+++ /dev/null
-From: Eric Dumazet <edumazet@google.com>
-Date: Fri, 6 May 2016 08:55:12 -0700
-Subject: [PATCH] fq_codel: add memory limitation per queue
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-On small embedded routers, one wants to control maximal amount of
-memory used by fq_codel, instead of controlling number of packets or
-bytes, since GRO/TSO make these not practical.
-
-Assuming skb->truesize is accurate, we have to keep track of
-skb->truesize sum for skbs in queue.
-
-This patch adds a new TCA_FQ_CODEL_MEMORY_LIMIT attribute.
-
-I chose a default value of 32 MBytes, which looks reasonable even
-for heavy duty usages. (Prior fq_codel users should not be hurt
-when they upgrade their kernels)
-
-Two fields are added to tc_fq_codel_qd_stats to report :
- - Current memory usage
- - Number of drops caused by memory limits
-
-# tc qd replace dev eth1 root est 1sec 4sec fq_codel memory_limit 4M
-..
-# tc -s -d qd sh dev eth1
-qdisc fq_codel 8008: root refcnt 257 limit 10240p flows 1024
- quantum 1514 target 5.0ms interval 100.0ms memory_limit 4Mb ecn
- Sent 2083566791363 bytes 1376214889 pkt (dropped 4994406, overlimits 0
-requeues 21705223)
- rate 9841Mbit 812549pps backlog 3906120b 376p requeues 21705223
- maxpacket 68130 drop_overlimit 4994406 new_flow_count 28855414
- ecn_mark 0 memory_used 4190048 drop_overmemory 4994406
- new_flows_len 1 old_flows_len 177
-
-Signed-off-by: Eric Dumazet <edumazet@google.com>
-Cc: Jesper Dangaard Brouer <brouer@redhat.com>
-Cc: Dave Täht <dave.taht@gmail.com>
-Cc: Sebastian Möller <moeller0@gmx.de>
-Signed-off-by: David S. Miller <davem@davemloft.net>
----
-
---- a/include/uapi/linux/pkt_sched.h
-+++ b/include/uapi/linux/pkt_sched.h
-@@ -712,6 +712,7 @@ enum {
- TCA_FQ_CODEL_QUANTUM,
- TCA_FQ_CODEL_CE_THRESHOLD,
- TCA_FQ_CODEL_DROP_BATCH_SIZE,
-+ TCA_FQ_CODEL_MEMORY_LIMIT,
- __TCA_FQ_CODEL_MAX
- };
-
-@@ -736,6 +737,8 @@ struct tc_fq_codel_qd_stats {
- __u32 new_flows_len; /* count of flows in new list */
- __u32 old_flows_len; /* count of flows in old list */
- __u32 ce_mark; /* packets above ce_threshold */
-+ __u32 memory_usage; /* in bytes */
-+ __u32 drop_overmemory;
- };
-
- struct tc_fq_codel_cl_stats {
---- a/net/sched/sch_fq_codel.c
-+++ b/net/sched/sch_fq_codel.c
-@@ -58,8 +58,11 @@ struct fq_codel_sched_data {
- u32 perturbation; /* hash perturbation */
- u32 quantum; /* psched_mtu(qdisc_dev(sch)); */
- u32 drop_batch_size;
-+ u32 memory_limit;
- struct codel_params cparams;
- struct codel_stats cstats;
-+ u32 memory_usage;
-+ u32 drop_overmemory;
- u32 drop_overlimit;
- u32 new_flow_count;
-
-@@ -141,6 +144,7 @@ static unsigned int fq_codel_drop(struct
- unsigned int maxbacklog = 0, idx = 0, i, len;
- struct fq_codel_flow *flow;
- unsigned int threshold;
-+ unsigned int mem = 0;
-
- /* Queue is full! Find the fat flow and drop packet(s) from it.
