mirror of
https://github.com/Fishwaldo/linux-bl808.git
synced 2025-06-17 20:25:19 +00:00
codel: split into multiple files
It was impossible to include codel.h for the purpose of having access to codel_params or codel_vars structure definitions and using them for embedding in other more complex structures. This splits allows codel.h itself to be treated like any other header file while codel_qdisc.h and codel_impl.h contain function definitions with logic that was previously in codel.h. This copies over copyrights and doesn't involve code changes other than adding a few additional include directives to net/sched/sch*codel.c. Signed-off-by: Michal Kazior <michal.kazior@tieto.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michal Kazior
David S. Miller
parent
79bdc4c862
commit
d068ca2ae2
5 changed files with 332 additions and 223 deletions
|
|
@ -87,27 +87,6 @@ static inline codel_time_t codel_get_time(void)
|
|||
((s32)((a) - (b)) >= 0))
|
||||
#define codel_time_before_eq(a, b) codel_time_after_eq(b, a)
|
||||
|
||||
/* Qdiscs using codel plugin must use codel_skb_cb in their own cb[] */
|
||||
struct codel_skb_cb {
|
||||
codel_time_t enqueue_time;
|
||||
};
|
||||
|
||||
static struct codel_skb_cb *get_codel_cb(const struct sk_buff *skb)
|
||||
{
|
||||
qdisc_cb_private_validate(skb, sizeof(struct codel_skb_cb));
|
||||
return (struct codel_skb_cb *)qdisc_skb_cb(skb)->data;
|
||||
}
|
||||
|
||||
static codel_time_t codel_get_enqueue_time(const struct sk_buff *skb)
|
||||
{
|
||||
return get_codel_cb(skb)->enqueue_time;
|
||||
}
|
||||
|
||||
static void codel_set_enqueue_time(struct sk_buff *skb)
|
||||
{
|
||||
get_codel_cb(skb)->enqueue_time = codel_get_time();
|
||||
}
|
||||
|
||||
static inline u32 codel_time_to_us(codel_time_t val)
|
||||
{
|
||||
u64 valns = ((u64)val << CODEL_SHIFT);
|
||||
|
|
@ -176,212 +155,10 @@ struct codel_stats {
|
|||
|
||||
#define CODEL_DISABLED_THRESHOLD INT_MAX
|
||||
|
||||
static void codel_params_init(struct codel_params *params)
|
||||
{
|
||||
params->interval = MS2TIME(100);
|
||||
params->target = MS2TIME(5);
|
||||
params->ce_threshold = CODEL_DISABLED_THRESHOLD;
|
||||
params->ecn = false;
|
||||
}
|
||||
|
||||
static void codel_vars_init(struct codel_vars *vars)
|
||||
{
|
||||
memset(vars, 0, sizeof(*vars));
|
||||
}
|
||||
|
||||
static void codel_stats_init(struct codel_stats *stats)
|
||||
{
|
||||
stats->maxpacket = 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* http://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Iterative_methods_for_reciprocal_square_roots
|
||||
* new_invsqrt = (invsqrt / 2) * (3 - count * invsqrt^2)
|
||||
*
|
||||
* Here, invsqrt is a fixed point number (< 1.0), 32bit mantissa, aka Q0.32
|
||||
*/
|
||||
static void codel_Newton_step(struct codel_vars *vars)
|
||||
{
|
||||
u32 invsqrt = ((u32)vars->rec_inv_sqrt) << REC_INV_SQRT_SHIFT;
|
||||
u32 invsqrt2 = ((u64)invsqrt * invsqrt) >> 32;
|
||||
u64 val = (3LL << 32) - ((u64)vars->count * invsqrt2);
|
||||
|
||||
val >>= 2; /* avoid overflow in following multiply */
|
||||
val = (val * invsqrt) >> (32 - 2 + 1);
|
||||
|
||||
vars->rec_inv_sqrt = val >> REC_INV_SQRT_SHIFT;
|
||||
}
|
||||
|
||||
/*
|
||||
* CoDel control_law is t + interval/sqrt(count)
|
||||
* We maintain in rec_inv_sqrt the reciprocal value of sqrt(count) to avoid
|
||||
* both sqrt() and divide operation.
