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a4a710c4a7
Change PSCHED_SHIFT from 10 to 6 to increase schedulers time resolution. This will increase 16x a number of (internal) ticks per nanosecond, and is needed to improve accuracy of schedulers based on rate tables, like HTB, TBF or CBQ, with rates above 100Mbit. It is assumed this change is safe for 32bit accounting of time diffs up to 2 minutes, which should be enough for common use (extremely low rate values may overflow, so get inaccurate instead). To make full use of this change an updated iproute2 will be needed. (But using older iproute2 should be safe too.) This change breaks ticks - microseconds similarity, so some minor code fixes might be needed. It is also planned to change naming adequately eg. to PSCHED_TICKS2NS() etc. in the near future. Reported-by: Antonio Almeida <vexwek@gmail.com> Tested-by: Antonio Almeida <vexwek@gmail.com> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
113 lines
3.1 KiB
C
113 lines
3.1 KiB
C
#ifndef __NET_PKT_SCHED_H
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#define __NET_PKT_SCHED_H
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#include <linux/jiffies.h>
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#include <linux/ktime.h>
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#include <net/sch_generic.h>
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struct qdisc_walker
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{
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int stop;
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int skip;
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int count;
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int (*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
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};
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#define QDISC_ALIGNTO 32
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#define QDISC_ALIGN(len) (((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
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static inline void *qdisc_priv(struct Qdisc *q)
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{
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return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
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}
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/*
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Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
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Normal IP packet size ~ 512byte, hence:
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0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
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10Mbit ethernet.
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10msec resolution -> <50Kbit/sec.
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The result: [34]86 is not good choice for QoS router :-(
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The things are not so bad, because we may use artifical
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clock evaluated by integration of network data flow
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in the most critical places.
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*/
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typedef u64 psched_time_t;
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typedef long psched_tdiff_t;
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/* Avoid doing 64 bit divide */
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#define PSCHED_SHIFT 6
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#define PSCHED_US2NS(x) ((s64)(x) << PSCHED_SHIFT)
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#define PSCHED_NS2US(x) ((x) >> PSCHED_SHIFT)
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#define PSCHED_TICKS_PER_SEC PSCHED_NS2US(NSEC_PER_SEC)
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#define PSCHED_PASTPERFECT 0
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static inline psched_time_t psched_get_time(void)
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{
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return PSCHED_NS2US(ktime_to_ns(ktime_get()));
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}
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static inline psched_tdiff_t
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psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
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{
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return min(tv1 - tv2, bound);
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}
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struct qdisc_watchdog {
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struct hrtimer timer;
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struct Qdisc *qdisc;
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};
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extern void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
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extern void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
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psched_time_t expires);
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extern void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
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extern struct Qdisc_ops pfifo_qdisc_ops;
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extern struct Qdisc_ops bfifo_qdisc_ops;
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extern int fifo_set_limit(struct Qdisc *q, unsigned int limit);
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extern struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
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unsigned int limit);
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extern int register_qdisc(struct Qdisc_ops *qops);
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extern int unregister_qdisc(struct Qdisc_ops *qops);
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extern void qdisc_list_del(struct Qdisc *q);
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extern struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
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extern struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
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extern struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
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struct nlattr *tab);
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extern void qdisc_put_rtab(struct qdisc_rate_table *tab);
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extern void qdisc_put_stab(struct qdisc_size_table *tab);
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extern void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc);
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extern void __qdisc_run(struct Qdisc *q);
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static inline void qdisc_run(struct Qdisc *q)
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{
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if (!test_and_set_bit(__QDISC_STATE_RUNNING, &q->state))
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__qdisc_run(q);
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}
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extern int tc_classify_compat(struct sk_buff *skb, struct tcf_proto *tp,
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struct tcf_result *res);
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extern int tc_classify(struct sk_buff *skb, struct tcf_proto *tp,
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struct tcf_result *res);
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/* Calculate maximal size of packet seen by hard_start_xmit
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routine of this device.
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*/
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static inline unsigned psched_mtu(const struct net_device *dev)
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{
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return dev->mtu + dev->hard_header_len;
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}
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#endif
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