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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/sched/sch_gred.c | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/sched/sch_gred.c')
-rw-r--r-- | net/sched/sch_gred.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c new file mode 100644 index 000000000000..25c171c32715 --- /dev/null +++ b/net/sched/sch_gred.c @@ -0,0 +1,630 @@ +/* + * net/sched/sch_gred.c Generic Random Early Detection queue. + * + * + * 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. + * + * Authors: J Hadi Salim (hadi@cyberus.ca) 1998-2002 + * + * 991129: - Bug fix with grio mode + * - a better sing. AvgQ mode with Grio(WRED) + * - A finer grained VQ dequeue based on sugestion + * from Ren Liu + * - More error checks + * + * + * + * For all the glorious comments look at Alexey's sch_red.c + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <asm/uaccess.h> +#include <asm/system.h> +#include <linux/bitops.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/if_ether.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/notifier.h> +#include <net/ip.h> +#include <net/route.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <net/pkt_sched.h> + +#if 1 /* control */ +#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args) +#else +#define DPRINTK(format,args...) +#endif + +#if 0 /* data */ +#define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args) +#else +#define D2PRINTK(format,args...) +#endif + +struct gred_sched_data; +struct gred_sched; + +struct gred_sched_data +{ +/* Parameters */ + u32 limit; /* HARD maximal queue length */ + u32 qth_min; /* Min average length threshold: A scaled */ + u32 qth_max; /* Max average length threshold: A scaled */ + u32 DP; /* the drop pramaters */ + char Wlog; /* log(W) */ + char Plog; /* random number bits */ + u32 Scell_max; + u32 Rmask; + u32 bytesin; /* bytes seen on virtualQ so far*/ + u32 packetsin; /* packets seen on virtualQ so far*/ + u32 backlog; /* bytes on the virtualQ */ + u32 forced; /* packets dropped for exceeding limits */ + u32 early; /* packets dropped as a warning */ + u32 other; /* packets dropped by invoking drop() */ + u32 pdrop; /* packets dropped because we exceeded physical queue limits */ + char Scell_log; + u8 Stab[256]; + u8 prio; /* the prio of this vq */ + +/* Variables */ + unsigned long qave; /* Average queue length: A scaled */ + int qcount; /* Packets since last random number generation */ + u32 qR; /* Cached random number */ + + psched_time_t qidlestart; /* Start of idle period */ +}; + +struct gred_sched +{ + struct gred_sched_data *tab[MAX_DPs]; + u32 DPs; + u32 def; + u8 initd; + u8 grio; + u8 eqp; +}; + +static int +gred_enqueue(struct sk_buff *skb, struct Qdisc* sch) +{ + psched_time_t now; + struct gred_sched_data *q=NULL; + struct gred_sched *t= qdisc_priv(sch); + unsigned long qave=0; + int i=0; + + if (!t->initd && skb_queue_len(&sch->q) < (sch->dev->tx_queue_len ? : 1)) { + D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n"); + goto do_enqueue; + } + + + if ( ((skb->tc_index&0xf) > (t->DPs -1)) || !(q=t->tab[skb->tc_index&0xf])) { + printk("GRED: setting to default (%d)\n ",t->def); + if (!