Introduce SCTP Stream Schedulers

PATCH In review Marcelo Ricardo Leitner 2 participants 12 messages Oct 3, 2017

Subsystems (3)

Networking Network drivers SCTP protocol

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Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #0 lore raw

v2 cover Introduce SCTP Stream Schedulers

This patchset introduces the SCTP Stream Schedulers are defined by
https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13

It provides 3 schedulers at the moment: FCFS, Priority and Round Robin. The other 3, Round Robin per packet, Fair Capacity and Weighted Fair Capacity will be added later. More specifically, WFQ is required by WebRTC Datachannels.

The draft also defines the idata chunk, allowing a usermsg to be interrupted by another piece of idata from another stream. This patchset *doesn't* include it. It will be posted later by Xin Long. Its integration with this patchset is very simple and it basically only requires a tweak in sctp_sched_dequeue_done(), to ignore datamsg boundaries.

The first 5 patches are a preparation for the next ones. The most relevant patches are the 4th and 6th ones. More details are available on each patch.

v2: changelog update on patch 3

Marcelo Ricardo Leitner (10):
sctp: silence warns on sctp_stream_init allocations
sctp: factor out stream->out allocation
sctp: factor out stream->in allocation
sctp: introduce struct sctp_stream_out_ext
sctp: introduce sctp_chunk_stream_no
sctp: introduce stream scheduler foundations
sctp: add sockopt to get/set stream scheduler
sctp: add sockopt to get/set stream scheduler parameters
sctp: introduce priority based stream scheduler
sctp: introduce round robin stream scheduler

 include/net/sctp/stream_sched.h |  72 +++++++++
 include/net/sctp/structs.h      |  63 +++++++-
 include/uapi/linux/sctp.h       |  16 ++
 net/sctp/Makefile               |   3 +-
 net/sctp/chunk.c                |   6 +-
 net/sctp/outqueue.c             |  63 ++++----
 net/sctp/sm_sideeffect.c        |   3 +
 net/sctp/socket.c               | 179 ++++++++++++++++++++-
 net/sctp/stream.c               | 196 +++++++++++++++++++----
 net/sctp/stream_sched.c         | 275 +++++++++++++++++++++++++++++++
 net/sctp/stream_sched_prio.c    | 347 ++++++++++++++++++++++++++++++++++++++++
 net/sctp/stream_sched_rr.c      | 201 +++++++++++++++++++++++
 12 files changed, 1347 insertions(+), 77 deletions(-)
 create mode 100644 include/net/sctp/stream_sched.h
 create mode 100644 net/sctp/stream_sched.c
 create mode 100644 net/sctp/stream_sched_prio.c
 create mode 100644 net/sctp/stream_sched_rr.c

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #1 lore raw

PATCH v2 1/10 sctp: silence warns on sctp_stream_init allocations

As SCTP supports up to 65535 streams, that can lead to very large allocations in sctp_stream_init(). As Xin Long noticed, systems with small amounts of memory are more prone to not have enough memory and dump warnings on dmesg initiated by user actions. Thus, silence them.

Also, if the reallocation of stream->out is not necessary, skip it and keep the memory we already have.

Reported-by Xin Long <[email protected]>

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 net/sctp/stream.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

net/sctp/stream.c +7 -1

index 63ea1550371493ec8863627c7a43f46a22f4a4c9..1afa9555808390d5fc736727422d9700a3855613 100644
@@ -40,9 +40,14 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 {
 	int i;
 
+	gfp |= __GFP_NOWARN;
+
 	/* Initial stream->out size may be very big, so free it and alloc
-	 * a new one with new outcnt to save memory.
+	 * a new one with new outcnt to save memory if needed.
 	 */
+	if (outcnt = stream->outcnt)
+		goto in;
+
 	kfree(stream->out);
 
 	stream->out = kcalloc(outcnt, sizeof(*stream->out), gfp);

@@ -53,6 +58,7 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 	for (i = 0; i < stream->outcnt; i++)
 		stream->out[i].state = SCTP_STREAM_OPEN;
 
+in:
 	if (!incnt)
 		return 0;

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #2 lore raw

PATCH v2 2/10 sctp: factor out stream->out allocation

In reply to Marcelo Ricardo Leitner

There is 1 place allocating it and 2 other reallocating. Move such procedures to a common function.

