From: Chia-Yu Chang chia-yu.chang@nokia-bell-labs.com
The configuration and statistics dump of the DualPI2 Qdisc provides information related to both queues, such as packet numbers and queuing delays in the L-queue and C-queue, as well as general information such as probability value, WRR credits, memory usage, packet marking counters, max queue size, etc.
The following patch includes enqueue/dequeue for DualPI2.
Signed-off-by: Chia-Yu Chang chia-yu.chang@nokia-bell-labs.com
--- v18: - Fix typo in the comment
v17: - Replace 0xffffffff with U32_MAX - Add READ_ONCE() in dualpi2_dump_stats()
v16: - Update convert_ns_to_usec() to avoid overflow --- include/uapi/linux/pkt_sched.h | 15 ++++++ net/sched/sch_dualpi2.c | 89 ++++++++++++++++++++++++++++++++++ 2 files changed, 104 insertions(+)
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index 11ec95f3461f..34fc0e2150ac 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -1264,4 +1264,19 @@ enum {
#define TCA_DUALPI2_MAX (__TCA_DUALPI2_MAX - 1)
+struct tc_dualpi2_xstats { + __u32 prob; /* current probability */ + __u32 delay_c; /* current delay in C queue */ + __u32 delay_l; /* current delay in L queue */ + __u32 packets_in_c; /* number of packets enqueued in C queue */ + __u32 packets_in_l; /* number of packets enqueued in L queue */ + __u32 maxq; /* maximum queue size */ + __u32 ecn_mark; /* packets marked with ecn*/ + __u32 step_marks; /* ECN marks due to the step AQM */ + __s32 credit; /* current c_protection credit */ + __u32 memory_used; /* Memory used by both queues */ + __u32 max_memory_used; /* Maximum used memory */ + __u32 memory_limit; /* Memory limit of both queues */ +}; + #endif diff --git a/net/sched/sch_dualpi2.c b/net/sched/sch_dualpi2.c index aa0d04754c9e..978676451e2f 100644 --- a/net/sched/sch_dualpi2.c +++ b/net/sched/sch_dualpi2.c @@ -123,6 +123,14 @@ static u32 dualpi2_scale_alpha_beta(u32 param) return tmp; }
+static u32 dualpi2_unscale_alpha_beta(u32 param) +{ + u64 tmp = ((u64)param * NSEC_PER_SEC << ALPHA_BETA_SCALING); + + do_div(tmp, MAX_PROB); + return tmp; +} + static ktime_t next_pi2_timeout(struct dualpi2_sched_data *q) { return ktime_add_ns(ktime_get_ns(), q->pi2_tupdate); @@ -227,6 +235,15 @@ static u32 convert_us_to_nsec(u32 us) return lower_32_bits(ns); }
+static u32 convert_ns_to_usec(u64 ns) +{ + do_div(ns, NSEC_PER_USEC); + if (upper_32_bits(ns)) + return U32_MAX; + else + return lower_32_bits(ns); +} + static enum hrtimer_restart dualpi2_timer(struct hrtimer *timer) { struct dualpi2_sched_data *q = timer_container_of(q, timer, pi2_timer); @@ -462,6 +479,76 @@ static int dualpi2_init(struct Qdisc *sch, struct nlattr *opt, return 0; }
+static int dualpi2_dump(struct Qdisc *sch, struct sk_buff *skb) +{ + struct dualpi2_sched_data *q = qdisc_priv(sch); + struct nlattr *opts; + + opts = nla_nest_start_noflag(skb, TCA_OPTIONS); + if (!opts) + goto nla_put_failure; + + if (nla_put_u32(skb, TCA_DUALPI2_LIMIT, READ_ONCE(sch->limit)) || + nla_put_u32(skb, TCA_DUALPI2_MEMORY_LIMIT, + READ_ONCE(q->memory_limit)) || + nla_put_u32(skb, TCA_DUALPI2_TARGET, + convert_ns_to_usec(READ_ONCE(q->pi2_target))) || + nla_put_u32(skb, TCA_DUALPI2_TUPDATE, + convert_ns_to_usec(READ_ONCE(q->pi2_tupdate))) || + nla_put_u32(skb, TCA_DUALPI2_ALPHA, + dualpi2_unscale_alpha_beta(READ_ONCE(q->pi2_alpha))) || + nla_put_u32(skb, TCA_DUALPI2_BETA, + dualpi2_unscale_alpha_beta(READ_ONCE(q->pi2_beta))) || + nla_put_u32(skb, TCA_DUALPI2_STEP_THRESH, + READ_ONCE(q->step_in_packets) ? + READ_ONCE(q->step_thresh) : + convert_ns_to_usec(READ_ONCE(q->step_thresh))) || + nla_put_u32(skb, TCA_DUALPI2_MIN_QLEN_STEP, + READ_ONCE(q->min_qlen_step)) || + nla_put_u8(skb, TCA_DUALPI2_COUPLING, + READ_ONCE(q->coupling_factor)) || + nla_put_u8(skb, TCA_DUALPI2_DROP_OVERLOAD, + READ_ONCE(q->drop_overload)) || + (READ_ONCE(q->step_in_packets) && + nla_put_flag(skb, TCA_DUALPI2_STEP_PACKETS)) || + nla_put_u8(skb, TCA_DUALPI2_DROP_EARLY, + READ_ONCE(q->drop_early)) || + nla_put_u8(skb, TCA_DUALPI2_C_PROTECTION, + READ_ONCE(q->c_protection_wc)) || + nla_put_u8(skb, TCA_DUALPI2_ECN_MASK, READ_ONCE(q->ecn_mask)) || + nla_put_u8(skb, TCA_DUALPI2_SPLIT_GSO, READ_ONCE(q->split_gso))) + goto nla_put_failure; + + return nla_nest_end(skb, opts); + +nla_put_failure: + nla_nest_cancel(skb, opts); + return -1; +} + +static int dualpi2_dump_stats(struct Qdisc *sch, struct gnet_dump *d) +{ + struct dualpi2_sched_data *q = qdisc_priv(sch); + struct tc_dualpi2_xstats st = { + .prob = READ_ONCE(q->pi2_prob), + .packets_in_c = READ_ONCE(q->packets_in_c), + .packets_in_l = READ_ONCE(q->packets_in_l), + .maxq = READ_ONCE(q->maxq), + .ecn_mark = READ_ONCE(q->ecn_mark), + .credit = READ_ONCE(q->c_protection_credit), + .step_marks = READ_ONCE(q->step_marks), + .memory_used = READ_ONCE(q->memory_used), + .max_memory_used = READ_ONCE(q->max_memory_used), + .memory_limit = READ_ONCE(q->memory_limit), + }; + u64 qc, ql; + + get_queue_delays(q, &qc, &ql); + st.delay_l = convert_ns_to_usec(ql); + st.delay_c = convert_ns_to_usec(qc); + return gnet_stats_copy_app(d, &st, sizeof(st)); +} + /* Reset both L-queue and C-queue, internal packet counters, PI probability, * C-queue protection credit, and timestamps, while preserving current * configuration of DUALPI2. @@ -566,6 +653,8 @@ static struct Qdisc_ops dualpi2_qdisc_ops __read_mostly = { .destroy = dualpi2_destroy, .reset = dualpi2_reset, .change = dualpi2_change, + .dump = dualpi2_dump, + .dump_stats = dualpi2_dump_stats, .owner = THIS_MODULE, };