- * This might sound expensive, but with 1024 flows, we scan
-@@ -165,11 +169,13 @@ static unsigned int fq_codel_drop(struct
- do {
- skb = dequeue_head(flow);
- len += qdisc_pkt_len(skb);
-+ mem += skb->truesize;
- kfree_skb(skb);
- } while (++i < max_packets && len < threshold);
-
- flow->dropped += i;
- q->backlogs[idx] -= len;
-+ q->memory_usage -= mem;
- sch->qstats.drops += i;
- sch->qstats.backlog -= len;
- sch->q.qlen -= i;
-@@ -191,6 +197,7 @@ static int fq_codel_enqueue(struct sk_bu
- unsigned int idx, prev_backlog, prev_qlen;
- struct fq_codel_flow *flow;
- int uninitialized_var(ret);
-+ bool memory_limited;
-
- idx = fq_codel_classify(skb, sch, &ret);
- if (idx == 0) {
-@@ -213,7 +220,9 @@ static int fq_codel_enqueue(struct sk_bu
- flow->deficit = q->quantum;
- flow->dropped = 0;
- }
-- if (++sch->q.qlen <= sch->limit)
-+ q->memory_usage += skb->truesize;
-+ memory_limited = q->memory_usage > q->memory_limit;
-+ if (++sch->q.qlen <= sch->limit && !memory_limited)
- return NET_XMIT_SUCCESS;
-
- prev_backlog = sch->qstats.backlog;
-@@ -227,7 +236,8 @@ static int fq_codel_enqueue(struct sk_bu
- ret = fq_codel_drop(sch, q->drop_batch_size);
-
- q->drop_overlimit += prev_qlen - sch->q.qlen;
--
-+ if (memory_limited)
-+ q->drop_overmemory += prev_qlen - sch->q.qlen;
- /* As we dropped packet(s), better let upper stack know this */
- qdisc_tree_reduce_backlog(sch, prev_qlen - sch->q.qlen,
- prev_backlog - sch->qstats.backlog);
-@@ -296,6 +306,7 @@ begin:
- list_del_init(&flow->flowchain);
- goto begin;
- }
-+ q->memory_usage -= skb->truesize;
- qdisc_bstats_update(sch, skb);
- flow->deficit -= qdisc_pkt_len(skb);
- /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
-@@ -343,6 +354,7 @@ static const struct nla_policy fq_codel_
- [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 },
- [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 },
- [TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 },
-+ [TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 },
- };
-
- static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
-@@ -397,7 +409,11 @@ static int fq_codel_change(struct Qdisc
- if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])
- q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]));
-
-- while (sch->q.qlen > sch->limit) {
-+ if (tb[TCA_FQ_CODEL_MEMORY_LIMIT])
-+ q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT]));
-+
-+ while (sch->q.qlen > sch->limit ||
-+ q->memory_usage > q->memory_limit) {
- struct sk_buff *skb = fq_codel_dequeue(sch);
-
- q->cstats.drop_len += qdisc_pkt_len(skb);
-@@ -442,6 +458,7 @@ static int fq_codel_init(struct Qdisc *s
-
- sch->limit = 10*1024;
- q->flows_cnt = 1024;
-+ q->memory_limit = 32 << 20; /* 32 MBytes */
- q->drop_batch_size = 64;
- q->quantum = psched_mtu(qdisc_dev(sch));
- q->perturbation = prandom_u32();
-@@ -502,6 +519,8 @@ static int fq_codel_dump(struct Qdisc *s
- q->quantum) ||
- nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE,
- q->drop_batch_size) ||
-+ nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT,
-+ q->memory_limit) ||
- nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
- q->flows_cnt))
- goto nla_put_failure;
-@@ -530,6 +549,8 @@ static int fq_codel_dump_stats(struct Qd
- st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
- st.qdisc_stats.new_flow_count = q->new_flow_count;
- st.qdisc_stats.ce_mark = q->cstats.ce_mark;
-+ st.qdisc_stats.memory_usage = q->memory_usage;
-+ st.qdisc_stats.drop_overmemory = q->drop_overmemory;
-
- list_for_each(pos, &q->new_flows)
- st.qdisc_stats.new_flows_len++;
projects / openwrt / openwrt.git / blobdiff