=============
[PATCH RFC] net_sched: restore "linklayer atm" handling
From: Jesper Dangaard Brouer <brouer@redhat.com>
commit 56b765b79 ("htb: improved accuracy at high rates")
broke the "linklayer atm" handling.
tc class add ... htb rate X ceil Y linklayer atm
This patch restores the "linklayer atm" handling, by using the
__reserved field in struct tc_ratespec, to convey the choosen
linklayer option.
This requires a corrosponding iproute2 tc fix, that updates this
field. Older tc binaries can be detected by the kernel, as the
field would be zero.
Request-For-Comments-by: Jesper Dangaard Brouer <brouer@redhat.com>
---
include/net/sch_generic.h | 8 +++++++-
include/uapi/linux/pkt_sched.h | 11 ++++++++++-
net/sched/sch_generic.c | 4 ++++
3 files changed, 21 insertions(+), 2 deletions(-)
@@ -682,13 +682,18 @@ struct psched_ratecfg {
u64 rate_bps;
u32 mult;
u16 overhead;
+ u8 linklayer;
u8 shift;
};
static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
unsigned int len)
{
- return ((u64)(len + r->overhead) * r->mult) >> r->shift;
+ u64 pkt_len = len + r->overhead;
+
+ if (r->linklayer == TC_LINKLAYER_ATM)
+ pkt_len = DIV_ROUND_UP(pkt_len,48)*53;
+ return (pkt_len * r->mult) >> r->shift;
}
extern void psched_ratecfg_precompute(struct psched_ratecfg *r, const struct tc_ratespec *conf);
@@ -699,6 +704,7 @@ static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
memset(res, 0, sizeof(*res));
res->rate = r->rate_bps >> 3;
res->overhead = r->overhead;
+ res->linklayer = r->linklayer;
}
#endif
@@ -73,9 +73,18 @@ struct tc_estimator {
#define TC_H_ROOT (0xFFFFFFFFU)
#define TC_H_INGRESS (0xFFFFFFF1U)
+/* NOTES: Move to another .h file???
+ * NOTES: Need to corrospond to iproute2 tc/tc_core.h "enum link_layer".
+ */
+enum tc_link_layer {
+ TC_LINKLAYER_UNAWARE, /* Indicate unaware old iproute2 util */
+ TC_LINKLAYER_ETHERNET,
+ TC_LINKLAYER_ATM,
+};
+
struct tc_ratespec {
unsigned char cell_log;
- unsigned char __reserved;
+ __u8 linklayer;
unsigned short overhead;
short cell_align;
unsigned short mpu;
@@ -908,6 +908,10 @@ void psched_ratecfg_precompute(struct psched_ratecfg *r,
memset(r, 0, sizeof(*r));
r->overhead = conf->overhead;
r->rate_bps = (u64)conf->rate << 3;
+ r->linklayer = conf->linklayer;
+ /* We could add a warn once here:
+ * if (r->linklayer == TC_LINKLAYER_UNAWARE)
+ */
r->mult = 1;
/*
* Calibrate mult, shift so that token counting is accurate
IPROUTE2 patch
==============
tc: convey linklayer information to the kernel
From: Jesper Dangaard Brouer <brouer@redhat.com>
---
include/linux/pkt_sched.h | 8 +++++++-
tc/q_htb.c | 2 ++
tc/tc_core.c | 1 +
3 files changed, 10 insertions(+), 1 deletions(-)
@@ -73,9 +73,15 @@ struct tc_estimator {
#define TC_H_ROOT (0xFFFFFFFFU)
#define TC_H_INGRESS (0xFFFFFFF1U)
+enum tc_link_layer {
+ TC_LINKLAYER_UNAWARE, /* Indicate unaware old iproute2 util */
+ TC_LINKLAYER_ETHERNET,
+ TC_LINKLAYER_ATM,
+};
+
struct tc_ratespec {
unsigned char cell_log;
- unsigned char __reserved;
+ __u8 linklayer;
unsigned short overhead;
short cell_align;
unsigned short mpu;
@@ -267,6 +267,8 @@ static int htb_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
buffer = tc_calc_xmitsize(hopt->rate.rate, hopt->buffer);
fprintf(f, "ceil %s ", sprint_rate(hopt->ceil.rate, b1));
cbuffer = tc_calc_xmitsize(hopt->ceil.rate, hopt->cbuffer);
+ // TODO: ADD print statements for linklayer
+
if (show_details) {
fprintf(f, "burst %s/%u mpu %s overhead %s ",
sprint_size(buffer, b1),
@@ -129,6 +129,7 @@ int tc_calc_rtable(struct tc_ratespec *r, __u32 *rtab,
rtab[i] = tc_calc_xmittime(bps, sz);
}
+ r->linklayer = linklayer;
r->cell_align=-1; // Due to the sz calc
r->cell_log=cell_log;
return cell_log;