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 net/sctp/stream.c | 52 ++++++++++++++++++++++++++++++++--------------------
 1 file changed, 32 insertions(+), 20 deletions(-)

net/sctp/stream.c +32 ~~-20~~

index 1afa9555808390d5fc736727422d9700a3855613..6d0e997d301f89e165367106c02e82f8a6c3a877 100644
@@ -35,6 +35,30 @@
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
 
+static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
+				 gfp_t gfp)
+{
+	struct sctp_stream_out *out;
+
+	out = kmalloc_array(outcnt, sizeof(*out), gfp);
+	if (!out)
+		return -ENOMEM;
+
+	if (stream->out) {
+		memcpy(out, stream->out, min(outcnt, stream->outcnt) *
+					 sizeof(*out));
+		kfree(stream->out);
+	}
+
+	if (outcnt > stream->outcnt)
+		memset(out + stream->outcnt, 0,
+		       (outcnt - stream->outcnt) * sizeof(*out));
+
+	stream->out = out;
+
+	return 0;
+}
+
 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 		     gfp_t gfp)
 {

@@ -48,11 +72,9 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 	if (outcnt = stream->outcnt)
 		goto in;
 
-	kfree(stream->out);
-
-	stream->out = kcalloc(outcnt, sizeof(*stream->out), gfp);
-	if (!stream->out)
-		return -ENOMEM;
+	i = sctp_stream_alloc_out(stream, outcnt, gfp);
+	if (i)
+		return i;
 
 	stream->outcnt = outcnt;
 	for (i = 0; i < stream->outcnt; i++)

@@ -276,15 +298,9 @@ int sctp_send_add_streams(struct sctp_association *asoc,
 	}
 
 	if (out) {
-		struct sctp_stream_out *streamout;
-
-		streamout = krealloc(stream->out, outcnt * sizeof(*streamout),
-				     GFP_KERNEL);
-		if (!streamout)
+		retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
+		if (retval)
 			goto out;
-
-		memset(streamout + stream->outcnt, 0, out * sizeof(*streamout));
-		stream->out = streamout;
 	}
 
 	chunk = sctp_make_strreset_addstrm(asoc, out, in);

@@ -682,10 +698,10 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in(
 	struct sctp_strreset_addstrm *addstrm = param.v;
 	struct sctp_stream *stream = &asoc->stream;
 	__u32 result = SCTP_STRRESET_DENIED;
-	struct sctp_stream_out *streamout;
 	struct sctp_chunk *chunk = NULL;
 	__u32 request_seq, outcnt;
 	__u16 out, i;
+	int ret;
 
 	request_seq = ntohl(addstrm->request_seq);
 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||

@@ -714,14 +730,10 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in(
 	if (!out || outcnt > SCTP_MAX_STREAM)
 		goto out;
 
-	streamout = krealloc(stream->out, outcnt * sizeof(*streamout),
-			     GFP_ATOMIC);
-	if (!streamout)
+	ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
+	if (ret)
 		goto out;
 
-	memset(streamout + stream->outcnt, 0, out * sizeof(*streamout));
-	stream->out = streamout;
-
 	chunk = sctp_make_strreset_addstrm(asoc, out, 0);
 	if (!chunk)
 		goto out;

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #3 lore raw

PATCH v2 3/10 sctp: factor out stream->in allocation

In reply to Marcelo Ricardo Leitner

There is 1 place allocating it and another reallocating. Move such procedures to a common function.

v2: updated changelog

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 net/sctp/stream.c | 36 ++++++++++++++++++++++++++++--------
 1 file changed, 28 insertions(+), 8 deletions(-)

net/sctp/stream.c +28 -8

index 6d0e997d301f89e165367106c02e82f8a6c3a877..952437d656cc71ad1c133a736c539eff9a8d80c2 100644
@@ -59,6 +59,31 @@ static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
 	return 0;
 }
 
+static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
+				gfp_t gfp)
+{
+	struct sctp_stream_in *in;
+
+	in = kmalloc_array(incnt, sizeof(*stream->in), gfp);
+
+	if (!in)
+		return -ENOMEM;
+
+	if (stream->in) {
+		memcpy(in, stream->in, min(incnt, stream->incnt) *
+				       sizeof(*in));
+		kfree(stream->in);
+	}
+
+	if (incnt > stream->incnt)
+		memset(in + stream->incnt, 0,
+		       (incnt - stream->incnt) * sizeof(*in));
+
+	stream->in = in;
+
+	return 0;
+}
+
 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 		     gfp_t gfp)
 {

@@ -84,8 +109,8 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 	if (!incnt)
 		return 0;
 
-	stream->in = kcalloc(incnt, sizeof(*stream->in), gfp);
-	if (!stream->in) {
+	i = sctp_stream_alloc_in(stream, incnt, gfp);
+	if (i) {
 		kfree(stream->out);
 		stream->out = NULL;
 		return -ENOMEM;

@@ -623,7 +648,6 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out(
 	struct sctp_strreset_addstrm *addstrm = param.v;
 	struct sctp_stream *stream = &asoc->stream;
 	__u32 result = SCTP_STRRESET_DENIED;
-	struct sctp_stream_in *streamin;
 	__u32 request_seq, incnt;
 	__u16 in, i;

@@ -670,13 +694,9 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out(
 	if (!in || incnt > SCTP_MAX_STREAM)
 		goto out;
 
-	streamin = krealloc(stream->in, incnt * sizeof(*streamin),
-			    GFP_ATOMIC);
-	if (!streamin)
+	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
 		goto out;
 
-	memset(streamin + stream->incnt, 0, in * sizeof(*streamin));
-	stream->in = streamin;
 	stream->incnt = incnt;
 
 	result = SCTP_STRRESET_PERFORMED;

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #4 lore raw

PATCH v2 4/10 sctp: introduce struct sctp_stream_out_ext

In reply to Marcelo Ricardo Leitner

With the stream schedulers, sctp_stream_out will become too big to be allocated by kmalloc and as we need to allocate with BH disabled, we cannot use __vmalloc in sctp_stream_init().

