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sch: make htb_rate_cfg and functions around that generic

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As it is going to be used in tbf as well, push these to generic code.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jiri Pirko 2013-02-12 00:12:03 +00:00 committed by David S. Miller
parent b9a7afdefd
commit 292f1c7ff6
3 changed files with 65 additions and 56 deletions
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19
include/net/sch_generic.h
View File

@ -679,4 +679,23 @@ static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask,
}
#endif
struct psched_ratecfg {
u64 rate_bps;
u32 mult;
u32 shift;
};
static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
unsigned int len)
{
return ((u64)len * r->mult) >> r->shift;
}
extern void psched_ratecfg_precompute(struct psched_ratecfg *r, u32 rate);
static inline u32 psched_ratecfg_getrate(const struct psched_ratecfg *r)
{
return r->rate_bps >> 3;
}
#endif

37
net/sched/sch_generic.c
View File

@ -25,6 +25,7 @@
#include <linux/rcupdate.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/dst.h>
@ -896,3 +897,39 @@ void dev_shutdown(struct net_device *dev)
WARN_ON(timer_pending(&dev->watchdog_timer));
}
void psched_ratecfg_precompute(struct psched_ratecfg *r, u32 rate)
{
u64 factor;
u64 mult;
int shift;
r->rate_bps = rate << 3;
r->shift = 0;
r->mult = 1;
/*
* Calibrate mult, shift so that token counting is accurate
* for smallest packet size (64 bytes). Token (time in ns) is
* computed as (bytes * 8) * NSEC_PER_SEC / rate_bps. It will
* work as long as the smallest packet transfer time can be
* accurately represented in nanosec.
*/
if (r->rate_bps > 0) {
/*
* Higher shift gives better accuracy. Find the largest
* shift such that mult fits in 32 bits.
*/
for (shift = 0; shift < 16; shift++) {
r->shift = shift;
factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);
mult = div64_u64(factor, r->rate_bps);
if (mult > UINT_MAX)
break;
}
r->shift = shift - 1;
factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);
r->mult = div64_u64(factor, r->rate_bps);
}
}
EXPORT_SYMBOL(psched_ratecfg_precompute);

65
net/sched/sch_htb.c
View File

@ -38,6 +38,7 @@
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <net/netlink.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
/* HTB algorithm.
@ -71,12 +72,6 @@ enum htb_cmode {
HTB_CAN_SEND /* class can send */
};
struct htb_rate_cfg {
u64 rate_bps;
u32 mult;
u32 shift;
};
/* interior & leaf nodes; props specific to leaves are marked L: */
struct htb_class {
struct Qdisc_class_common common;
@ -124,8 +119,8 @@ struct htb_class {
int filter_cnt;
/* token bucket parameters */
struct htb_rate_cfg rate;
struct htb_rate_cfg ceil;
struct psched_ratecfg rate;
struct psched_ratecfg ceil;
s64 buffer, cbuffer; /* token bucket depth/rate */
psched_tdiff_t mbuffer; /* max wait time */
s64 tokens, ctokens; /* current number of tokens */
@ -168,45 +163,6 @@ struct htb_sched {
struct work_struct work;
};
static u64 l2t_ns(struct htb_rate_cfg *r, unsigned int len)
{
return ((u64)len * r->mult) >> r->shift;
}
static void htb_precompute_ratedata(struct htb_rate_cfg *r)
{
u64 factor;
u64 mult;
int shift;
r->shift = 0;
r->mult = 1;
/*
* Calibrate mult, shift so that token counting is accurate
* for smallest packet size (64 bytes). Token (time in ns) is
* computed as (bytes * 8) * NSEC_PER_SEC / rate_bps. It will
* work as long as the smallest packet transfer time can be
* accurately represented in nanosec.
*/
if (r->rate_bps > 0) {
/*
* Higher shift gives better accuracy. Find the largest
* shift such that mult fits in 32 bits.
*/
for (shift = 0; shift < 16; shift++) {
r->shift = shift;
factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);
mult = div64_u64(factor, r->rate_bps);
if (mult > UINT_MAX)
break;
}
r->shift = shift - 1;
factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);
r->mult = div64_u64(factor, r->rate_bps);
}
}
/* find class in global hash table using given handle */
static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
{
@ -632,7 +588,7 @@ static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff)
if (toks > cl->buffer)
toks = cl->buffer;
toks -= (s64) l2t_ns(&cl->rate, bytes);
toks -= (s64) psched_l2t_ns(&cl->rate, bytes);
if (toks <= -cl->mbuffer)
toks = 1 - cl->mbuffer;
@ -645,7 +601,7 @@ static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff)
if (toks > cl->cbuffer)
toks = cl->cbuffer;
toks -= (s64) l2t_ns(&cl->ceil, bytes);
toks -= (s64) psched_l2t_ns(&cl->ceil, bytes);
if (toks <= -cl->mbuffer)
toks = 1 - cl->mbuffer;
@ -1134,9 +1090,9 @@ static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
memset(&opt, 0, sizeof(opt));
opt.rate.rate = cl->rate.rate_bps >> 3;
opt.rate.rate = psched_ratecfg_getrate(&cl->rate);
opt.buffer = PSCHED_NS2TICKS(cl->buffer);
opt.ceil.rate = cl->ceil.rate_bps >> 3;
opt.ceil.rate = psched_ratecfg_getrate(&cl->ceil);
opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer);
opt.quantum = cl->quantum;
opt.prio = cl->prio;
@ -1503,11 +1459,8 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
cl->prio = TC_HTB_NUMPRIO - 1;
}
cl->rate.rate_bps = (u64)hopt->rate.rate << 3;
cl->ceil.rate_bps = (u64)hopt->ceil.rate << 3;
htb_precompute_ratedata(&cl->rate);
htb_precompute_ratedata(&cl->ceil);
psched_ratecfg_precompute(&cl->rate, hopt->rate.rate);
psched_ratecfg_precompute(&cl->ceil, hopt->ceil.rate);
cl->buffer = PSCHED_TICKS2NS(hopt->buffer);
cl->cbuffer = PSCHED_TICKS2NS(hopt->buffer);