Subject: Re: [RFC take2] pkt_sched: gen_estimator: Dont report fake rate estimators

From: Jarek Poplawski <[email-masked]>
Date: Fri, 02 Oct 2009 22:11:27 +0200

Eric Dumazet wrote, On 10/02/2009 02:39 PM:

> Jarek Poplawski a écrit :
> 
>> So you prefer the additional parameter version, but since these
>> _active tests are not needed e.g. for HTB classes, which got it
>> active by default, so maybe bstats == NULL would let skip such a test?
>>
>> ...
>>> --- a/include/net/gen_stats.h
>>> +++ b/include/net/gen_stats.h
>>> @@ -30,6 +30,7 @@ extern int gnet_stats_start_copy_compat(struct sk_buff *skb, int type,
>>>  extern int gnet_stats_copy_basic(struct gnet_dump *d,
>>>  				 struct gnet_stats_basic_packed *b);
>>>  extern int gnet_stats_copy_rate_est(struct gnet_dump *d,
>>> +				    const struct gnet_stats_basic_packed *bstats,
>> It seems these *b/*bstats defs could look more consistent. Otherwise
>> it looks OK to me.
> 
> Agreed, here is the updated version, I added your Signoff if you dont mind :)

Hmm... So you made me to do some "real" work here, and guess what?:
there is one serious checkpatch warning! ;-) Plus, this new parameter
should be added to the function description. Otherwise:
Signed-off-by: Jarek Poplawski <[email-masked]>

Thanks,
Jarek P.

PS: I guess full "Don't" would show we really mean it...