This patch moves out the stats from sctp_stream_out to sctp_stream_out_ext, which will be allocated only when the application tries to sendmsg something on it.

Just the introduction of sctp_stream_out_ext would already fix the issue described above by splitting the allocation in two. Moving the stats to it also reduces the pressure on the allocator as we will ask for less memory atomically when creating the socket and we will use GFP_KERNEL later.

Then, for stream schedulers, we will just use sctp_stream_out_ext.

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 include/net/sctp/structs.h | 10 ++++++++--
 net/sctp/chunk.c           |  6 +++---
 net/sctp/outqueue.c        |  4 ++--
 net/sctp/socket.c          | 27 +++++++++++++++++++++------
 net/sctp/stream.c          | 16 ++++++++++++++++
 5 files changed, 50 insertions(+), 13 deletions(-)

include/net/sctp/structs.h +8 -2

index 0477945de1a3cf5c27348e99d9a30e02c491d1de..9b2b30b3ba4dfd10c24c3e06ed80779180a06baf 100644
@@ -84,6 +84,7 @@ struct sctp_ulpq;
 struct sctp_ep_common;
 struct crypto_shash;
 struct sctp_stream;
+struct sctp_stream_out;
 
 
 #include <net/sctp/tsnmap.h>

@@ -380,6 +381,7 @@ struct sctp_sender_hb_info {
 
 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 		     gfp_t gfp);
+int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
 void sctp_stream_free(struct sctp_stream *stream);
 void sctp_stream_clear(struct sctp_stream *stream);
 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);

@@ -1315,11 +1317,15 @@ struct sctp_inithdr_host {
 	__u32 initial_tsn;
 };
 
+struct sctp_stream_out_ext {
+	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
+	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
+};
+
 struct sctp_stream_out {
 	__u16	ssn;
 	__u8	state;
-	__u64	abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
-	__u64	abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
+	struct sctp_stream_out_ext *ext;
 };
 
 struct sctp_stream_in {

net/sctp/chunk.c +3 -3

index 3afac275ee82dbec825dd71378dffe69a53718a7..7b261afc47b9d709fdd780a93aaba874f35d79be 100644
@@ -311,10 +311,10 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
 
 		if (chunk->sent_count) {
 			chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
-			streamout->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
+			streamout->ext->abandoned_sent[SCTP_PR_INDEX(TTL)]++;
 		} else {
 			chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
-			streamout->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
+			streamout->ext->abandoned_unsent[SCTP_PR_INDEX(TTL)]++;
 		}
 		return 1;
 	} else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) &&

@@ -323,7 +323,7 @@ int sctp_chunk_abandoned(struct sctp_chunk *chunk)
 			&chunk->asoc->stream.out[chunk->sinfo.sinfo_stream];
 
 		chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
-		streamout->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
+		streamout->ext->abandoned_sent[SCTP_PR_INDEX(RTX)]++;
 		return 1;
 	} else if (!SCTP_PR_POLICY(chunk->sinfo.sinfo_flags) &&
 		   chunk->msg->expires_at &&

net/sctp/outqueue.c +2 -2

index 2966ff400755fe93e3658e09d3bb44b9d7d19d2e..746b07b7937d8730824b9e09917d947aa7863ec6 100644
@@ -366,7 +366,7 @@ static int sctp_prsctp_prune_sent(struct sctp_association *asoc,
 		streamout = &asoc->stream.out[chk->sinfo.sinfo_stream];
 		asoc->sent_cnt_removable--;
 		asoc->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
-		streamout->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
+		streamout->ext->abandoned_sent[SCTP_PR_INDEX(PRIO)]++;
 
 		if (!chk->tsn_gap_acked) {
 			if (chk->transport)

@@ -404,7 +404,7 @@ static int sctp_prsctp_prune_unsent(struct sctp_association *asoc,
 			struct sctp_stream_out *streamout  				&asoc->stream.out[chk->sinfo.sinfo_stream];
 
-			streamout->abandoned_unsent[SCTP_PR_INDEX(PRIO)]++;
+			streamout->ext->abandoned_unsent[SCTP_PR_INDEX(PRIO)]++;
 		}
 
 		msg_len -= SCTP_DATA_SNDSIZE(chk) +

net/sctp/socket.c +21 -2

index d4730ada7f3233367be7a0e3bb10e286a25602c8..d207734326b085e60625e4333f74221481114892 100644
@@ -1927,6 +1927,13 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
 		goto out_free;
 	}
 
