Re: [PATCHv2 4/5] sctp: a sample module of strict priority queue

[Shan Wei <shanwei@cn.fujitsu.com>]

Yaogong Wang wrote, at 09/12/2010 09:13 AM:
> Provide a sample kernel module that uses the pluggable multistream
> scheduling framework. This module implements strict priority queue.
> 
> Signed-off-by: Yaogong Wang <ywang15@ncsu.edu>
> ---
>  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]);

User can using SCTP_SNDRCV option to specific stream number.
So, It is necessary to check stream number with q->asoc->c.sinit_num_ostreams.

> +	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]);

need to check too.
 


-- 
Best Regards
-----
Shan Wei