diff options
Diffstat (limited to 'include/net/codel.h')
| -rw-r--r-- | include/net/codel.h | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/include/net/codel.h b/include/net/codel.h index 550debfc240..fe0eab32ce7 100644 --- a/include/net/codel.h +++ b/include/net/codel.h @@ -46,7 +46,6 @@ #include <linux/skbuff.h> #include <net/pkt_sched.h> #include <net/inet_ecn.h> -#include <linux/reciprocal_div.h> /* Controlling Queue Delay (CoDel) algorithm * ========================================= @@ -72,10 +71,21 @@ static inline codel_time_t codel_get_time(void) return ns >> CODEL_SHIFT; } -#define codel_time_after(a, b) ((s32)(a) - (s32)(b) > 0) -#define codel_time_after_eq(a, b) ((s32)(a) - (s32)(b) >= 0) -#define codel_time_before(a, b) ((s32)(a) - (s32)(b) < 0) -#define codel_time_before_eq(a, b) ((s32)(a) - (s32)(b) <= 0) +/* Dealing with timer wrapping, according to RFC 1982, as desc in wikipedia: + * https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution + * codel_time_after(a,b) returns true if the time a is after time b. + */ +#define codel_time_after(a, b) \ + (typecheck(codel_time_t, a) && \ + typecheck(codel_time_t, b) && \ + ((s32)((a) - (b)) > 0)) +#define codel_time_before(a, b) codel_time_after(b, a) + +#define codel_time_after_eq(a, b) \ + (typecheck(codel_time_t, a) && \ + typecheck(codel_time_t, b) && \ + ((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 { @@ -200,10 +210,9 @@ static codel_time_t codel_control_law(codel_time_t t, codel_time_t interval, u32 rec_inv_sqrt) { - return t + reciprocal_divide(interval, rec_inv_sqrt << REC_INV_SQRT_SHIFT); + return t + reciprocal_scale(interval, rec_inv_sqrt << REC_INV_SQRT_SHIFT); } - static bool codel_should_drop(const struct sk_buff *skb, struct Qdisc *sch, struct codel_vars *vars, @@ -305,6 +314,8 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch, } } } else if (drop) { + u32 delta; + if (params->ecn && INET_ECN_set_ce(skb)) { stats->ecn_mark++; } else { @@ -320,9 +331,11 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch, * assume that the drop rate that controlled the queue on the * last cycle is a good starting point to control it now. */ - if (codel_time_before(now - vars->drop_next, + delta = vars->count - vars->lastcount; + if (delta > 1 && + codel_time_before(now - vars->drop_next, 16 * params->interval)) { - vars->count = (vars->count - vars->lastcount) | 1; + vars->count = delta; /* we dont care if rec_inv_sqrt approximation * is not very precise : * Next Newton steps will correct it quadratically. |