0.078125 0.0078125 * * So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18. */ #define SM_SHIFT (30 - PSCHED_SHIFT) #define ISM_SHIFT (8 + PSCHED_SHIFT) #define SM_MASK ((1ULL << SM_SHIFT) - 1) #define ISM_MASK ((1ULL << ISM_SHIFT) - 1) static inline u64 seg_x2y(u64 x, u64 sm) { u64 y; /* * compute * y = x * sm >> SM_SHIFT * but divide it for the upper and lower bits to avoid overflow */ y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT); return y; } static inline u64 seg_y2x(u64 y, u64 ism) { u64 x; if (y == 0) x = 0; else if (ism == HT_INFINITY) x = HT_INFINITY; else { x = (y >> ISM_SHIFT) * ism + (((y & ISM_MASK) * ism) >> ISM_SHIFT); } return x; } /* Convert m (bps) into sm (bytes/psched us) */ static u64 m2sm(u32 m) { u64 sm; sm = ((u64)m << SM_SHIFT); sm += PSCHED_TICKS_PER_SEC - 1; do_div(sm, PSCHED_TICKS_PER_SEC); return sm; } /* convert m (bps) into ism (psched us/byte) */ static u64 m2ism(u32 m) { u64 ism; if (m == 0) ism = HT_INFINITY; else { ism = ((u64)PSCHED_TICKS_PER_SEC << ISM_SHIFT); ism += m - 1; do_div(ism, m); } return ism; } /* convert d (us) into dx (psched us) */ static u64 d2dx(u32 d) { u64 dx; dx = ((u64)d * PSCHED_TICKS_PER_SEC); dx += USEC_PER_SEC - 1; do_div(dx, USEC_PER_SEC); return dx; } /* convert sm (bytes/psched us) into m (bps) */ static u32 sm2m(u64 sm) { u64 m; m = (sm * PSCHED_TICKS_PER_SEC) >> SM_SHIFT; return (u32)m; } /* convert dx (psched us) into d (us) */ static u32 dx2d(u64 dx) { u64 d; d = dx * USEC_PER_SEC; do_div(d, PSCHED_TICKS_PER_SEC); return (u32)d; } static void sc2isc(struct tc_service_curve *sc, struct internal_sc *isc) { isc->sm1 = m2sm(sc->m1); isc->ism1 = m2ism(sc->m1); isc->dx = d2dx(sc->d); isc->dy = seg_x2y(isc->dx, isc->sm1); isc->sm2 = m2sm(sc->m2); isc->ism2 = m2ism(sc->m2); } /* * initialize the runtime service curve with the given internal * service curve starting at (x, y). */ static void rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y) { rtsc->x = x; rtsc->y = y; rtsc->sm1 = isc->sm1; rtsc->ism1 = isc->ism1; rtsc->dx = isc->dx; rtsc->dy = isc->dy; rtsc->sm2 = isc->sm2; rtsc->ism2 = isc->ism2; } /* * calculate the y-projection of the runtime service curve by the * given x-projection value */ static u64 rtsc_y2x(struct runtime_sc *rtsc, u64 y) { u64 x; if (y < rtsc->y) x = rtsc->x; else if (y <= rtsc->y + rtsc->dy) { /* x belongs to the 1st segment */ if (rtsc->dy == 0) x = rtsc->x + rtsc->dx; else x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1); } else { /* x belongs to the 2nd segment */ x = rtsc->x + rtsc->dx + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2); } return x; } static u64 rtsc_x2y(struct runtime_sc *rtsc, u64 x) { u64 y; if (x <= rtsc->x) y = rtsc->y; else if (x <= rtsc->x + rtsc->dx) /* y belongs to the 1st segment */ y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1); else /* y belongs to the 2nd segment */ y = rtsc->y + rtsc->dy + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2); return y; } /* * update the runtime service curve by taking the minimum of the current * runtime service curve and the service curve starting at (x, y). */ static void rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y) { u64 y1, y2, dx, dy; u32 dsm; if (isc->sm1 <= isc->sm2) { /* service curve is convex */ y1 = rtsc_x2y(rtsc, x); if (y1 < y) /* the current rtsc is smaller */ return; rtsc->x = x; rtsc->y = y; return; } /* * service curve is concave * compute the two y values