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| author | Xin Long <lucien.xin@gmail.com> | 2023-03-07 16:23:26 -0500 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2023-03-09 11:31:44 +0100 |
| commit | 4821a076eb602a6238528e9ebafeac853c833415 (patch) | |
| tree | e64fc7c9da205d33ca94f32cc82b72d49a85aa1e /include | |
| parent | 46ca833c060cff588a5fc2c25a1def8a1b6284e2 (diff) | |
sctp: add fair capacity stream scheduler
As it says in rfc8260#section-3.5 about the fair capacity scheduler:
A fair capacity distribution between the streams is used. This
scheduler considers the lengths of the messages of each stream and
schedules them in a specific way to maintain an equal capacity for
all streams. The details are implementation dependent. interleaving
user messages allows for a better realization of the fair capacity
usage.
This patch adds Fair Capacity Scheduler based on the foundations added
by commit 5bbbbe32a431 ("sctp: introduce stream scheduler foundations"):
A fc_list and a fc_length are added into struct sctp_stream_out_ext and
a fc_list is added into struct sctp_stream. In .enqueue, when there are
chunks enqueued into a stream, this stream will be linked into stream->
fc_list by its fc_list ordered by its fc_length. In .dequeue, it always
picks up the 1st skb from stream->fc_list. In .dequeue_done, fc_length
is increased by chunk's len and update its location in stream->fc_list
according to the its new fc_length.
Note that when the new fc_length overflows in .dequeue_done, instead of
resetting all fc_lengths to 0, we only reduced them by U32_MAX / 4 to
avoid a moment of imbalance in the scheduling, as Marcelo suggested.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/sctp/stream_sched.h | 1 | ||||
| -rw-r--r-- | include/net/sctp/structs.h | 7 | ||||
| -rw-r--r-- | include/uapi/linux/sctp.h | 3 |
3 files changed, 10 insertions, 1 deletions
diff --git a/include/net/sctp/stream_sched.h b/include/net/sctp/stream_sched.h index fa00dc20a0d7..913170710adb 100644 --- a/include/net/sctp/stream_sched.h +++ b/include/net/sctp/stream_sched.h @@ -58,5 +58,6 @@ void sctp_sched_ops_register(enum sctp_sched_type sched, struct sctp_sched_ops *sched_ops); void sctp_sched_ops_prio_init(void); void sctp_sched_ops_rr_init(void); +void sctp_sched_ops_fc_init(void); #endif /* __sctp_stream_sched_h__ */ diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index e1f6e7fc2b11..2f1c9f50b352 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -1429,6 +1429,10 @@ struct sctp_stream_out_ext { struct { struct list_head rr_list; }; + struct { + struct list_head fc_list; + __u32 fc_length; + }; }; }; @@ -1475,6 +1479,9 @@ struct sctp_stream { /* The next stream in line */ struct sctp_stream_out_ext *rr_next; }; + struct { + struct list_head fc_list; + }; }; struct sctp_stream_interleave *si; }; diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h index ed7d4ecbf53d..6814c5a1c4bc 100644 --- a/include/uapi/linux/sctp.h +++ b/include/uapi/linux/sctp.h @@ -1211,7 +1211,8 @@ enum sctp_sched_type { SCTP_SS_DEFAULT = SCTP_SS_FCFS, SCTP_SS_PRIO, SCTP_SS_RR, - SCTP_SS_MAX = SCTP_SS_RR + SCTP_SS_FC, + SCTP_SS_MAX = SCTP_SS_FC }; /* Probe Interval socket option */ |