+	/* Allocate sctp_stream_out_ext if not already done */
+	if (unlikely(!asoc->stream.out[sinfo->sinfo_stream].ext)) {
+		err = sctp_stream_init_ext(&asoc->stream, sinfo->sinfo_stream);
+		if (err)
+			goto out_free;
+	}
+
 	if (sctp_wspace(asoc) < msg_len)
 		sctp_prsctp_prune(asoc, sinfo, msg_len - sctp_wspace(asoc));

@@ -6645,7 +6652,7 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
 					   char __user *optval,
 					   int __user *optlen)
 {
-	struct sctp_stream_out *streamout;
+	struct sctp_stream_out_ext *streamoute;
 	struct sctp_association *asoc;
 	struct sctp_prstatus params;
 	int retval = -EINVAL;

@@ -6668,21 +6675,29 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
 	if (!asoc || params.sprstat_sid >= asoc->stream.outcnt)
 		goto out;
 
-	streamout = &asoc->stream.out[params.sprstat_sid];
+	streamoute = asoc->stream.out[params.sprstat_sid].ext;
+	if (!streamoute) {
+		/* Not allocated yet, means all stats are 0 */
+		params.sprstat_abandoned_unsent = 0;
+		params.sprstat_abandoned_sent = 0;
+		retval = 0;
+		goto out;
+	}
+
 	if (policy = SCTP_PR_SCTP_NONE) {
 		params.sprstat_abandoned_unsent = 0;
 		params.sprstat_abandoned_sent = 0;
 		for (policy = 0; policy <= SCTP_PR_INDEX(MAX); policy++) {
 			params.sprstat_abandoned_unsent +-				streamout->abandoned_unsent[policy];
+				streamoute->abandoned_unsent[policy];
 			params.sprstat_abandoned_sent +-				streamout->abandoned_sent[policy];
+				streamoute->abandoned_sent[policy];
 		}
 	} else {
 		params.sprstat_abandoned_unsent -			streamout->abandoned_unsent[__SCTP_PR_INDEX(policy)];
+			streamoute->abandoned_unsent[__SCTP_PR_INDEX(policy)];
 		params.sprstat_abandoned_sent -			streamout->abandoned_sent[__SCTP_PR_INDEX(policy)];
+			streamoute->abandoned_sent[__SCTP_PR_INDEX(policy)];
 	}
 
 	if (put_user(len, optlen) || copy_to_user(optval, &params, len)) {

net/sctp/stream.c +16 -0

index 952437d656cc71ad1c133a736c539eff9a8d80c2..055ca25bbc91bf932db8048c72a1b11cc2214942 100644
@@ -121,8 +121,24 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 	return 0;
 }
 
+int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
+{
+	struct sctp_stream_out_ext *soute;
+
+	soute = kzalloc(sizeof(*soute), GFP_KERNEL);
+	if (!soute)
+		return -ENOMEM;
+	stream->out[sid].ext = soute;
+
+	return 0;
+}
+
 void sctp_stream_free(struct sctp_stream *stream)
 {
+	int i;
+
+	for (i = 0; i < stream->outcnt; i++)
+		kfree(stream->out[i].ext);
 	kfree(stream->out);
 	kfree(stream->in);
 }

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #5 lore raw

PATCH v2 5/10 sctp: introduce sctp_chunk_stream_no

In reply to Marcelo Ricardo Leitner

Add a helper to fetch the stream number from a given chunk.

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 include/net/sctp/structs.h | 5 +++++
 1 file changed, 5 insertions(+)

include/net/sctp/structs.h +5 -0

index 9b2b30b3ba4dfd10c24c3e06ed80779180a06baf..c48f7999fe9b80c5b5e41910a3608059b94140a7 100644
@@ -642,6 +642,11 @@ void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
 		     union sctp_addr *);
 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
 
+static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
+{
+	return ntohs(ch->subh.data_hdr->stream);
+}
+
 enum {
 	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
 	SCTP_ADDR_SRC,		/* address can be used as source */

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #6 lore raw

PATCH v2 6/10 sctp: introduce stream scheduler foundations

In reply to Marcelo Ricardo Leitner

This patch introduces the hooks necessary to do stream scheduling, as per RFC Draft ndata. It also introduces the first scheduler, which is what we do today but now factored out: first come first served (FCFS).

With stream scheduling now we have to track which chunk was enqueued on which stream and be able to select another other than the in front of the main outqueue. So we introduce a list on sctp_stream_out_ext structure for this purpose.

We reuse sctp_chunk->transmitted_list space for the list above, as the chunk cannot belong to the two lists at the same time. By using the union in there, we can have distinct names for these moments.

sctp_sched_ops are the operations expected to be implemented by each scheduler. The dequeueing is a bit particular to this implementation but it is to match how we dequeue packets today. We first dequeue and then check if it fits the packet and if not, we requeue it at head. Thus why we don't have a peek operation but have dequeue_done instead, which is called once the chunk can be safely considered as transmitted.

The check removed from sctp_outq_flush is now performed by sctp_stream_outq_migrate, which is only called during assoc setup. (sctp_sendmsg() also checks for it)

The only operation that is foreseen but not yet added here is a way to signalize that a new packet is starting or that the packet is done, for round robin scheduler per packet, but is intentionally left to the patch that actually implements it.