> [RFC] pkt_sched: gen_estimator: Dont report fake rate estimators
> 
> We currently send TCA_STATS_RATE_EST elements to netlink users, even if no estimator
> is running.
> 
> # tc -s -d qdisc
> qdisc pfifo_fast 0: dev eth0 root bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
>  Sent 112833764978 bytes 1495081739 pkt (dropped 0, overlimits 0 requeues 0)
>  rate 0bit 0pps backlog 0b 0p requeues 0
> 
> User has no way to tell if the "rate 0bit 0pps" is a real estimation, or a fake
> one (because no estimator is active)
> 
> After this patch, tc command output is :
> $ tc -s -d qdisc
> qdisc pfifo_fast 0: dev eth0 root bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
>  Sent 561075 bytes 1196 pkt (dropped 0, overlimits 0 requeues 0)
>  backlog 0b 0p requeues 0
> 
> We add a parameter to gnet_stats_copy_rate_est() function so that
> it can use gen_estimator_active(bstats, r), as suggested by Jarek.
> 
> This parameter can be NULL if check is not necessary, (htb for
> example has a mandatory rate estimator)
> 
> 
> Signed-off-by: Eric Dumazet <[email-masked]>
> Signed-off-by: Jarek Poplawski <[email-masked]>
> ---
>  include/net/gen_stats.h |    1 +
>  net/core/gen_stats.c    |    7 ++++++-
>  net/sched/act_api.c     |    2 +-
>  net/sched/sch_api.c     |    2 +-
>  net/sched/sch_cbq.c     |    2 +-
>  net/sched/sch_drr.c     |    2 +-
>  net/sched/sch_hfsc.c    |    2 +-
>  net/sched/sch_htb.c     |    2 +-
>  8 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h
> index c148855..eb87a14 100644
> --- a/include/net/gen_stats.h
> +++ b/include/net/gen_stats.h
> @@ -30,6 +30,7 @@ extern int gnet_stats_start_copy_compat(struct sk_buff *skb, int type,
>  extern int gnet_stats_copy_basic(struct gnet_dump *d,
>  				 struct gnet_stats_basic_packed *b);
>  extern int gnet_stats_copy_rate_est(struct gnet_dump *d,
> +				    const struct gnet_stats_basic_packed *b,
>  				    struct gnet_stats_rate_est *r);
>  extern int gnet_stats_copy_queue(struct gnet_dump *d,
>  				 struct gnet_stats_queue *q);
> diff --git a/net/core/gen_stats.c b/net/core/gen_stats.c
> index 8569310..054a49c 100644
> --- a/net/core/gen_stats.c
> +++ b/net/core/gen_stats.c
> @@ -136,8 +136,13 @@ gnet_stats_copy_basic(struct gnet_dump *d, struct gnet_stats_basic_packed *b)
>   * if the room in the socket buffer was not sufficient.
>   */
>  int
> -gnet_stats_copy_rate_est(struct gnet_dump *d, struct gnet_stats_rate_est *r)
> +gnet_stats_copy_rate_est(struct gnet_dump *d,
> +			 const struct gnet_stats_basic_packed *b,
> +			 struct gnet_stats_rate_est *r)
>  {
> +	if (b && !gen_estimator_active(b, r))
> +		return 0;
> +
>  	if (d->compat_tc_stats) {
>  		d->tc_stats.bps = r->bps;
>  		d->tc_stats.pps = r->pps;
> diff --git a/net/sched/act_api.c b/net/sched/act_api.c
> index 2dfb3e7..2b0d5ee 100644
> --- a/net/sched/act_api.c
> +++ b/net/sched/act_api.c
> @@ -618,7 +618,7 @@ int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
>  			goto errout;
>  
>  	if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
> -	    gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
> +	    gnet_stats_copy_rate_est(&d, &h->tcf_bstats, &h->tcf_rate_est) < 0 ||
>  	    gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
>  		goto errout;
>  
> diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
> index 903e418..1acfd29 100644
> --- a/net/sched/sch_api.c
> +++ b/net/sched/sch_api.c
> @@ -1179,7 +1179,7 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
>  		goto nla_put_failure;
>  
>  	if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
> -	    gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 ||
> +	    gnet_stats_copy_rate_est(&d, &q->bstats, &q->rate_est) < 0 ||
>  	    gnet_stats_copy_queue(&d, &q->qstats) < 0)
>  		goto nla_put_failure;
>  
> diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
> index 5b132c4..3846d65 100644
> --- a/net/sched/sch_cbq.c
> +++ b/net/sched/sch_cbq.c
> @@ -1609,7 +1609,7 @@ cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
>  		cl->xstats.undertime = cl->undertime - q->now;
>  
>  	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
> -	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
> +	    gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
>  	    gnet_stats_copy_queue(d, &cl->qstats) < 0)
>  		return -1;
>  
> diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
> index 5a888af..a65604f 100644
> --- a/net/sched/sch_drr.c
> +++ b/net/sched/sch_drr.c
> @@ -280,7 +280,7 @@ static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg,
>  	}
>  
>  	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
> -	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
> +	    gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
>  	    gnet_stats_copy_queue(d, &cl->qdisc->qstats) < 0)
>  		return -1;
>  
> diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
> index 2c5c76b..b38b39c 100644
> --- a/net/sched/sch_hfsc.c
> +++ b/net/sched/sch_hfsc.c
> @@ -1375,7 +1375,7 @@ hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
>  	xstats.rtwork  = cl->cl_cumul;
>  
>  	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
> -	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
> +	    gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
>  	    gnet_stats_copy_queue(d, &cl->qstats) < 0)
>  		return -1;
>  
> diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
> index 85acab9..2e38d1a 100644
> --- a/net/sched/sch_htb.c
> +++ b/net/sched/sch_htb.c
> @@ -1105,7 +1105,7 @@ htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
>  	cl->xstats.ctokens = cl->ctokens;
>  
>  	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
> -	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
> +	    gnet_stats_copy_rate_est(d, NULL, &cl->rate_est) < 0 ||
>  	    gnet_stats_copy_queue(d, &cl->qstats) < 0)
>  		return -1;
>  
> --
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