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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-21 10:03:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-21 10:03:46 -0700
commitcb62ab71fe2b16e8203a0f0a2ef4eda23d761338 (patch)
tree536ba39658e47d511a489c52f7aac60cd78967e5 /net/sched/sch_fq_codel.c
parent31ed8e6f93a27304c9e157dab0267772cd94eaad (diff)
parent74863948f925d9f3bb4e3d3a783e49e9c662d839 (diff)
downloadlinux-cb62ab71fe2b16e8203a0f0a2ef4eda23d761338.tar.bz2
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking changes from David Miller: 1) Get rid of the error prone NLA_PUT*() macros that used an embedded goto. 2) Kill off the token-ring and MCA networking drivers, from Paul Gortmaker. 3) Reduce high-order allocations made by datagram AF_UNIX sockets, from Eric Dumazet. 4) Add PTP hardware clock support to IGB and IXGBE, from Richard Cochran and Jacob Keller. 5) Allow users to query timestamping capabilities of a card via ethtool, from Richard Cochran. 6) Add loadbalance mode to the teaming driver, from Jiri Pirko. Part of this is that we can now have BPF filters not attached to sockets, and the loadbalancing function is calculated using one. 7) Francois Romieu went through the network drivers removing gratuitous uses of netdev->base_addr, perhaps some day we can remove it completely but it's used for ISA probing still. 8) Add a BPF JIT for sparc. I know, who cares, right? :-) 9) Move networking sysctl registry away from using the compatability mode interfaces in the sysctl code. From Eric W Biederman. 10) Pavel Emelyanov added a way to save and restore TCP socket state via TCP_REPAIR, TCP_REPAIR_QUEUE, and TCP_QUEUE_SEQ socket options as well as a way to forcefully bind a socket to a port via the sk->sk_reuse value SK_FORCE_REUSE. There is also a TCP_REPAIR_OPTIONS which allows to reinstante the TCP options enabled on the connection. 11) Several enhancements from Eric Dumazet that, in particular, can enhance splice performance on TCP sockets significantly. a) Reset the offset of the per-socket sendmsg page when we know we're the only use of the page in linear_to_page(). b) Add facilities such that skb->data can be backed a page rather than SLAB kmalloc'd memory. In particular devices which were receiving into linear RX buffers can now end up providing paged data. The big result is that code like splice and GRO do not have to copy any more. 12) Allow a pure sender to more gracefully handle ACK backlogs in TCP. What can happen at high rates is that the sender hasn't grown his receive buffer limits at all (he's not receiving data so really doesn't need to), but the non-data ACKs consume receive buffer space. sk_add_backlog() is too aggressive in dropping frames in this case, so relax it's requirements by using the receive buffer plus the send buffer limit as the backlog limit instead of just the former. Also from Eric Dumazet. 13) Add ipv6 support to L2TP, from Benjamin LaHaise, James Chapman, and Chris Elston. 14) Implement TCP early retransmit (RFC 5827), from Yuchung Cheng. Basically, we can start fast retransmit before hiting the dupack threshold under certain conditions. 15) New CODEL active queue management packet scheduler, from Eric Dumazet based upon initial work by Dave Taht. Basically, the big feature is that packets are dropped (or ECN bits are set) based upon how long packets live in the queue, rather than the queue length (which is what RED uses). * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1341 commits) drivers/net/stmmac: seq_file fix memory leak ipv6/exthdrs: strict Pad1 and PadN check USB: qmi_wwan: Add ZTE (Vodafone) K3520-Z USB: qmi_wwan: Add ZTE (Vodafone) K3765-Z USB: qmi_wwan: Make forced int 4 whitelist generic net/ipv4: replace simple_strtoul with kstrtoul net/ipv4/ipconfig: neaten __setup placement net: qmi_wwan: Add Vodafone/Huawei K5005 support net: cdc_ether: Add ZTE WWAN matches before generic Ethernet ipv6: use skb coalescing in reassembly ipv4: use skb coalescing in defragmentation net: introduce skb_try_coalesce() net:ipv6:fixed space issues relating to operators. net:ipv6:fixed a trailing white space issue. ipv6: disable GSO on sockets hitting dst_allfrag tg3: use netdev_alloc_frag() API net: napi_frags_skb() is static ppp: avoid false drop_monitor false positives ipv6: bool/const conversions phase2 ipx: Remove spurious NULL checking in ipx_ioctl(). ...