|
||||
*/
|
||||
static codel_time_t codel_control_law(codel_time_t t,
|
||||
codel_time_t interval,
|
||||
u32 rec_inv_sqrt)
|
||||
{
|
||||
return t + reciprocal_scale(interval, rec_inv_sqrt << REC_INV_SQRT_SHIFT);
|
||||
}
|
||||
|
||||
typedef u32 (*codel_skb_len_t)(const struct sk_buff *skb);
|
||||
typedef codel_time_t (*codel_skb_time_t)(const struct sk_buff *skb);
|
||||
typedef void (*codel_skb_drop_t)(struct sk_buff *skb, void *ctx);
|
||||
typedef struct sk_buff * (*codel_skb_dequeue_t)(struct codel_vars *vars,
|
||||
void *ctx);
|
||||
|
||||
static bool codel_should_drop(const struct sk_buff *skb,
|
||||
void *ctx,
|
||||
struct codel_vars *vars,
|
||||
struct codel_params *params,
|
||||
struct codel_stats *stats,
|
||||
codel_skb_len_t skb_len_func,
|
||||
codel_skb_time_t skb_time_func,
|
||||
u32 *backlog,
|
||||
codel_time_t now)
|
||||
{
|
||||
bool ok_to_drop;
|
||||
u32 skb_len;
|
||||
|
||||
if (!skb) {
|
||||
vars->first_above_time = 0;
|
||||
return false;
|
||||
}
|
||||
|
||||
skb_len = skb_len_func(skb);
|
||||
vars->ldelay = now - skb_time_func(skb);
|
||||
|
||||
if (unlikely(skb_len > stats->maxpacket))
|
||||
stats->maxpacket = skb_len;
|
||||
|
||||
if (codel_time_before(vars->ldelay, params->target) ||
|
||||
*backlog <= params->mtu) {
|
||||
/* went below - stay below for at least interval */
|
||||
vars->first_above_time = 0;
|
||||
return false;
|
||||
}
|
||||
ok_to_drop = false;
|
||||
if (vars->first_above_time == 0) {
|
||||
/* just went above from below. If we stay above
|
||||
* for at least interval we'll say it's ok to drop
|
||||
*/
|
||||
vars->first_above_time = now + params->interval;
|
||||
} else if (codel_time_after(now, vars->first_above_time)) {
|
||||
ok_to_drop = true;
|
||||
}
|
||||
return ok_to_drop;
|
||||
}
|
||||
|
||||
static struct sk_buff *codel_dequeue(void *ctx,
|
||||
u32 *backlog,
|
||||
struct codel_params *params,
|
||||
struct codel_vars *vars,
|
||||
struct codel_stats *stats,
|
||||
codel_skb_len_t skb_len_func,
|
||||
codel_skb_time_t skb_time_func,
|
||||
codel_skb_drop_t drop_func,
|
||||
codel_skb_dequeue_t dequeue_func)
|
||||
{
|
||||
struct sk_buff *skb = dequeue_func(vars, ctx);
|
||||
codel_time_t now;
|
||||
bool drop;
|
||||
|
||||
if (!skb) {
|
||||
vars->dropping = false;
|
||||
return skb;
|
||||
}
|
||||
now = codel_get_time();
|
||||
drop = codel_should_drop(skb, ctx, vars, params, stats,
|
||||
skb_len_func, skb_time_func, backlog, now);
|
||||
if (vars->dropping) {
|
||||
if (!drop) {
|
||||
/* sojourn time below target - leave dropping state */
|
||||
vars->dropping = false;
|
||||
} else if (codel_time_after_eq(now, vars->drop_next)) {
|
||||
/* It's time for the next drop. Drop the current
|
||||
* packet and dequeue the next. The dequeue might
|
||||
* take us out of dropping state.
|
||||
* If not, schedule the next drop.
|
||||
* A large backlog might result in drop rates so high
|
||||
* that the next drop should happen now,
|
||||
* hence the while loop.
|
||||
*/
|
||||
while (vars->dropping &&
|
||||
codel_time_after_eq(now, vars->drop_next)) {
|
||||
vars->count++; /* dont care of possible wrap
|
||||
* since there is no more divide
|
||||
*/
|
||||
codel_Newton_step(vars);
|
||||
if (params->ecn && INET_ECN_set_ce(skb)) {
|
||||
stats->ecn_mark++;
|
||||
vars->drop_next =
|
||||
codel_control_law(vars->drop_next,
|
||||
params->interval,
|
||||
vars->rec_inv_sqrt);
|
||||
goto end;
|
||||
}
|
||||
stats->drop_len += skb_len_func(skb);
|
||||
drop_func(skb, ctx);
|
||||
stats->drop_count++;
|
||||
skb = dequeue_func(vars, ctx);
|
||||
if (!codel_should_drop(skb, ctx,
|
||||
vars, params, stats,
|
||||
skb_len_func,
|
||||
skb_time_func,
|
||||
backlog, now)) {
|
||||
/* leave dropping state */
|
||||
vars->dropping = false;
|
||||
} else {
|
||||
/* and schedule the next drop */
|
||||
vars->drop_next =
|
||||
codel_control_law(vars->drop_next,
|
||||
params->interval,
|
||||
vars->rec_inv_sqrt);
|
||||
}
|
||||
}
|
||||
}
|
||||
} else if (drop) {
|
||||
u32 delta;
|
||||
|
||||
if (params->ecn && INET_ECN_set_ce(skb)) {
|
||||
stats->ecn_mark++;
|
||||
} else {
|
||||
stats->drop_len += skb_len_func(skb);
|
||||
drop_func(skb, ctx);
|
||||
stats->drop_count++;
|
||||
|
||||
skb = dequeue_func(vars, ctx);
|
||||
drop = codel_should_drop(skb, ctx, vars, params,
|
||||
stats, skb_len_func,
|
||||
skb_time_func, backlog, now);
|
||||
}
|
||||
vars->dropping = true;
|
||||
/* if min went above target close to when we last went below it
|
||||
* assume that the drop rate that controlled the queue on the
|
||||
* last cycle is a good starting point to control it now.
|
||||
*/
|
||||
delta = vars->count - vars->lastcount;
|
||||
if (delta > 1 &&
|
||||
codel_time_before(now - vars->drop_next,
|
||||
16 * params->interval)) {
|
||||
vars->count = delta;
|
||||
/* we dont care if rec_inv_sqrt approximation
|
||||
* is not very precise :
|
||||
* Next Newton steps will correct it quadratically.
|
||||
*/
|
||||
codel_Newton_step(vars);
|
||||
} else {
|
||||
vars->count = 1;
|
||||
vars->rec_inv_sqrt = ~0U >> REC_INV_SQRT_SHIFT;
|
||||
}
|
||||
vars->lastcount = vars->count;
|
||||
vars->drop_next = codel_control_law(now, params->interval,
|
||||
vars->rec_inv_sqrt);
|
||||
}
|
||||
end:
|
||||
if (skb && codel_time_after(vars->ldelay, params->ce_threshold) &&
|
||||
INET_ECN_set_ce(skb))
|
||||
stats->ce_mark++;
|
||||
return skb;
|
||||
}
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue