Provide a sample kernel module that uses the pluggable multistream
scheduling framework. This modules implements weighted fair queue.
Signed-off-by: Yaogong Wang <ywang15@xxxxxxxx>
---
include/net/sctp/structs.h | 1 +
net/sctp/Kconfig | 12 ++++
net/sctp/Makefile | 1 +
net/sctp/outqueue.c | 1 +
net/sctp/sctp_wfq.c | 150 ++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 165 insertions(+), 0 deletions(-)
create mode 100644 net/sctp/sctp_wfq.c
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 1a76417..06be084 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1177,6 +1177,7 @@ struct sctp_outq {
const struct sctp_sched_ops *sched_ops;
__u16 sched_config_len;
void *sched_config;
+ void *sched_internal;
unsigned out_qlen; /* Total length of queued data chunks. */
diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
index 85c8ded..b2f9b47 100644
--- a/net/sctp/Kconfig
+++ b/net/sctp/Kconfig
@@ -49,6 +49,18 @@ config SCTP_SCHED_PRIO
If in doubt, say N.
+config SCTP_SCHED_WFQ
+ tristate "SCTP Multistream Scheduling: Weighted Fair Queue"
+ default m
+ help
+ This module provides the ability to use weighted fair queue
+ to schedule multiple streams within an association.
+
+ To compile this code as a module, choose M here: the
+ module will be called sctp_wfq.
+
+ If in doubt, say N.
+
config NET_SCTPPROBE
tristate "SCTP: Association probing"
depends on PROC_FS && KPROBES
diff --git a/net/sctp/Makefile b/net/sctp/Makefile
index 89be03a..f9b4068 100644
--- a/net/sctp/Makefile
+++ b/net/sctp/Makefile
@@ -5,6 +5,7 @@
obj-$(CONFIG_IP_SCTP) += sctp.o
obj-$(CONFIG_NET_SCTPPROBE) += sctp_probe.o
obj-$(CONFIG_SCTP_SCHED_PRIO) += sctp_prio.o
+obj-$(CONFIG_SCTP_SCHED_WFQ) += sctp_wfq.o
sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \
protocol.o endpointola.o associola.o \
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 1d3bd2e..1e3bc9b 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -180,6 +180,7 @@ int sctp_outq_init(struct sctp_association *asoc,
struct sctp_outq *q,
q->sched_ops = sctp_default_sched_ops;
q->sched_config_len = 0;
q->sched_config = NULL;
+ q->sched_internal = NULL;
err = q->sched_ops->init(q, gfp);
if (err)
return err;
diff --git a/net/sctp/sctp_wfq.c b/net/sctp/sctp_wfq.c
new file mode 100644
index 0000000..00edd2c
--- /dev/null
+++ b/net/sctp/sctp_wfq.c
@@ -0,0 +1,150 @@
+/*
+ * SCTP multistream scheduling: weighted fair queue
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <net/sctp/sctp.h>
+
+static int quantum = 1500;
+module_param(quantum, int, 0644);
+MODULE_PARM_DESC(quantum, "quantum in bytes");
+
+/*
+ * Weighted fair queue internal data structure
+ *
+ * implemented using deficit round robin technique
+ */
+struct wfq {
+ __u16 rr_ptr;
+ __u16 deficit[0];
+};
+
+static int wfq_init(struct sctp_outq *q, gfp_t gfp)
+{
+ __u16 i, *config = q->sched_config;
+ struct wfq *internal;
+
+ /* initiate out_chunk_list */
+ q->out_chunk_list = kmalloc(q->asoc->c.sinit_num_ostreams
+ * sizeof(struct list_head), gfp);
+ if (!q->out_chunk_list)
+ return -ENOMEM;
+ for (i = 0; i < q->asoc->c.sinit_num_ostreams; i++)
