On 5/16/25 2:01 AM, chia-yu.chang@nokia-bell-labs.com wrote:
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.
v16:
- Update convert_ns_to_usec() to avoid overflow
The changelog should come after the SoB and a '---' separator.
Signed-off-by: Chia-Yu Chang chia-yu.chang@nokia-bell-labs.com
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 ae8af0e8d479..a7243f32ff0f 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 of 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 ffdfb7803e1f..97986c754e47 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); @@ -223,6 +231,15 @@ 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 0xffffffff;
U32_MAX
- else
return lower_32_bits(ns);+}
static enum hrtimer_restart dualpi2_timer(struct hrtimer *timer) { struct dualpi2_sched_data *q = from_timer(q, timer, pi2_timer); @@ -458,6 +475,76 @@ 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 = q->packets_in_c,.packets_in_l = q->packets_in_l,.maxq = q->maxq,.ecn_mark = q->ecn_mark,.credit = q->c_protection_credit,.step_marks = q->step_marks,.memory_used = q->memory_used,.max_memory_used = q->max_memory_used,.memory_limit = q->memory_limit,- };
I *think* you either need READ_ONCE() annotation for the above lockless read, or add a sch_tree_lock(sch)/sch_tree_unlock(sch) pair.
/P