Diffstat (limited to 'net/sched/sch_fq_codel.c')
-rw-r--r--net/sched/sch_fq_codel.c626
1 files changed, 626 insertions, 0 deletions
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
new file mode 100644
index 000000000000..9fc1c62ec80e
--- /dev/null
+++ b/net/sched/sch_fq_codel.c
@@ -0,0 +1,626 @@
+/*
+ * Fair Queue CoDel discipline
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Copyright (C) 2012 Eric Dumazet <edumazet@google.com>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/string.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/jhash.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/flow_keys.h>
+#include <net/codel.h>
+
+/* Fair Queue CoDel.
+ *
+ * Principles :
+ * Packets are classified (internal classifier or external) on flows.
+ * This is a Stochastic model (as we use a hash, several flows
+ * might be hashed on same slot)
+ * Each flow has a CoDel managed queue.
+ * Flows are linked onto two (Round Robin) lists,
+ * so that new flows have priority on old ones.
+ *
+ * For a given flow, packets are not reordered (CoDel uses a FIFO)
+ * head drops only.
+ * ECN capability is on by default.
+ * Low memory footprint (64 bytes per flow)
+ */
+
+struct fq_codel_flow {
+ struct sk_buff *head;
+ struct sk_buff *tail;
+ struct list_head flowchain;
+ int deficit;
+ u32 dropped; /* number of drops (or ECN marks) on this flow */
+ struct codel_vars cvars;
+}; /* please try to keep this structure <= 64 bytes */
+
+struct fq_codel_sched_data {
+ struct tcf_proto *filter_list; /* optional external classifier */
+ struct fq_codel_flow *flows; /* Flows table [flows_cnt] */
+ u32 *backlogs; /* backlog table [flows_cnt] */
+ u32 flows_cnt; /* number of flows */
+ u32 perturbation; /* hash perturbation */
+ u32 quantum; /* psched_mtu(qdisc_dev(sch)); */
+ struct codel_params cparams;
+ struct codel_stats cstats;
+ u32 drop_overlimit;
+ u32 new_flow_count;
+
+ struct list_head new_flows; /* list of new flows */
+ struct list_head old_flows; /* list of old flows */
+};
+
+static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q,
+ const struct sk_buff *skb)
+{
+ struct flow_keys keys;
+ unsigned int hash;
+
+ skb_flow_dissect(skb, &keys);
+ hash = jhash_3words((__force u32)keys.dst,
+ (__force u32)keys.src ^ keys.ip_proto,
+ (__force u32)keys.ports, q->perturbation);
+ return ((u64)hash * q->flows_cnt) >> 32;
+}
+
+static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch,
+ int *qerr)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ struct tcf_result res;
+ int result;
+
+ if (TC_H_MAJ(skb->priority) == sch->handle &&
+ TC_H_MIN(skb->priority) > 0 &&
+ TC_H_MIN(skb->priority) <= q->flows_cnt)
+ return TC_H_MIN(skb->priority);
+
+ if (!q->filter_list)
+ return fq_codel_hash(q, skb) + 1;
+
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+ result = tc_classify(skb, q->filter_list, &res);
+ if (result >= 0) {
+#ifdef CONFIG_NET_CLS_ACT
+ switch (result) {
+ case TC_ACT_STOLEN:
+ case TC_ACT_QUEUED:
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+ case TC_ACT_SHOT:
+ return 0;
+ }
+#endif
+ if (TC_H_MIN(res.classid) <= q->flows_cnt)
+ return TC_H_MIN(res.classid);
+ }
+ return 0;
+}
+
+/* helper functions : might be changed when/if skb use a standard list_head */
+
+/* remove one skb from head of slot queue */
+static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow)
+{
+ struct sk_buff *skb = flow->head;
+
+ flow->head = skb->next;
+ skb->next = NULL;
+ return skb;
+}
+
+/* add skb to flow queue (tail add) */
+static inline void flow_queue_add(struct fq_codel_flow *flow,
+ struct sk_buff *skb)
+{
+ if (flow->head == NULL)
+ flow->head = skb;
+ else
+ flow->tail->next = skb;
+ flow->tail = skb;
+ skb->next = NULL;
+}
+
+static unsigned int fq_codel_drop(struct Qdisc *sch)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ struct sk_buff *skb;
+ unsigned int maxbacklog = 0, idx = 0, i, len;
+ struct fq_codel_flow *flow;
+
+ /* Queue is full! Find the fat flow and drop packet from it.
+ * This might sound expensive, but with 1024 flows, we scan
+ * 4KB of memory, and we dont need to handle a complex tree
+ * in fast path (packet queue/enqueue) with many cache misses.