+ INIT_LIST_HEAD(&q->out_chunk_list[i]);
+
+ /* initiate internal data structure */
+ q->sched_internal = kmalloc((q->asoc->c.sinit_num_ostreams + 1) *
+ sizeof(__u16), gfp);
+ if (!q->sched_internal) {
+ kfree(q->out_chunk_list);
+ return -ENOMEM;
+ }
+ internal = (struct wfq *)q->sched_internal;
+ internal->rr_ptr = 0;
+ internal->deficit[0] = config[0] * quantum;
+ for (i = 1; i < q->asoc->c.sinit_num_ostreams; i++)
+ internal->deficit[i] = 0;
+
+ return 0;
+}
+
+static void wfq_release(struct sctp_outq *q)
+{
+ kfree(q->out_chunk_list);
+ kfree(q->sched_internal);
+ return;
+}
+
+static void wfq_enqueue_head_data(struct sctp_outq *q,
+ struct sctp_chunk *ch)
+{
+ list_add(&ch->list, &q->out_chunk_list[ch->sinfo.sinfo_stream]);
+ q->out_qlen += ch->skb->len;
+ return;
+}
+
+static void wfq_enqueue_tail_data(struct sctp_outq *q, struct sctp_chunk *ch)
+{
+ list_add_tail(&ch->list, &q->out_chunk_list[ch->sinfo.sinfo_stream]);
+ q->out_qlen += ch->skb->len;
+ return;
+}
+
+static struct sctp_chunk *wfq_dequeue_data(struct sctp_outq *q)
+{
+ struct sctp_chunk *ch = NULL;
+ struct wfq *internal = (struct wfq *)q->sched_internal;
+ __u16 i, cur = 0, *config = q->sched_config;
+ int flag = 0, hasdata = 0;
+
+ for (i = 0; i < q->asoc->c.sinit_num_ostreams || hasdata; i++) {
+ if (!list_empty(&q->out_chunk_list[internal->rr_ptr])) {
+ hasdata = 1;
+ struct list_head *tmp_entry =
+ q->out_chunk_list[internal->rr_ptr].next;
+ struct sctp_chunk *tmp_ch =
+ list_entry(tmp_entry, struct sctp_chunk, list);
+ if (tmp_ch->skb->len <=
+ internal->deficit[internal->rr_ptr]) {
+ internal->deficit[internal->rr_ptr] -=
+ tmp_ch->skb->len;
+ cur = internal->rr_ptr;
+ flag = 1;
+ break;
+ }
+ } else {
+ internal->deficit[internal->rr_ptr] = 0;
+ }
+ internal->rr_ptr = (internal->rr_ptr + 1) %
+ q->asoc->c.sinit_num_ostreams;
+ internal->deficit[internal->rr_ptr] +=
+ config[internal->rr_ptr] * quantum;
+ }
+
+ if (flag) {
+ struct list_head *entry = q->out_chunk_list[cur].next;
+ ch = list_entry(entry, struct sctp_chunk, list);
+ list_del_init(entry);
+ q->out_qlen -= ch->skb->len;
+ }
+ return ch;
+}
+
+static inline int wfq_is_empty(struct sctp_outq *q)
+{
+ __u16 i;
+ for (i = 0; i < q->asoc->c.sinit_num_ostreams; i++)
+ if (!list_empty(&q->out_chunk_list[i]))
+ return 0;
+ return 1;
+}
+
+static struct sctp_sched_ops sctp_wfq = {
+ .name = "wfq",
+ .owner = THIS_MODULE,
+ .init = wfq_init,
+ .release = wfq_release,
+ .enqueue_head_data = wfq_enqueue_head_data,
+ .enqueue_tail_data = wfq_enqueue_tail_data,
+ .dequeue_data = wfq_dequeue_data,
+ .is_empty = wfq_is_empty,
+};
+
+static int __init sctp_wfq_register(void)
+{
+ return sctp_register_sched(&sctp_wfq);
+}
+
+static void __exit sctp_wfq_unregister(void)
+{
+ sctp_unregister_sched(&sctp_wfq);
+}
+
+module_init(sctp_wfq_register);
+module_exit(sctp_wfq_unregister);
+
+MODULE_AUTHOR("Yaogong Wang");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SCTP Multistream Scheduling: Weighted Fair Queue");
--
1.7.0.4
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