(q=t->tab[t->def])) { + DPRINTK("GRED: setting to default FAILED! dropping!! " + "(%d)\n ", t->def); + goto drop; + } + /* fix tc_index? --could be controvesial but needed for + requeueing */ + skb->tc_index=(skb->tc_index&0xfffffff0) | t->def; + } + + D2PRINTK("gred_enqueue virtualQ 0x%x classid %x backlog %d " + "general backlog %d\n",skb->tc_index&0xf,sch->handle,q->backlog, + sch->qstats.backlog); + /* sum up all the qaves of prios <= to ours to get the new qave*/ + if (!t->eqp && t->grio) { + for (i=0;i<t->DPs;i++) { + if ((!t->tab[i]) || (i==q->DP)) + continue; + + if ((t->tab[i]->prio < q->prio) && (PSCHED_IS_PASTPERFECT(t->tab[i]->qidlestart))) + qave +=t->tab[i]->qave; + } + + } + + q->packetsin++; + q->bytesin+=skb->len; + + if (t->eqp && t->grio) { + qave=0; + q->qave=t->tab[t->def]->qave; + q->qidlestart=t->tab[t->def]->qidlestart; + } + + if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) { + long us_idle; + PSCHED_GET_TIME(now); + us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max); + PSCHED_SET_PASTPERFECT(q->qidlestart); + + q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF]; + } else { + if (t->eqp) { + q->qave += sch->qstats.backlog - (q->qave >> q->Wlog); + } else { + q->qave += q->backlog - (q->qave >> q->Wlog); + } + + } + + + if (t->eqp && t->grio) + t->tab[t->def]->qave=q->qave; + + if ((q->qave+qave) < q->qth_min) { + q->qcount = -1; +enqueue: + if (q->backlog + skb->len <= q->limit) { + q->backlog += skb->len; +do_enqueue: + __skb_queue_tail(&sch->q, skb); + sch->qstats.backlog += skb->len; + sch->bstats.bytes += skb->len; + sch->bstats.packets++; + return 0; + } else { + q->pdrop++; + } + +drop: + kfree_skb(skb); + sch->qstats.drops++; + return NET_XMIT_DROP; + } + if ((q->qave+qave) >= q->qth_max) { + q->qcount = -1; + sch->qstats.overlimits++; + q->forced++; + goto drop; + } + if (++q->qcount) { + if ((((qave+q->qave) - q->qth_min)>>q->Wlog)*q->qcount < q->qR) + goto enqueue; + q->qcount = 0; + q->qR = net_random()&q->Rmask; + sch->qstats.overlimits++; + q->early++; + goto drop; + } + q->qR = net_random()&q->Rmask; + goto enqueue; +} + +static int +gred_requeue(struct sk_buff *skb, struct Qdisc* sch) +{ + struct gred_sched_data *q; + struct gred_sched *t= qdisc_priv(sch); + q= t->tab[(skb->tc_index&0xf)]; +/* error checking here -- probably unnecessary */ + PSCHED_SET_PASTPERFECT(q->qidlestart); + + __skb_queue_head(&sch->q, skb); + sch->qstats.backlog += skb->len; + sch->qstats.requeues++; + q->backlog += skb->len; + return 0; +} + +static struct sk_buff * +gred_dequeue(struct Qdisc* sch) +{ + struct sk_buff *skb; + struct gred_sched_data *q; + struct gred_sched *t= qdisc_priv(sch); + + skb = __skb_dequeue(&sch->q); + if (skb) { + sch->qstats.backlog -= skb->len; + q= t->tab[(skb->tc_index&0xf)]; + if (q) { + q->backlog -= skb->len; + if (!q->backlog && !t->eqp) + PSCHED_GET_TIME(q->qidlestart); + } else { + D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); + } + return skb; + } + + if (t->eqp) { + q= t->tab[t->def]; + if (!q) + D2PRINTK("no default VQ set: Results will be " + "screwed up\n"); + else + PSCHED_GET_TIME(q->qidlestart); + } + + return NULL; +} + +static unsigned int gred_drop(struct Qdisc* sch) +{ + struct sk_buff *skb; + + struct gred_sched_data *q; + struct gred_sched *t= qdisc_priv(sch); + + skb = __skb_dequeue_tail(&sch->q); + if (skb) { + unsigned int len = skb->len; + sch->qstats.backlog -= len; + sch->qstats.drops++; + q= t->tab[(skb->tc_index&0xf)]; + if (q) { + q->backlog -= len; + q->other++; + if (!q->backlog && !t->eqp) + PSCHED_GET_TIME(q->qidlestart); + } else { + D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); + } + + kfree_skb(skb); + return len; + } + + q=t->tab[t->def]; + if (!q) { + D2PRINTK("no default VQ set: Results might be screwed up\n"); + return 0; + } + + PSCHED_GET_TIME(q->qidlestart); + return 0; + +} + +static void gred_reset(struct Qdisc* sch) +{ + int i; + struct gred_sched_data *q; + struct gred_sched *t= qdisc_priv(sch); + + __skb_queue_purge(&sch->q); + + sch->qstats.backlog = 0; + + for (i=0;i<t->DPs;i++) { + q= t->tab[i]; + if (!q) + continue; + PSCHED_SET_PASTPERFECT(q->qidlestart); + q->qave = 0; + q->qcount = -1; + q->backlog = 