Commit 5dd431b6 authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

net: sched: introduce and use qstats read helpers 



Classful qdiscs can't access directly the child qdiscs backlog
length: if such qdisc is NOLOCK, per CPU values should be
accounted instead.

Most qdiscs no not respect the above. As a result, qstats fetching
for most classful qdisc is currently incorrect: if the child qdisc is
NOLOCK, it always reports 0 len backlog.

This change introduces a pair of helpers to safely fetch
both backlog and qlen and use them in stats class dumping
functions, fixing the above issue and cleaning a bit the code.

DRR needs also to access the child qdisc queue length, so it
needs custom handling.

Fixes: c5ad119f ("net: sched: pfifo_fast use skb_array")
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0db6f8be

include/net/sch_generic.h

+18 −0
Original line number Diff line number Diff line
@@ -923,6 +923,24 @@ static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 
	sch->qstats.overlimits++;

}



static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)

{

	__u32 qlen = qdisc_qlen_sum(sch);



	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);

}



static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,

					     __u32 *backlog)

{

	struct gnet_stats_queue qstats = { 0 };

	__u32 len = qdisc_qlen_sum(sch);



	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);

	*qlen = qstats.qlen;

	*backlog = qstats.backlog;

}



static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)

{

	qh->head = NULL;

net/sched/sch_cbq.c

+3 −1
Original line number Diff line number Diff line
@@ -1358,9 +1358,11 @@ cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg, 
{

	struct cbq_sched_data *q = qdisc_priv(sch);

	struct cbq_class *cl = (struct cbq_class *)arg;

	__u32 qlen;



	cl->xstats.avgidle = cl->avgidle;

	cl->xstats.undertime = 0;

	qdisc_qstats_qlen_backlog(cl->q, &qlen, &cl->qstats.backlog);



	if (cl->undertime != PSCHED_PASTPERFECT)

		cl->xstats.undertime = cl->undertime - q->now;
@@ -1368,7 +1370,7 @@ cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg, 
	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),

				  d, NULL, &cl->bstats) < 0 ||

	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||

	    gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->q->q.qlen) < 0)

	    gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)

		return -1;



	return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));

net/sched/sch_drr.c

+3 −2
Original line number Diff line number Diff line
@@ -269,7 +269,8 @@ static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg, 
				struct gnet_dump *d)

{

	struct drr_class *cl = (struct drr_class *)arg;

	__u32 qlen = cl->qdisc->q.qlen;

	__u32 qlen = qdisc_qlen_sum(cl->qdisc);

	struct Qdisc *cl_q = cl->qdisc;

	struct tc_drr_stats xstats;



	memset(&xstats, 0, sizeof(xstats));
@@ -279,7 +280,7 @@ static int drr_dump_class_stats(struct Qdisc *sch, unsigned long arg, 
	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),

				  d, NULL, &cl->bstats) < 0 ||

	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||

	    gnet_stats_copy_queue(d, NULL, &cl->qdisc->qstats, qlen) < 0)

	    gnet_stats_copy_queue(d, cl_q->cpu_qstats, &cl_q->qstats, qlen) < 0)

		return -1;



	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));

net/sched/sch_hfsc.c

+3 −2
Original line number Diff line number Diff line
@@ -1328,8 +1328,9 @@ hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg, 
{

	struct hfsc_class *cl = (struct hfsc_class *)arg;

	struct tc_hfsc_stats xstats;

	__u32 qlen;



	cl->qstats.backlog = cl->qdisc->qstats.backlog;

	qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);

	xstats.level   = cl->level;

	xstats.period  = cl->cl_vtperiod;

	xstats.work    = cl->cl_total;
@@ -1337,7 +1338,7 @@ hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg, 


	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d, NULL, &cl->bstats) < 0 ||

	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||

	    gnet_stats_copy_queue(d, NULL, &cl->qstats, cl->qdisc->q.qlen) < 0)

	    gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)

		return -1;



	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));

net/sched/sch_htb.c

+3 −4
Original line number Diff line number Diff line
@@ -1127,10 +1127,9 @@ htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) 
	};

	__u32 qlen = 0;



	if (!cl->level && cl->leaf.q) {

		qlen = cl->leaf.q->q.qlen;

		qs.backlog = cl->leaf.q->qstats.backlog;

	}

	if (!cl->level && cl->leaf.q)

		qdisc_qstats_qlen_backlog(cl->leaf.q, &qlen, &qs.backlog);



	cl->xstats.tokens = clamp_t(s64, PSCHED_NS2TICKS(cl->tokens),

				    INT_MIN, INT_MAX);

	cl->xstats.ctokens = clamp_t(s64, PSCHED_NS2TICKS(cl->ctokens),

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