Support for I-DATA chunks, also described in this RFC, with user message interleaving is straightforward as it just requires the schedulers to probe for the feature and ignore datamsg boundaries when dequeueing.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 include/net/sctp/stream_sched.h |  72 +++++++++++
 include/net/sctp/structs.h      |  15 ++-
 include/uapi/linux/sctp.h       |   6 +
 net/sctp/Makefile               |   2 +-
 net/sctp/outqueue.c             |  59 +++++----
 net/sctp/sm_sideeffect.c        |   3 +
 net/sctp/stream.c               |  88 +++++++++++--
 net/sctp/stream_sched.c         | 270 ++++++++++++++++++++++++++++++++++++++++
 8 files changed, 477 insertions(+), 38 deletions(-)
 create mode 100644 include/net/sctp/stream_sched.h
 create mode 100644 net/sctp/stream_sched.c

include/net/sctp/stream_sched.h new file +72 -0

new file mode 100644
index 0000000000000000000000000000000000000000..c676550a4c7dd0ea27ac0e14437d0a2b451ef499
@@ -0,0 +1,72 @@
+/* SCTP kernel implementation
+ * (C) Copyright Red Hat Inc. 2017
+ *
+ * These are definitions used by the stream schedulers, defined in RFC
+ * draft ndata (https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-11)
+ *
+ * This SCTP implementation 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, or (at your option)
+ * any later version.
+ *
+ * This SCTP implementation  is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ *                 ************************
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU CC; see the file COPYING.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email addresses:
+ *    lksctp developers <[email protected]>
+ *
+ * Written or modified by:
+ *   Marcelo Ricardo Leitner <[email protected]>
+ */
+
+#ifndef __sctp_stream_sched_h__
+#define __sctp_stream_sched_h__
+
+struct sctp_sched_ops {
+	/* Property handling for a given stream */
+	int (*set)(struct sctp_stream *stream, __u16 sid, __u16 value,
+		   gfp_t gfp);
+	int (*get)(struct sctp_stream *stream, __u16 sid, __u16 *value);
+
+	/* Init the specific scheduler */
+	int (*init)(struct sctp_stream *stream);
+	/* Init a stream */
+	int (*init_sid)(struct sctp_stream *stream, __u16 sid, gfp_t gfp);
+	/* Frees the entire thing */
+	void (*free)(struct sctp_stream *stream);
+
+	/* Enqueue a chunk */
+	void (*enqueue)(struct sctp_outq *q, struct sctp_datamsg *msg);
+	/* Dequeue a chunk */
+	struct sctp_chunk *(*dequeue)(struct sctp_outq *q);
+	/* Called only if the chunk fit the packet */
+	void (*dequeue_done)(struct sctp_outq *q, struct sctp_chunk *chunk);
+	/* Sched all chunks already enqueued */
+	void (*sched_all)(struct sctp_stream *steam);
+	/* Unched all chunks already enqueued */
+	void (*unsched_all)(struct sctp_stream *steam);
+};
+
+int sctp_sched_set_sched(struct sctp_association *asoc,
+			 enum sctp_sched_type sched);
+int sctp_sched_get_sched(struct sctp_association *asoc);
+int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
+			 __u16 value, gfp_t gfp);
+int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
+			 __u16 *value);
+void sctp_sched_dequeue_done(struct sctp_outq *q, struct sctp_chunk *ch);
+
+void sctp_sched_dequeue_common(struct sctp_outq *q, struct sctp_chunk *ch);
+int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp);
+struct sctp_sched_ops *sctp_sched_ops_from_stream(struct sctp_stream *stream);
+
+#endif /* __sctp_stream_sched_h__ */

include/net/sctp/structs.h +12 -3

index c48f7999fe9b80c5b5e41910a3608059b94140a7..3c22a30fd71b4ef87419a77cf69b00807a5986bb 100644
@@ -84,7 +84,6 @@ struct sctp_ulpq;
 struct sctp_ep_common;
 struct crypto_shash;
 struct sctp_stream;
-struct sctp_stream_out;
 
 
 #include <net/sctp/tsnmap.h>

@@ -531,8 +530,12 @@ struct sctp_chunk {
 	/* How many times this chunk have been sent, for prsctp RTX policy */
 	int sent_count;
 
-	/* This is our link to the per-transport transmitted list.  */
-	struct list_head transmitted_list;
+	union {
+		/* This is our link to the per-transport transmitted list.  */
+		struct list_head transmitted_list;
+		/* List in specific stream outq */
+		struct list_head stream_list;
+	};
 
 	/* This field is used by chunks that hold fragmented data.
 	 * For the first fragment this is the list that holds the rest of

@@ -1019,6 +1022,9 @@ struct sctp_outq {
 	/* Data pending that has never been transmitted.  */
 	struct list_head out_chunk_list;
 
+	/* Stream scheduler being used */
+	struct sctp_sched_ops *sched;
+
 	unsigned int out_qlen;	/* Total length of queued data chunks. */
 