0; + q->other=0; + q->forced=0; + q->pdrop=0; + q->early=0; + } +} + +static int gred_change(struct Qdisc *sch, struct rtattr *opt) +{ + struct gred_sched *table = qdisc_priv(sch); + struct gred_sched_data *q; + struct tc_gred_qopt *ctl; + struct tc_gred_sopt *sopt; + struct rtattr *tb[TCA_GRED_STAB]; + struct rtattr *tb2[TCA_GRED_DPS]; + int i; + + if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt)) + return -EINVAL; + + if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) { + rtattr_parse_nested(tb2, TCA_GRED_DPS, opt); + + if (tb2[TCA_GRED_DPS-1] == 0) + return -EINVAL; + + sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]); + table->DPs=sopt->DPs; + table->def=sopt->def_DP; + table->grio=sopt->grio; + table->initd=0; + /* probably need to clear all the table DP entries as well */ + return 0; + } + + + if (!table->DPs || tb[TCA_GRED_PARMS-1] == 0 || tb[TCA_GRED_STAB-1] == 0 || + RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) || + RTA_PAYLOAD(tb[TCA_GRED_STAB-1]) < 256) + return -EINVAL; + + ctl = RTA_DATA(tb[TCA_GRED_PARMS-1]); + if (ctl->DP > MAX_DPs-1 ) { + /* misbehaving is punished! Put in the default drop probability */ + DPRINTK("\nGRED: DP %u not in the proper range fixed. New DP " + "set to default at %d\n",ctl->DP,table->def); + ctl->DP=table->def; + } + + if (table->tab[ctl->DP] == NULL) { + table->tab[ctl->DP]=kmalloc(sizeof(struct gred_sched_data), + GFP_KERNEL); + if (NULL == table->tab[ctl->DP]) + return -ENOMEM; + memset(table->tab[ctl->DP], 0, (sizeof(struct gred_sched_data))); + } + q= table->tab[ctl->DP]; + + if (table->grio) { + if (ctl->prio <=0) { + if (table->def && table->tab[table->def]) { + DPRINTK("\nGRED: DP %u does not have a prio" + "setting default to %d\n",ctl->DP, + table->tab[table->def]->prio); + q->prio=table->tab[table->def]->prio; + } else { + DPRINTK("\nGRED: DP %u does not have a prio" + " setting default to 8\n",ctl->DP); + q->prio=8; + } + } else { + q->prio=ctl->prio; + } + } else { + q->prio=8; + } + + + q->DP=ctl->DP; + q->Wlog = ctl->Wlog; + q->Plog = ctl->Plog; + q->limit = ctl->limit; + q->Scell_log = ctl->Scell_log; + q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL; + q->Scell_max = (255<<q->Scell_log); + q->qth_min = ctl->qth_min<<ctl->Wlog; + q->qth_max = ctl->qth_max<<ctl->Wlog; + q->qave=0; + q->backlog=0; + q->qcount = -1; + q->other=0; + q->forced=0; + q->pdrop=0; + q->early=0; + + PSCHED_SET_PASTPERFECT(q->qidlestart); + memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256); + + if ( table->initd && table->grio) { + /* this looks ugly but it's not in the fast path */ + for (i=0;i<table->DPs;i++) { + if ((!table->tab[i]) || (i==q->DP) ) + continue; + if (table->tab[i]->prio == q->prio ){ + /* WRED mode detected */ + table->eqp=1; + break; + } + } + } + + if (!table->initd) { + table->initd=1; + /* + the first entry also goes into the default until + over-written + */ + + if (table->tab[table->def] == NULL) { + table->tab[table->def]= + kmalloc(sizeof(struct gred_sched_data), GFP_KERNEL); + if (NULL == table->tab[table->def]) + return -ENOMEM; + + memset(table->tab[table->def], 0, + (sizeof(struct gred_sched_data))); + } + q= table->tab[table->def]; + q->DP=table->def; + q->Wlog = ctl->Wlog; + q->Plog = ctl->Plog; + q->limit = ctl->limit; + q->Scell_log = ctl->Scell_log; + q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL; + q->Scell_max = (255<<q->Scell_log); + q->qth_min = ctl->qth_min<<ctl->Wlog; + q->qth_max = ctl->qth_max<<ctl->Wlog; + + if (table->grio) + q->prio=table->tab[ctl->DP]->prio; + else + q->prio=8; + + q->qcount = -1; + PSCHED_SET_PASTPERFECT(q->qidlestart); + memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256); + } + return 