Provide a sample kernel module that uses the pluggable multistream
scheduling framework. This module implements strict priority queue.
Signed-off-by: Yaogong Wang <ywang15@xxxxxxxx>
---
net/sctp/Kconfig | 12 ++++++
net/sctp/Makefile | 1 +
net/sctp/sctp_prio.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 116 insertions(+), 0 deletions(-)
create mode 100644 net/sctp/sctp_prio.c
diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
index 126b014..85c8ded 100644
--- a/net/sctp/Kconfig
+++ b/net/sctp/Kconfig
@@ -37,6 +37,18 @@ menuconfig IP_SCTP
if IP_SCTP
+config SCTP_SCHED_PRIO
+ tristate "SCTP Multistream Scheduling: Priority Queue"
+ default m
+ help
+ This module provides the ability to use priority queue
+ to schedule multiple streams within an association.
+
+ To compile this code as a module, choose M here: the
+ module will be called sctp_prio.
+
+ 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 4e8b65d..89be03a 100644
--- a/net/sctp/Makefile
+++ b/net/sctp/Makefile
@@ -4,6 +4,7 @@
obj-$(CONFIG_IP_SCTP) += sctp.o
obj-$(CONFIG_NET_SCTPPROBE) += sctp_probe.o
+obj-$(CONFIG_SCTP_SCHED_PRIO) += sctp_prio.o
sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \
protocol.o endpointola.o associola.o \
diff --git a/net/sctp/sctp_prio.c b/net/sctp/sctp_prio.c
new file mode 100644
index 0000000..11e7e11
--- /dev/null
+++ b/net/sctp/sctp_prio.c
@@ -0,0 +1,103 @@
+/*
+ * SCTP multistream scheduling: priority queue
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <net/sctp/sctp.h>
+
+static int prio_init(struct sctp_outq *q, gfp_t gfp)
+{
+ __u16 i;
+ 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]);
+
+ return 0;
+}
+
+static void prio_release(struct sctp_outq *q)
+{
+ kfree(q->out_chunk_list);
+ return;
+}
+
+static void prio_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 prio_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 *prio_dequeue_data(struct sctp_outq *q)
+{
+ struct sctp_chunk *ch = NULL;
+ __u16 prio = 0, i, cur = 0, *config = q->sched_config;
+ int flag = 0;
+
+ for (i = 0; i < q->asoc->c.sinit_num_ostreams; i++) {
+ if (!list_empty(&q->out_chunk_list[i]) &&
+ (flag == 0 || config[i] < prio)) {
+ cur = i;
+ flag = 1;
+ prio = config[i];
+ }
+ }
+
+ 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 prio_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_prio = {
+ .name = "prio",
+ .owner = THIS_MODULE,
+ .init = prio_init,
+ .release = prio_release,
+ .enqueue_head_data = prio_enqueue_head_data,
+ .enqueue_tail_data = prio_enqueue_tail_data,
+ .dequeue_data = prio_dequeue_data,
+ .is_empty = prio_is_empty,
+};
+
+static int __init sctp_prio_register(void)
+{
+ return sctp_register_sched(&sctp_prio);
+}
+
+static void __exit sctp_prio_unregister(void)
+{
+ sctp_unregister_sched(&sctp_prio);
+}
+
+module_init(sctp_prio_register);
+module_exit(sctp_prio_unregister);
+
+MODULE_AUTHOR("Yaogong Wang");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SCTP Multistream Scheduling: Priority Queue");
--
1.7.0.4
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