+ */
+ for (i = 0; i < q->flows_cnt; i++) {
+ if (q->backlogs[i] > maxbacklog) {
+ maxbacklog = q->backlogs[i];
+ idx = i;
+ }
+ }
+ flow = &q->flows[idx];
+ skb = dequeue_head(flow);
+ len = qdisc_pkt_len(skb);
+ q->backlogs[idx] -= len;
+ kfree_skb(skb);
+ sch->q.qlen--;
+ sch->qstats.drops++;
+ sch->qstats.backlog -= len;
+ flow->dropped++;
+ return idx;
+}
+
+static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ unsigned int idx;
+ struct fq_codel_flow *flow;
+ int uninitialized_var(ret);
+
+ idx = fq_codel_classify(skb, sch, &ret);
+ if (idx == 0) {
+ if (ret & __NET_XMIT_BYPASS)
+ sch->qstats.drops++;
+ kfree_skb(skb);
+ return ret;
+ }
+ idx--;
+
+ codel_set_enqueue_time(skb);
+ flow = &q->flows[idx];
+ flow_queue_add(flow, skb);
+ q->backlogs[idx] += qdisc_pkt_len(skb);
+ sch->qstats.backlog += qdisc_pkt_len(skb);
+
+ if (list_empty(&flow->flowchain)) {
+ list_add_tail(&flow->flowchain, &q->new_flows);
+ codel_vars_init(&flow->cvars);
+ q->new_flow_count++;
+ flow->deficit = q->quantum;
+ flow->dropped = 0;
+ }
+ if (++sch->q.qlen < sch->limit)
+ return NET_XMIT_SUCCESS;
+
+ q->drop_overlimit++;
+ /* Return Congestion Notification only if we dropped a packet
+ * from this flow.
+ */
+ if (fq_codel_drop(sch) == idx)
+ return NET_XMIT_CN;
+
+ /* As we dropped a packet, better let upper stack know this */
+ qdisc_tree_decrease_qlen(sch, 1);
+ return NET_XMIT_SUCCESS;
+}
+
+/* This is the specific function called from codel_dequeue()
+ * to dequeue a packet from queue. Note: backlog is handled in
+ * codel, we dont need to reduce it here.
+ */
+static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ struct fq_codel_flow *flow;
+ struct sk_buff *skb = NULL;
+
+ flow = container_of(vars, struct fq_codel_flow, cvars);
+ if (flow->head) {
+ skb = dequeue_head(flow);
+ q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb);
+ sch->q.qlen--;
+ }
+ return skb;
+}
+
+static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ struct sk_buff *skb;
+ struct fq_codel_flow *flow;
+ struct list_head *head;
+ u32 prev_drop_count, prev_ecn_mark;
+
+begin:
+ head = &q->new_flows;
+ if (list_empty(head)) {
+ head = &q->old_flows;
+ if (list_empty(head))
+ return NULL;
+ }
+ flow = list_first_entry(head, struct fq_codel_flow, flowchain);
+
+ if (flow->deficit <= 0) {
+ flow->deficit += q->quantum;
+ list_move_tail(&flow->flowchain, &q->old_flows);
+ goto begin;
+ }
+
+ prev_drop_count = q->cstats.drop_count;
+ prev_ecn_mark = q->cstats.ecn_mark;
+
+ skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats,
+ dequeue);
+
+ flow->dropped += q->cstats.drop_count - prev_drop_count;
+ flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
+
+ if (!skb) {
+ /* force a pass through old_flows to prevent starvation */
+ if ((head == &q->new_flows) && !list_empty(&q->old_flows))
+ list_move_tail(&flow->flowchain, &q->old_flows);
+ else
+ list_del_init(&flow->flowchain);
+ goto begin;
+ }
+ qdisc_bstats_update(sch, skb);
+ flow->deficit -= qdisc_pkt_len(skb);
+ /* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
+ * or HTB crashes. Defer it for next round.