0; + +} + +static int gred_init(struct Qdisc *sch, struct rtattr *opt) +{ + struct gred_sched *table = qdisc_priv(sch); + struct tc_gred_sopt *sopt; + struct rtattr *tb[TCA_GRED_STAB]; + struct rtattr *tb2[TCA_GRED_DPS]; + + if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt)) + return -EINVAL; + + if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) { + rtattr_parse_nested(tb2, TCA_GRED_DPS, opt); + + if (tb2[TCA_GRED_DPS-1] == 0) + return -EINVAL; + + sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]); + table->DPs=sopt->DPs; + table->def=sopt->def_DP; + table->grio=sopt->grio; + table->initd=0; + return 0; + } + + DPRINTK("\n GRED_INIT error!\n"); + return -EINVAL; +} + +static int gred_dump(struct Qdisc *sch, struct sk_buff *skb) +{ + unsigned long qave; + struct rtattr *rta; + struct tc_gred_qopt *opt = NULL ; + struct tc_gred_qopt *dst; + struct gred_sched *table = qdisc_priv(sch); + struct gred_sched_data *q; + int i; + unsigned char *b = skb->tail; + + rta = (struct rtattr*)b; + RTA_PUT(skb, TCA_OPTIONS, 0, NULL); + + opt=kmalloc(sizeof(struct tc_gred_qopt)*MAX_DPs, GFP_KERNEL); + + if (opt == NULL) { + DPRINTK("gred_dump:failed to malloc for %Zd\n", + sizeof(struct tc_gred_qopt)*MAX_DPs); + goto rtattr_failure; + } + + memset(opt, 0, (sizeof(struct tc_gred_qopt))*table->DPs); + + if (!table->initd) { + DPRINTK("NO GRED Queues setup!\n"); + } + + for (i=0;i<MAX_DPs;i++) { + dst= &opt[i]; + q= table->tab[i]; + + if (!q) { + /* hack -- fix at some point with proper message + This is how we indicate to tc that there is no VQ + at this DP */ + + dst->DP=MAX_DPs+i; + continue; + } + + dst->limit=q->limit; + dst->qth_min=q->qth_min>>q->Wlog; + dst->qth_max=q->qth_max>>q->Wlog; + dst->DP=q->DP; + dst->backlog=q->backlog; + if (q->qave) { + if (table->eqp && table->grio) { + q->qidlestart=table->tab[table->def]->qidlestart; + q->qave=table->tab[table->def]->qave; + } + if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) { + long idle; + psched_time_t now; + PSCHED_GET_TIME(now); + idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max); + qave = q->qave >> q->Stab[(idle>>q->Scell_log)&0xFF]; + dst->qave = qave >> q->Wlog; + + } else { + dst->qave = q->qave >> q->Wlog; + } + } else { + dst->qave = 0; + } + + + dst->Wlog = q->Wlog; + dst->Plog = q->Plog; + dst->Scell_log = q->Scell_log; + dst->other = q->other; + dst->forced = q->forced; + dst->early = q->early; + dst->pdrop = q->pdrop; + dst->prio = q->prio; + dst->packets=q->packetsin; + dst->bytesin=q->bytesin; + } + + RTA_PUT(skb, TCA_GRED_PARMS, sizeof(struct tc_gred_qopt)*MAX_DPs, opt); + rta->rta_len = skb->tail - b; + + kfree(opt); + return skb->len; + +rtattr_failure: + if (opt) + kfree(opt); + DPRINTK("gred_dump: FAILURE!!!!\n"); + +/* also free the opt struct here */ + skb_trim(skb, b - skb->data); + return -1; +} + +static void gred_destroy(struct Qdisc *sch) +{ + struct gred_sched *table = qdisc_priv(sch); + int i; + + for (i = 0;i < table->DPs; i++) { + if (table->tab[i]) + kfree(table->tab[i]); + } +} + +static struct Qdisc_ops gred_qdisc_ops = { + .next = NULL, + .cl_ops = NULL, + .id = "gred", + .priv_size = sizeof(struct gred_sched), + .enqueue = gred_enqueue, + .dequeue = gred_dequeue, + .requeue = gred_requeue, + .drop = gred_drop, + .init = gred_init, + .reset = gred_reset, + .destroy = gred_destroy, + .change = gred_change, + .dump = gred_dump, + .owner = THIS_MODULE, +}; + +static int __init gred_module_init(void) +{ + return register_qdisc(&gred_qdisc_ops); +} +static void __exit gred_module_exit(void) +{ + unregister_qdisc(&gred_qdisc_ops); +} +module_init(gred_module_init) +module_exit(gred_module_exit) +MODULE_LICENSE("GPL"); |