 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */

@@ -1325,6 +1331,7 @@ struct sctp_inithdr_host {
 struct sctp_stream_out_ext {
 	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
 	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
+	struct list_head outq; /* chunks enqueued by this stream */
 };
 
 struct sctp_stream_out {

@@ -1342,6 +1349,8 @@ struct sctp_stream {
 	struct sctp_stream_in *in;
 	__u16 outcnt;
 	__u16 incnt;
+	/* Current stream being sent, if any */
+	struct sctp_stream_out *out_curr;
 };
 
 #define SCTP_STREAM_CLOSED		0x00

include/uapi/linux/sctp.h +6 -0

index 6217ff8500a1d818fd1002fbd6f81c0c11974665..4487e7625ddbd48be1868a8292a807ecd0a314bc 100644
@@ -1088,4 +1088,10 @@ struct sctp_add_streams {
 	uint16_t sas_outstrms;
 };
 
+/* SCTP Stream schedulers */
+enum sctp_sched_type {
+	SCTP_SS_FCFS,
+	SCTP_SS_MAX = SCTP_SS_FCFS
+};
+
 #endif /* _UAPI_SCTP_H */

net/sctp/Makefile +1 -1

index 70f1b570bab9764d692f1c2e605d76d056cda2cd..0f6e6d1d69fd336b4a99f896851b0120f9a0d1e0 100644
@@ -12,7 +12,7 @@ sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \
 	  inqueue.o outqueue.o ulpqueue.o \
 	  tsnmap.o bind_addr.o socket.o primitive.o \
 	  output.o input.o debug.o stream.o auth.o \
-	  offload.o
+	  offload.o stream_sched.o
 
 sctp_probe-y := probe.o

net/sctp/outqueue.c +32 ~~-27~~

135 lines not on this page · raw message

net/sctp/sm_sideeffect.c +3 -0

index e6a2974e020e1a4232d94e6c2933eebff5f8acb4..402bfbb888cda53248dd192d3756a2f4db1d2a7f 100644
@@ -50,6 +50,7 @@
 #include <net/sock.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
+#include <net/sctp/stream_sched.h>
 
 static int sctp_cmd_interpreter(enum sctp_event event_type,
 				union sctp_subtype subtype,

@@ -1089,6 +1090,8 @@ static void sctp_cmd_send_msg(struct sctp_association *asoc,
 
 	list_for_each_entry(chunk, &msg->chunks, frag_list)
 		sctp_outq_tail(&asoc->outqueue, chunk, gfp);
+
+	asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
 }

net/sctp/stream.c +81 -7

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net/sctp/stream_sched.c new file +270 -0

270 lines not on this page · raw message

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #7 lore raw

PATCH v2 7/10 sctp: add sockopt to get/set stream scheduler

In reply to Marcelo Ricardo Leitner

As defined per RFC Draft ndata Section 4.3.2, named as SCTP_STREAM_SCHEDULER.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 include/uapi/linux/sctp.h |  1 +
 net/sctp/socket.c         | 75 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)

include/uapi/linux/sctp.h +1 -0

index 4487e7625ddbd48be1868a8292a807ecd0a314bc..0050f10087d224bad87c8c54ad318003381aee12 100644
@@ -122,6 +122,7 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_RESET_ASSOC	120
 #define SCTP_ADD_STREAMS	121
 #define SCTP_SOCKOPT_PEELOFF_FLAGS 122
+#define SCTP_STREAM_SCHEDULER	123
 
 /* PR-SCTP policies */
 #define SCTP_PR_SCTP_NONE	0x0000

net/sctp/socket.c +75 -0

105 lines not on this page · raw message

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #8 lore raw

PATCH v2 8/10 sctp: add sockopt to get/set stream scheduler parameters

In reply to Marcelo Ricardo Leitner

As defined per RFC Draft ndata Section 4.3.3, named as SCTP_STREAM_SCHEDULER_VALUE.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 include/uapi/linux/sctp.h |  7 +++++
 net/sctp/socket.c         | 77 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)

include/uapi/linux/sctp.h +7 -0

index 0050f10087d224bad87c8c54ad318003381aee12..00ac417d2c4f8468ea2aad32e59806be5c5aa08d 100644
@@ -123,6 +123,7 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_ADD_STREAMS	121
 #define SCTP_SOCKOPT_PEELOFF_FLAGS 122
 #define SCTP_STREAM_SCHEDULER	123
+#define SCTP_STREAM_SCHEDULER_VALUE	124
 
 /* PR-SCTP policies */
 #define SCTP_PR_SCTP_NONE	0x0000

@@ -815,6 +816,12 @@ struct sctp_assoc_value {
     uint32_t                assoc_value;
 };
 
+struct sctp_stream_value {
+	sctp_assoc_t assoc_id;
+	uint16_t stream_id;
+	uint16_t stream_value;
+};
+
 /*
  * 7.2.2 Peer Address Information
  *

net/sctp/socket.c +77 -0

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Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #9 lore raw

PATCH v2 9/10 sctp: introduce priority based stream scheduler

In reply to Marcelo Ricardo Leitner

This patch introduces RFC Draft ndata section 3.4 Priority Based Scheduler (SCTP_SS_PRIO).