+ */
+ if (q->cstats.drop_count && sch->q.qlen) {
+ qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
+ q->cstats.drop_count = 0;
+ }
+ return skb;
+}
+
+static void fq_codel_reset(struct Qdisc *sch)
+{
+ struct sk_buff *skb;
+
+ while ((skb = fq_codel_dequeue(sch)) != NULL)
+ kfree_skb(skb);
+}
+
+static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = {
+ [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 },
+ [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 },
+ [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 },
+ [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 },
+ [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 },
+ [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 },
+};
+
+static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ struct nlattr *tb[TCA_FQ_CODEL_MAX + 1];
+ int err;
+
+ if (!opt)
+ return -EINVAL;
+
+ err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy);
+ if (err < 0)
+ return err;
+ if (tb[TCA_FQ_CODEL_FLOWS]) {
+ if (q->flows)
+ return -EINVAL;
+ q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]);
+ if (!q->flows_cnt ||
+ q->flows_cnt > 65536)
+ return -EINVAL;
+ }
+ sch_tree_lock(sch);
+
+ if (tb[TCA_FQ_CODEL_TARGET]) {
+ u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]);
+
+ q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT;
+ }
+
+ if (tb[TCA_FQ_CODEL_INTERVAL]) {
+ u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]);
+
+ q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT;
+ }
+
+ if (tb[TCA_FQ_CODEL_LIMIT])
+ sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]);
+
+ if (tb[TCA_FQ_CODEL_ECN])
+ q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]);
+
+ if (tb[TCA_FQ_CODEL_QUANTUM])
+ q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM]));
+
+ while (sch->q.qlen > sch->limit) {
+ struct sk_buff *skb = fq_codel_dequeue(sch);
+
+ kfree_skb(skb);
+ q->cstats.drop_count++;
+ }
+ qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
+ q->cstats.drop_count = 0;
+
+ sch_tree_unlock(sch);
+ return 0;
+}
+
+static void *fq_codel_zalloc(size_t sz)
+{
+ void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
+
+ if (!ptr)
+ ptr = vzalloc(sz);
+ return ptr;
+}
+
+static void fq_codel_free(void *addr)
+{
+ if (addr) {
+ if (is_vmalloc_addr(addr))
+ vfree(addr);
+ else
+ kfree(addr);
+ }
+}
+
+static void fq_codel_destroy(struct Qdisc *sch)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+
+ tcf_destroy_chain(&q->filter_list);
+ fq_codel_free(q->backlogs);
+ fq_codel_free(q->flows);
+}
+
+static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ int i;
+
+ sch->limit = 10*1024;
+ q->flows_cnt = 1024;
+ q->quantum = psched_mtu(qdisc_dev(sch));
+ q->perturbation = net_random();
+ INIT_LIST_HEAD(&q->new_flows);
+ INIT_LIST_HEAD(&q->old_flows);
+ codel_params_init(&q->cparams);
+ codel_stats_init(&q->cstats);
+ q->cparams.ecn = true;
+
+ if (opt) {
+ int err = fq_codel_change(sch, opt);
+ if (err)
+ return err;
+ }
+
+ if (!q->flows) {
+ q->flows = fq_codel_zalloc(q->flows_cnt *
+ sizeof(struct fq_codel_flow));
+ if (!q->flows)
+ return -ENOMEM;
+ q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32));
+ if (!q->backlogs) {
+ fq_codel_free(q->flows);
+ return -ENOMEM;
+ }
+ for (i = 0; i < q->flows_cnt; i++) {
+ struct fq_codel_flow *flow = q->flows + i;
+
+ INIT_LIST_HEAD(&flow->flowchain);
+ }
+ }
+ if (sch->limit >= 1)
+ sch->flags |= TCQ_F_CAN_BYPASS;
+ else
+ sch->flags &= ~TCQ_F_CAN_BYPASS;
+ return 0;
+}
+
+static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ struct nlattr *opts;
+
+ opts = nla_nest_start(skb, TCA_OPTIONS);
+ if (opts == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET,
+ codel_time_to_us(q->cparams.target)) ||
+ nla_put_u32(skb, TCA_FQ_CODEL_LIMIT,
+ sch->limit) ||
+ nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL,
+ codel_time_to_us(q->cparams.interval)) ||
+ nla_put_u32(skb, TCA_FQ_CODEL_ECN,
+ q->cparams.ecn) ||
+ nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM,
+ q->quantum) ||
+ nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
+ q->flows_cnt))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, opts);