of the current rtsc * y1: at x * y2: at (x + dx) */ y1 = rtsc_x2y(rtsc, x); if (y1 <= y) { /* rtsc is below isc, no change to rtsc */ return; } y2 = rtsc_x2y(rtsc, x + isc->dx); if (y2 >= y + isc->dy) { /* rtsc is above isc, replace rtsc by isc */ rtsc->x = x; rtsc->y = y; rtsc->dx = isc->dx; rtsc->dy = isc->dy; return; } /* * the two curves intersect * compute the offsets (dx, dy) using the reverse * function of seg_x2y() * seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y) */ dx = (y1 - y) << SM_SHIFT; dsm = isc->sm1 - isc->sm2; do_div(dx, dsm); /* * check if (x, y1) belongs to the 1st segment of rtsc. * if so, add the offset. */ if (rtsc->x + rtsc->dx > x) dx += rtsc->x + rtsc->dx - x; dy = seg_x2y(dx, isc->sm1); rtsc->x = x; rtsc->y = y; rtsc->dx = dx; rtsc->dy = dy; } static void init_ed(struct hfsc_class *cl, unsigned int next_len) { u64 cur_time = psched_get_time(); /* update the deadline curve */ rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul); /* * update the eligible curve. * for concave, it is equal to the deadline curve. * for convex, it is a linear curve with slope m2. */ cl->cl_eligible = cl->cl_deadline; if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) { cl->cl_eligible.dx = 0; cl->cl_eligible.dy = 0; } /* compute e and d */ cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul); cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len); eltree_insert(cl); } static void update_ed(struct hfsc_class *cl, unsigned int next_len) { cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul); cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len); eltree_update(cl); } static inline void update_d(struct hfsc_class *cl, unsigned int next_len) { cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len); } static inline void update_cfmin(struct hfsc_class *cl) { struct rb_node *n = rb_first(&cl->cf_tree); struct hfsc_class *p; if (n == NULL) { cl->cl_cfmin = 0; return; } p = rb_entry(n, struct hfsc_class, cf_node); cl->cl_cfmin = p->cl_f; } static void init_vf(struct hfsc_class *cl, unsigned int len) { struct hfsc_class *max_cl; struct rb_node *n; u64 vt, f, cur_time; int go_active; cur_time = 0; go_active = 1; for (; cl->cl_parent != NULL; cl = cl->cl_parent) { if (go_active && cl->cl_nactive++ == 0) go_active = 1; else go_active = 0; if (go_active) { n = rb_last(&cl->cl_parent->vt_tree); if (n != NULL) { max_cl = rb_entry(n, struct hfsc_class,vt_node); /* * set vt to the average of the min and max * classes. if the parent's period didn't * change, don't decrease vt of the class. */ vt = max_cl->cl_vt; if (cl->cl_parent->cl_cvtmin != 0) vt = (cl->cl_parent->cl_cvtmin + vt)/2; if (cl->cl_parent->cl_vtperiod != cl->cl_parentperiod || vt > cl->cl_vt) cl->cl_vt = vt; } else { /* * first child for a new parent backlog period. * add parent's cvtmax to cvtoff to make a new * vt (vtoff + vt) larger than the vt in the * last period for all children. */ vt = cl->cl_parent->cl_cvtmax; cl->cl_parent->cl_cvtoff += vt; cl->cl_parent->cl_cvtmax = 0; cl->cl_parent->cl_cvtmin = 0; cl->cl_vt = 0; } cl->cl_vtoff = cl->cl_parent->cl_cvtoff - cl->cl_pcvtoff; /* update the virtual curve */ vt = cl->cl_vt + cl->cl_vtoff; rtsc_min(&cl->cl_virtual, &cl->cl_fsc, vt, cl->cl_total); if (cl->cl_virtual.x == vt) { cl->cl_virtual.x -= cl->cl_vtoff; cl->cl_vtoff = 0; } cl->cl_vtadj = 0; cl->cl_vtperiod++; /* increment vt period */ cl->cl_parentperiod = cl->cl_parent->cl_vtperiod; if (cl->cl_parent->cl_nactive == 0) cl->cl_parentperiod++; cl->cl_f = 0; vttree_insert(cl); cftree_insert(cl); if (cl->cl_flags & HFSC_USC) { /* class has upper limit curve */ if (cur_time == 0) cur_time = psched_get_time(); /* update the ulimit curve */ rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total); /* compute myf */ cl->cl_myf = rtsc_y2x(&cl->cl_ulimit, cl->cl_total); cl->cl_myfadj = 0; } } f = max(cl->cl_myf, cl->cl_cfmin); if (f != cl->cl_f) { cl->cl_f = f; cftree_update(cl); } update_cfmin(cl->cl_parent); } } static void update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time) { u64 f; /* , myf_bound, delta; */ int go_passive = 0; if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC) go_passive = 1; for (; cl->cl_parent != NULL; cl = cl->cl_parent) { cl->cl_total += len; if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0) continue; if (go_passive && --cl->cl_nactive == 0) go_passive = 1; else go_passive = 0; if (go_passive) { /* no more active child, going passive */ /* update cvtmax of the parent class */ if (cl->cl_vt > cl->cl_parent->cl_cvtmax) cl->cl_parent->cl_cvtmax = cl->cl_vt; /* remove this class from the vt tree */ vttree_remove(cl); cftree_remove(cl); update_cfmin(cl->cl_parent); continue; } /* * update vt and f */ cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total) - cl->cl_vtoff + cl->cl_vtadj; /* * if vt of the class is smaller than cvtmin, * the class was skipped in the past due to non-fit. * if so, we need to adjust vtadj. */ if (cl->cl_vt < cl->cl_parent->cl_cvtmin) { cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt; cl->cl_vt = cl->cl_parent->cl_cvtmin; } /* update the vt tree */ vttree_update(cl); if (cl->cl_flags & HFSC_USC) { cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit, cl->cl_total); #if 0 /* * This code causes classes to stay way under their * limit when multiple classes are used at gigabit * speed. needs investigation. -kaber */ /* * if myf lags behind by more than one clock tick * from the current time, adjust myfadj to prevent * a rate-limited class from going greedy. * in a steady state under rate-limiting, myf * fluctuates within one clock tick. */ myf_bound = cur_time - PSCHED_JIFFIE2US(1); if (cl->cl_myf < myf_bound) { delta = cur_time - cl->cl_myf; cl->cl_myfadj += delta; cl->cl_myf += delta; } #endif } f = max(cl->cl_myf, cl->cl_cfmin); if (f != cl->cl_f) { cl->cl_f = f; cftree_update(cl); update_cfmin(cl->cl_parent); } } } static void set_active(struct hfsc_class *cl, unsigned int len) { if (cl->cl_flags & HFSC_RSC) init_ed(cl, len); if (cl->cl_flags & HFSC_FSC) init_vf(cl, len); list_add_tail(&cl->dlist, &cl->sched->droplist); } static void set_passive(struct hfsc_class *cl) { if (cl->cl_flags & HFSC_RSC) eltree_remove(cl); list_del(&cl->dlist); /* * vttree is now handled in update_vf() so that update_vf(cl, 0, 0) * needs to be called explicitly to remove a class from vttree. */ } static unsigned int qdisc_peek_len(struct Qdisc *sch) { struct sk_buff *skb; unsigned int len; skb = sch->ops->peek(sch); if (skb == NULL) { qdisc_warn_nonwc("qdisc_peek_len", sch); return 0; } len = qdisc_pkt_len(skb); return len; } static void hfsc_purge_queue(struct Qdisc *sch, struct hfsc_class *cl) { unsigned int len = cl->qdisc->q.qlen; qdisc_reset(cl->qdisc); qdisc_tree_decrease_qlen(cl->qdisc, len); } static void hfsc_adjust_levels(struct hfsc_class *cl) { struct hfsc_class *p; unsigned int level; do { level = 0; list_for_each_entry(p, &cl->children, siblings) { if (p->level >= level) level = p->level + 1; } cl->level = level; } while ((cl = cl->cl_parent) != NULL); } static inline struct hfsc_class * hfsc_find_class(u32 classid, struct Qdisc *sch) { struct hfsc_sched *q = qdisc_priv(sch); struct Qdisc_class_common *clc; clc = qdisc_class_find(&q->clhash, classid); if (clc == NULL) return NULL; return container_of(clc, struct hfsc_class, cl_common); } static void hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc, u64 cur_time) { sc2isc(rsc, &cl->cl_rsc); rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul); cl->cl_eligible = cl->cl_deadline; if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) { cl->cl_eligible.dx = 0; cl->cl_eligible.dy = 0; } cl->cl_flags |= HFSC_RSC; } static void hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc) { sc2isc(fsc, &cl->cl_fsc); rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total); cl->cl_flags |= HFSC_FSC; } static void hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc, u64 cur_time) { sc2isc(usc, &cl->cl_usc); rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total); cl->cl_flags |= HFSC_USC; } static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = { [TCA_HFSC_RSC] = { .len = sizeof(struct tc_service_curve) }, [TCA_HFSC_FSC] = { .len = sizeof(struct tc_service_curve) }, [TCA_HFSC_USC] = { .len = sizeof(struct tc_service_curve) }, }; static int hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca, unsigned long *arg) { struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *cl = (struct hfsc_class *)*arg; struct hfsc_class *parent = NULL; struct nlattr *opt = tca[TCA_OPTIONS]; struct nlattr *tb[TCA_HFSC_MAX + 1]; struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL; u64 cur_time; int err; if (opt == NULL) return -EINVAL; err = nla_parse_nested(tb, TCA_HFSC_MAX, opt, hfsc_policy); if (err < 0) return err; if (tb[TCA_HFSC_RSC]) { rsc = nla_data(tb[TCA_HFSC_RSC]); if (rsc->m1 == 0 && rsc->m2 == 0) rsc = NULL; } if (tb[TCA_HFSC_FSC]) { fsc = nla_data(tb[TCA_HFSC_FSC]); if (fsc->m1 == 0 && fsc->m2 == 0) fsc = NULL; } if (tb[TCA_HFSC_USC]) { usc = nla_data(tb[TCA_HFSC_USC]); if (usc->m1 == 0 && usc->m2 == 0) usc = NULL; } if (cl != NULL) { if (parentid) { if (cl->cl_parent && cl->cl_parent->cl_common.classid != parentid) return -EINVAL; if (cl->cl_parent == NULL && parentid != TC_H_ROOT) return -EINVAL; } cur_time = psched_get_time(); if (tca[TCA_RATE]) { err = gen_replace_estimator(&cl->bstats, &cl->rate_est, qdisc_root_sleeping_lock(sch), tca[TCA_RATE]); if (err) return err; } sch_tree_lock(sch); if (rsc != NULL) hfsc_change_rsc(cl, rsc, cur_time); if (fsc != NULL) hfsc_change_fsc(cl, fsc); if (usc != NULL) hfsc_change_usc(cl, usc, cur_time); if (cl->qdisc->q.qlen != 0) { if (cl->cl_flags & HFSC_RSC) update_ed(cl, qdisc_peek_len(cl->qdisc)); if (cl->cl_flags & HFSC_FSC) update_vf(cl, 0, cur_time); } sch_tree_unlock(sch); return 0; } if (parentid == TC_H_ROOT) return -EEXIST; parent = &q->root; if (parentid) { parent = hfsc_find_class(parentid, sch); if (parent == NULL) return -ENOENT; } if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0) return -EINVAL; if (hfsc_find_class(classid, sch)) return -EEXIST; if (rsc == NULL && fsc == NULL) return -EINVAL; cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL); if (cl == NULL) return -ENOBUFS; if (tca[TCA_RATE]) { err = gen_new_estimator(&cl->bstats, &cl->rate_est, qdisc_root_sleeping_lock(sch), tca[TCA_RATE]); if (err) { kfree(cl); return err; } } if (rsc != NULL) hfsc_change_rsc(cl, rsc, 0); if (fsc != NULL) hfsc_change_fsc(cl, fsc); if (usc != NULL) hfsc_change_usc(cl, usc, 0); cl->cl_common.classid = classid; cl->refcnt = 1; cl->sched = q; cl->cl_parent = parent; cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid); if (cl->qdisc == NULL) cl->qdisc = &noop_qdisc; INIT_LIST_HEAD(&cl->children); cl->vt_tree = RB_ROOT; cl->cf_tree = RB_ROOT; sch_tree_lock(sch); qdisc_class_hash_insert(&q->clhash, &cl->cl_common); list_add_tail(&cl->siblings, &parent->children); if (parent->level == 0) hfsc_purge_queue(sch, parent); hfsc_adjust_levels(parent); cl->cl_pcvtoff = parent->cl_cvtoff; sch_tree_unlock(sch); qdisc_class_hash_grow(sch, &q->clhash); *arg = (unsigned long)cl; return 0; } static void hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl) { struct hfsc_sched *q = qdisc_priv(sch); tcf_destroy_chain(&cl->filter_list); qdisc_destroy(cl->qdisc); gen_kill_estimator(&cl->bstats, &cl->rate_est); if (cl != &q->root) kfree(cl); } static int hfsc_delete_class(struct Qdisc *sch, unsigned long arg) { struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *cl = (struct hfsc_class *)arg; if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root) return -EBUSY; sch_tree_lock(sch); list_del(&cl->siblings); hfsc_adjust_levels(cl->cl_parent); hfsc_purge_queue(sch, cl); qdisc_class_hash_remove(&q->clhash, &cl->cl_common); BUG_ON(--cl->refcnt == 0); /* * This shouldn't happen: we "hold" one cops->get() when called * from tc_ctl_tclass; the destroy method is done from cops->put(). */ sch_tree_unlock(sch); return 0; } static struct hfsc_class * hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) { struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *head, *cl; struct tcf_result res; struct tcf_proto *tcf; int result; if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 && (cl = hfsc_find_class(skb->priority, sch)) != NULL) if (cl->level == 0) return cl; *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; head = &q->root; tcf = q->root.filter_list; while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) { #ifdef CONFIG_NET_CLS_ACT switch (result) { case TC_ACT_QUEUED: case TC_ACT_STOLEN: *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; case TC_ACT_SHOT: return NULL; } #endif if ((cl = (struct hfsc_class *)res.class) == NULL) { if ((cl = hfsc_find_class(res.classid, sch)) == NULL) break; /* filter selected invalid classid */ if (cl->level >= head->level) break; /* filter may only point downwards */ } if (cl->level == 0) return cl; /* hit leaf class */ /* apply inner filter chain */ tcf = cl->filter_list; head = cl; } /* classification failed, try default class */ cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch); if (cl == NULL || cl->level > 0) return NULL; return cl; } static int hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, struct Qdisc **old) { struct hfsc_class *cl = (struct hfsc_class *)arg; if (cl->level > 0) return -EINVAL; if (new == NULL) { new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, cl->cl_common.classid); if (new == NULL) new = &noop_qdisc; } sch_tree_lock(sch); hfsc_purge_queue(sch, cl); *old = cl->qdisc; cl->qdisc = new; sch_tree_unlock(sch); return 0; } static struct Qdisc * hfsc_class_leaf(struct Qdisc *sch, unsigned long arg) { struct hfsc_class *cl = (struct