It works by having a struct sctp_stream_priority for each priority configured. This struct is then enlisted on a queue ordered per priority if, and only if, there is a stream with data queued, so that dequeueing is very straightforward: either finish current datamsg or simply dequeue from the highest priority queued, which is the next stream pointed, and that's it.

If there are multiple streams assigned with the same priority and with data queued, it will do round robin amongst them while respecting datamsgs boundaries (when not using idata chunks), to be reasonably fair.

We intentionally don't maintain a list of priorities nor a list of all streams with the same priority to save memory. The first would mean at least 2 other pointers per priority (which, for 1000 priorities, that can mean 16kB) and the second would also mean 2 other pointers but per stream. As SCTP supports up to 65535 streams on a given asoc, that's 1MB. This impacts when giving a priority to some stream, as we have to find out if the new priority is already being used and if we can free the old one, and also when tearing down.

The new fields in struct sctp_stream_out_ext and sctp_stream are added under a union because that memory is to be shared with other schedulers.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 include/net/sctp/structs.h   |  24 +++
 include/uapi/linux/sctp.h    |   3 +-
 net/sctp/Makefile            |   2 +-
 net/sctp/stream_sched.c      |   3 +
 net/sctp/stream_sched_prio.c | 347 +++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 377 insertions(+), 2 deletions(-)
 create mode 100644 net/sctp/stream_sched_prio.c

include/net/sctp/structs.h +24 -0

index 3c22a30fd71b4ef87419a77cf69b00807a5986bb..40eb8d66a37c3ecee39141dc111663f7aac7326a 100644
@@ -1328,10 +1328,27 @@ struct sctp_inithdr_host {
 	__u32 initial_tsn;
 };
 
+struct sctp_stream_priorities {
+	/* List of priorities scheduled */
+	struct list_head prio_sched;
+	/* List of streams scheduled */
+	struct list_head active;
+	/* The next stream stream in line */
+	struct sctp_stream_out_ext *next;
+	__u16 prio;
+};
+
 struct sctp_stream_out_ext {
 	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
 	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
 	struct list_head outq; /* chunks enqueued by this stream */
+	union {
+		struct {
+			/* Scheduled streams list */
+			struct list_head prio_list;
+			struct sctp_stream_priorities *prio_head;
+		};
+	};
 };
 
 struct sctp_stream_out {

@@ -1351,6 +1368,13 @@ struct sctp_stream {
 	__u16 incnt;
 	/* Current stream being sent, if any */
 	struct sctp_stream_out *out_curr;
+	union {
+		/* Fields used by priority scheduler */
+		struct {
+			/* List of priorities scheduled */
+			struct list_head prio_list;
+		};
+	};
 };
 
 #define SCTP_STREAM_CLOSED		0x00

include/uapi/linux/sctp.h +2 -1

index 00ac417d2c4f8468ea2aad32e59806be5c5aa08d..850fa8b29d7e8163dc4ee88af192309bb2535ae9 100644
@@ -1099,7 +1099,8 @@ struct sctp_add_streams {
 /* SCTP Stream schedulers */
 enum sctp_sched_type {
 	SCTP_SS_FCFS,
-	SCTP_SS_MAX = SCTP_SS_FCFS
+	SCTP_SS_PRIO,
+	SCTP_SS_MAX = SCTP_SS_PRIO
 };
 
 #endif /* _UAPI_SCTP_H */

net/sctp/Makefile +1 -1

index 0f6e6d1d69fd336b4a99f896851b0120f9a0d1e0..647c9cfd4e95be4429d25792e5832d7be2efc5c8 100644
@@ -12,7 +12,7 @@ sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \
 	  inqueue.o outqueue.o ulpqueue.o \
 	  tsnmap.o bind_addr.o socket.o primitive.o \
 	  output.o input.o debug.o stream.o auth.o \
-	  offload.o stream_sched.o
+	  offload.o stream_sched.o stream_sched_prio.o
 
 sctp_probe-y := probe.o

net/sctp/stream_sched.c +3 -0

index 40a9a9de2b98a56786a4c8585f5ad514be9189af..115ddb7651695cca7417cb63004a1a59c93523b8 100644
@@ -121,8 +121,11 @@ static struct sctp_sched_ops sctp_sched_fcfs = {
 
 /* API to other parts of the stack */
 
+extern struct sctp_sched_ops sctp_sched_prio;
+
 struct sctp_sched_ops *sctp_sched_ops[] = {
 	&sctp_sched_fcfs,
+	&sctp_sched_prio,
 };
 
 int sctp_sched_set_sched(struct sctp_association *asoc,

net/sctp/stream_sched_prio.c new file +347 -0

347 lines not on this page · raw message

Signature · 1 line

2.13.5

Marcelo Ricardo Leitner

author maintainer

2017-10-03 22:20 UTC #10 lore raw

PATCH v2 10/10 sctp: introduce round robin stream scheduler

In reply to Marcelo Ricardo Leitner

This patch introduces RFC Draft ndata section 3.2 Priority Based Scheduler (SCTP_SS_RR).