+ return skb->len;
+
+nla_put_failure:
+ return -1;
+}
+
+static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ struct tc_fq_codel_xstats st = {
+ .type = TCA_FQ_CODEL_XSTATS_QDISC,
+ };
+ struct list_head *pos;
+
+ st.qdisc_stats.maxpacket = q->cstats.maxpacket;
+ st.qdisc_stats.drop_overlimit = q->drop_overlimit;
+ st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
+ st.qdisc_stats.new_flow_count = q->new_flow_count;
+
+ list_for_each(pos, &q->new_flows)
+ st.qdisc_stats.new_flows_len++;
+
+ list_for_each(pos, &q->old_flows)
+ st.qdisc_stats.old_flows_len++;
+
+ return gnet_stats_copy_app(d, &st, sizeof(st));
+}
+
+static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg)
+{
+ return NULL;
+}
+
+static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid)
+{
+ return 0;
+}
+
+static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent,
+ u32 classid)
+{
+ /* we cannot bypass queue discipline anymore */
+ sch->flags &= ~TCQ_F_CAN_BYPASS;
+ return 0;
+}
+
+static void fq_codel_put(struct Qdisc *q, unsigned long cl)
+{
+}
+
+static struct tcf_proto **fq_codel_find_tcf(struct Qdisc *sch, unsigned long cl)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+
+ if (cl)
+ return NULL;
+ return &q->filter_list;
+}
+
+static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl,
+ struct sk_buff *skb, struct tcmsg *tcm)
+{
+ tcm->tcm_handle |= TC_H_MIN(cl);
+ return 0;
+}
+
+static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+ struct gnet_dump *d)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ u32 idx = cl - 1;
+ struct gnet_stats_queue qs = { 0 };
+ struct tc_fq_codel_xstats xstats;
+
+ if (idx < q->flows_cnt) {
+ const struct fq_codel_flow *flow = &q->flows[idx];
+ const struct sk_buff *skb = flow->head;
+
+ memset(&xstats, 0, sizeof(xstats));
+ xstats.type = TCA_FQ_CODEL_XSTATS_CLASS;
+ xstats.class_stats.deficit = flow->deficit;
+ xstats.class_stats.ldelay =
+ codel_time_to_us(flow->cvars.ldelay);
+ xstats.class_stats.count = flow->cvars.count;
+ xstats.class_stats.lastcount = flow->cvars.lastcount;
+ xstats.class_stats.dropping = flow->cvars.dropping;
+ if (flow->cvars.dropping) {
+ codel_tdiff_t delta = flow->cvars.drop_next -
+ codel_get_time();
+
+ xstats.class_stats.drop_next = (delta >= 0) ?
+ codel_time_to_us(delta) :
+ -codel_time_to_us(-delta);
+ }
+ while (skb) {
+ qs.qlen++;
+ skb = skb->next;
+ }
+ qs.backlog = q->backlogs[idx];
+ qs.drops = flow->dropped;
+ }
+ if (gnet_stats_copy_queue(d, &qs) < 0)
+ return -1;
+ if (idx < q->flows_cnt)
+ return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
+ return 0;
+}
+
+static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+ struct fq_codel_sched_data *q = qdisc_priv(sch);
+ unsigned int i;
+
+ if (arg->stop)
+ return;
+
+ for (i = 0; i < q->flows_cnt; i++) {
+ if (list_empty(&q->flows[i].flowchain) ||
+ arg->count < arg->skip) {
+ arg->count++;
+ continue;
+ }
+ if (arg->fn(sch, i + 1, arg) < 0) {
+ arg->stop = 1;
+ break;
+ }
+ arg->count++;
+ }
+}
+
+static const struct Qdisc_class_ops fq_codel_class_ops = {
+ .leaf = fq_codel_leaf,
+ .get = fq_codel_get,
+ .put = fq_codel_put,
+ .tcf_chain = fq_codel_find_tcf,
+ .bind_tcf = fq_codel_bind,
+ .unbind_tcf = fq_codel_put,
+ .dump = fq_codel_dump_class,
+ .dump_stats = fq_codel_dump_class_stats,
+ .walk = fq_codel_walk,
+};
+
+static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = {
+ .cl_ops = &fq_codel_class_ops,
+ .id = "fq_codel",
+ .priv_size = sizeof(struct fq_codel_sched_data),
+ .enqueue = fq_codel_enqueue,
+ .dequeue = fq_codel_dequeue,
+ .peek = qdisc_peek_dequeued,
+ .drop = fq_codel_drop,
+ .init = fq_codel_init,
+ .reset = fq_codel_reset,
+ .destroy = fq_codel_destroy,
+ .change = fq_codel_change,
+ .dump = fq_codel_dump,
+ .dump_stats = fq_codel_dump_stats,
+ .owner = THIS_MODULE,
+};
+
+static int __init fq_codel_module_init(void)
+{
+ return register_qdisc(&fq_codel_qdisc_ops);
+}
+
+static void __exit fq_codel_module_exit(void)
+{
+ unregister_qdisc(&fq_codel_qdisc_ops);
+}
+
+module_init(fq_codel_module_init)
+module_exit(fq_codel_module_exit)
+MODULE_AUTHOR("Eric Dumazet");
+MODULE_LICENSE("GPL");