hfsc_class *)arg; if (cl->level == 0) return cl->qdisc; return NULL; } static void hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg) { struct hfsc_class *cl = (struct hfsc_class *)arg; if (cl->qdisc->q.qlen == 0) { update_vf(cl, 0, 0); set_passive(cl); } } static unsigned long hfsc_get_class(struct Qdisc *sch, u32 classid) { struct hfsc_class *cl = hfsc_find_class(classid, sch); if (cl != NULL) cl->refcnt++; return (unsigned long)cl; } static void hfsc_put_class(struct Qdisc *sch, unsigned long arg) { struct hfsc_class *cl = (struct hfsc_class *)arg; if (--cl->refcnt == 0) hfsc_destroy_class(sch, cl); } static unsigned long hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid) { struct hfsc_class *p = (struct hfsc_class *)parent; struct hfsc_class *cl = hfsc_find_class(classid, sch); if (cl != NULL) { if (p != NULL && p->level <= cl->level) return 0; cl->filter_cnt++; } return (unsigned long)cl; } static void hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg) { struct hfsc_class *cl = (struct hfsc_class *)arg; cl->filter_cnt--; } static struct tcf_proto ** hfsc_tcf_chain(struct Qdisc *sch, unsigned long arg) { struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *cl = (struct hfsc_class *)arg; if (cl == NULL) cl = &q->root; return &cl->filter_list; } static int hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc) { struct tc_service_curve tsc; tsc.m1 = sm2m(sc->sm1); tsc.d = dx2d(sc->dx); tsc.m2 = sm2m(sc->sm2); NLA_PUT(skb, attr, sizeof(tsc), &tsc); return skb->len; nla_put_failure: return -1; } static inline int hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl) { if ((cl->cl_flags & HFSC_RSC) && (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0)) goto nla_put_failure; if ((cl->cl_flags & HFSC_FSC) && (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0)) goto nla_put_failure; if ((cl->cl_flags & HFSC_USC) && (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0)) goto nla_put_failure; return skb->len; nla_put_failure: return -1; } static int hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb, struct tcmsg *tcm) { struct hfsc_class *cl = (struct hfsc_class *)arg; struct nlattr *nest; tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid : TC_H_ROOT; tcm->tcm_handle = cl->cl_common.classid; if (cl->level == 0) tcm->tcm_info = cl->qdisc->handle; nest = nla_nest_start(skb, TCA_OPTIONS); if (nest == NULL) goto nla_put_failure; if (hfsc_dump_curves(skb, cl) < 0) goto nla_put_failure; nla_nest_end(skb, nest); return skb->len; nla_put_failure: nla_nest_cancel(skb, nest); return -EMSGSIZE; } static int hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) { struct hfsc_class *cl = (struct hfsc_class *)arg; struct tc_hfsc_stats xstats; cl->qstats.qlen = cl->qdisc->q.qlen; xstats.level = cl->level; xstats.period = cl->cl_vtperiod; xstats.work = cl->cl_total; xstats.rtwork = cl->cl_cumul; if (gnet_stats_copy_basic(d, &cl->bstats) < 0 || gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 || gnet_stats_copy_queue(d, &cl->qstats) < 0) return -1; return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); } static void hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg) { struct hfsc_sched *q = qdisc_priv(sch); struct hlist_node *n; struct hfsc_class *cl; unsigned int i; if (arg->stop) return; for (i = 0; i < q->clhash.hashsize; i++) { hlist_for_each_entry(cl, n, &q->clhash.hash[i], cl_common.hnode) { if (arg->count < arg->skip) { arg->count++; continue; } if (arg->fn(sch, (unsigned long)cl, arg) < 0) { arg->stop = 1; return; } arg->count++; } } } static void hfsc_schedule_watchdog(struct Qdisc *sch) { struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *cl; u64 next_time = 0; if ((cl = eltree_get_minel(q)) != NULL) next_time = cl->cl_e; if (q->root.cl_cfmin != 0) { if (next_time == 0 || next_time > q->root.cl_cfmin) next_time = q->root.cl_cfmin; } WARN_ON(next_time == 0); qdisc_watchdog_schedule(&q->watchdog, next_time); } static int hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt) { struct hfsc_sched *q = qdisc_priv(sch); struct tc_hfsc_qopt *qopt; int err; if (opt == NULL || nla_len(opt) < sizeof(*qopt)) return -EINVAL; qopt = nla_data(opt); q->defcls = qopt->defcls; err = qdisc_class_hash_init(&q->clhash); if (err < 0) return err; q->eligible = RB_ROOT; INIT_LIST_HEAD(&q->droplist); q->root.cl_common.classid = sch->handle; q->root.refcnt = 1; q->root.sched = q; q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle); if (q->root.qdisc == NULL) q->root.qdisc = &noop_qdisc; INIT_LIST_HEAD(&q->root.children); q->root.vt_tree = RB_ROOT; q->root.cf_tree = RB_ROOT; qdisc_class_hash_insert(&q->clhash, &q->root.cl_common); qdisc_class_hash_grow(sch, &q->clhash); qdisc_watchdog_init(&q->watchdog, sch); return 0; } static int hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt) { struct hfsc_sched *q = qdisc_priv(sch); struct tc_hfsc_qopt *qopt; if (opt == NULL || nla_len(opt) < sizeof(*qopt)) return -EINVAL; qopt = nla_data(opt); sch_tree_lock(sch); q->defcls = qopt->defcls; sch_tree_unlock(sch); return 0; } static void hfsc_reset_class(struct hfsc_class *cl) { cl->cl_total = 0; cl->cl_cumul = 0; cl->cl_d = 0; cl->cl_e = 0; cl->cl_vt = 0; cl->cl_vtadj = 0; cl->cl_vtoff = 0; cl->cl_cvtmin = 0; cl->cl_cvtmax = 0; cl->cl_cvtoff = 0; cl->cl_pcvtoff = 0; cl->cl_vtperiod = 0; cl->cl_parentperiod = 0; cl->cl_f = 0; cl->cl_myf = 0; cl->cl_myfadj = 0; cl->cl_cfmin = 0; cl->cl_nactive = 0; cl->vt_tree = RB_ROOT; cl->cf_tree = RB_ROOT; qdisc_reset(cl->qdisc); if (cl->cl_flags & HFSC_RSC) rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0); if (cl->cl_flags & HFSC_FSC) rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0); if (cl->cl_flags & HFSC_USC) rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0); } static void hfsc_reset_qdisc(struct Qdisc *sch) { struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *cl; struct hlist_node *n; unsigned int i; for (i = 0; i < q->clhash.hashsize; i++) { hlist_for_each_entry(cl, n, &q->clhash.hash[i], cl_common.hnode) hfsc_reset_class(cl); } q->eligible = RB_ROOT; INIT_LIST_HEAD(&q->droplist); qdisc_watchdog_cancel(&q->watchdog); sch->q.qlen = 0; } static void hfsc_destroy_qdisc(struct Qdisc *sch) { struct hfsc_sched *q = qdisc_priv(sch); struct hlist_node *n, *next; struct hfsc_class *cl; unsigned int i; for (i = 0; i < q->clhash.hashsize; i++) { hlist_for_each_entry(cl, n, &q->clhash.hash[i], cl_common.hnode) tcf_destroy_chain(&cl->filter_list); } for (i = 0; i < q->clhash.hashsize; i++) { hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i], cl_common.hnode) hfsc_destroy_class(sch, cl); } qdisc_class_hash_destroy(&q->clhash); qdisc_watchdog_cancel(&q->watchdog); } static int hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb) { struct hfsc_sched *q = qdisc_priv(sch); unsigned char *b = skb_tail_pointer(skb); struct tc_hfsc_qopt qopt; qopt.defcls = q->defcls; NLA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt); return skb->len; nla_put_failure: nlmsg_trim(skb, b); return -1; } static int hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch) { struct hfsc_class *cl; int uninitialized_var(err); cl = hfsc_classify(skb, sch, &err); if (cl == NULL) { if (err & __NET_XMIT_BYPASS) sch->qstats.drops++; kfree_skb(skb); return err; } err = qdisc_enqueue(skb, cl->qdisc); if (unlikely(err != NET_XMIT_SUCCESS)) { if (net_xmit_drop_count(err)) { cl->qstats.drops++; sch->qstats.drops++; } return err; } if (cl->qdisc->q.qlen == 1) set_active(cl, qdisc_pkt_len(skb)); bstats_update(&cl->bstats, skb); sch->q.qlen++; return NET_XMIT_SUCCESS; } static struct sk_buff * hfsc_dequeue(struct Qdisc *sch) { struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *cl; struct sk_buff *skb; u64 cur_time; unsigned int next_len; int realtime = 0; if (sch->q.qlen == 0) return NULL; cur_time = psched_get_time(); /* * if there are eligible classes, use real-time criteria. * find the class with the minimum deadline among * the eligible classes. */ if ((cl = eltree_get_mindl(q, cur_time)) != NULL) { realtime = 1; } else { /* * use link-sharing criteria * get the class with the minimum vt in the hierarchy */ cl = vttree_get_minvt(&q->root, cur_time); if (cl == NULL) { sch->qstats.overlimits++; hfsc_schedule_watchdog(sch); return NULL; } } skb = qdisc_dequeue_peeked(cl->qdisc); if (skb == NULL) { qdisc_warn_nonwc("HFSC", cl->qdisc); return NULL; } update_vf(cl, qdisc_pkt_len(skb), cur_time); if (realtime) cl->cl_cumul += qdisc_pkt_len(skb); if (cl->qdisc->q.qlen != 0) { if (cl->cl_flags & HFSC_RSC) { /* update ed */ next_len = qdisc_peek_len(cl->qdisc); if (realtime) update_ed(cl, next_len); else update_d(cl, next_len); } } else { /* the class becomes passive */ set_passive(cl); } sch->flags &= ~TCQ_F_THROTTLED; qdisc_bstats_update(sch, skb); sch->q.qlen--; return skb; } static unsigned int hfsc_drop(struct Qdisc *sch) { struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *cl; unsigned int len; list_for_each_entry(cl, &q->droplist, dlist) { if (cl->qdisc->ops->drop != NULL && (len = cl->qdisc->ops->drop(cl->qdisc)) > 0) { if (cl->qdisc->q.qlen == 0) { update_vf(cl, 0, 0); set_passive(cl); } else { list_move_tail(&cl->dlist, &q->droplist); } cl->qstats.drops++; sch->qstats.drops++; sch->q.qlen--; return len; } } return 0; } static const struct Qdisc_class_ops hfsc_class_ops = { .change = hfsc_change_class, .delete = hfsc_delete_class, .graft = hfsc_graft_class, .leaf = hfsc_class_leaf, .qlen_notify = hfsc_qlen_notify, .get = hfsc_get_class, .put = hfsc_put_class, .bind_tcf = hfsc_bind_tcf, .unbind_tcf = hfsc_unbind_tcf, .tcf_chain = hfsc_tcf_chain, .dump = hfsc_dump_class, .dump_stats = hfsc_dump_class_stats, .walk = hfsc_walk }; static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = { .id = "hfsc", .init = hfsc_init_qdisc, .change = hfsc_change_qdisc, .reset = hfsc_reset_qdisc, .destroy = hfsc_destroy_qdisc, .dump = hfsc_dump_qdisc, .enqueue = hfsc_enqueue, .dequeue = hfsc_dequeue, .peek = qdisc_peek_dequeued, .drop = hfsc_drop, .cl_ops = &hfsc_class_ops, .priv_size = sizeof(struct hfsc_sched), .owner = THIS_MODULE }; static int __init hfsc_init(void) { return register_qdisc(&hfsc_qdisc_ops); } static void __exit hfsc_cleanup(void) { unregister_qdisc(&hfsc_qdisc_ops); } MODULE_LICENSE("GPL"); module_init(hfsc_init); module_exit(hfsc_cleanup);