Works by maintaining a list of enqueued streams and tracking the last one used to send data. When the datamsg is done, it switches to the next stream.

See-also: https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13

Tested-by Xin Long <[email protected]>

Signed-off-by Marcelo Ricardo Leitner <[email protected]>

---
 include/net/sctp/structs.h |  11 +++
 include/uapi/linux/sctp.h  |   3 +-
 net/sctp/Makefile          |   3 +-
 net/sctp/stream_sched.c    |   2 +
 net/sctp/stream_sched_rr.c | 201 +++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 218 insertions(+), 2 deletions(-)
 create mode 100644 net/sctp/stream_sched_rr.c

include/net/sctp/structs.h +11 -0

index 40eb8d66a37c3ecee39141dc111663f7aac7326a..16f949eef52fdfd7c90fa15b44093334d1355aaf 100644
@@ -1348,6 +1348,10 @@ struct sctp_stream_out_ext {
 			struct list_head prio_list;
 			struct sctp_stream_priorities *prio_head;
 		};
+		/* Fields used by RR scheduler */
+		struct {
+			struct list_head rr_list;
+		};
 	};
 };

@@ -1374,6 +1378,13 @@ struct sctp_stream {
 			/* List of priorities scheduled */
 			struct list_head prio_list;
 		};
+		/* Fields used by RR scheduler */
+		struct {
+			/* List of streams scheduled */
+			struct list_head rr_list;
+			/* The next stream stream in line */
+			struct sctp_stream_out_ext *rr_next;
+		};
 	};
 };

include/uapi/linux/sctp.h +2 -1

index 850fa8b29d7e8163dc4ee88af192309bb2535ae9..6cd7d416ca406e59d3214976fc425bb805f5c6cc 100644
@@ -1100,7 +1100,8 @@ struct sctp_add_streams {
 enum sctp_sched_type {
 	SCTP_SS_FCFS,
 	SCTP_SS_PRIO,
-	SCTP_SS_MAX = SCTP_SS_PRIO
+	SCTP_SS_RR,
+	SCTP_SS_MAX = SCTP_SS_RR
 };
 
 #endif /* _UAPI_SCTP_H */

net/sctp/Makefile +2 -1

index 647c9cfd4e95be4429d25792e5832d7be2efc5c8..bf90c53977190ff563c2b43af31afb7c431d4534 100644
@@ -12,7 +12,8 @@ sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \
 	  inqueue.o outqueue.o ulpqueue.o \
 	  tsnmap.o bind_addr.o socket.o primitive.o \
 	  output.o input.o debug.o stream.o auth.o \
-	  offload.o stream_sched.o stream_sched_prio.o
+	  offload.o stream_sched.o stream_sched_prio.o \
+	  stream_sched_rr.o
 
 sctp_probe-y := probe.o

net/sctp/stream_sched.c +2 -0

index 115ddb7651695cca7417cb63004a1a59c93523b8..03513a9fa110b5317af4502f98ab37702c1eddb9 100644
@@ -122,10 +122,12 @@ static struct sctp_sched_ops sctp_sched_fcfs = {
 /* API to other parts of the stack */
 
 extern struct sctp_sched_ops sctp_sched_prio;
+extern struct sctp_sched_ops sctp_sched_rr;
 
 struct sctp_sched_ops *sctp_sched_ops[] = {
 	&sctp_sched_fcfs,
 	&sctp_sched_prio,
+	&sctp_sched_rr,
 };
 
 int sctp_sched_set_sched(struct sctp_association *asoc,

net/sctp/stream_sched_rr.c new file +201 -0

201 lines not on this page · raw message

Signature · 1 line

2.13.5

David Miller

maintainer

2017-10-03 23:27 UTC #11 lore raw

In reply to Marcelo Ricardo Leitner

From: Marcelo Ricardo Leitner <[email protected]>
Date: Tue, 3 Oct 2017 19:20:07 -0300

Quoted 15 lines

This patchset introduces the SCTP Stream Schedulers are defined by
https://tools.ietf.org/html/draft-ietf-tsvwg-sctp-ndata-13
It provides 3 schedulers at the moment: FCFS, Priority and Round Robin. The other 3, Round Robin per packet, Fair Capacity and Weighted Fair Capacity will be added later. More specifically, WFQ is required by WebRTC Datachannels.
The draft also defines the idata chunk, allowing a usermsg to be interrupted by another piece of idata from another stream. This patchset *doesn't* include it. It will be posted later by Xin Long. Its integration with this patchset is very simple and it basically only requires a tweak in sctp_sched_dequeue_done(), to ignore datamsg boundaries.

Quoted 5 lines

The first 5 patches are a preparation for the next ones. The most relevant patches are the 4th and 6th ones. More details are available on each patch.
v2: changelog update on patch 3

This doesn't look too scary :-)

Series applied, thanks!