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: c5ad119fb6 ("net: sched: pfifo_fast use skb_array")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni 2019-03-28 16:53:12 +01:00 committed by David S. Miller
parent 0db6f8befc
commit 5dd431b6b9
11 changed files with 36 additions and 17 deletions

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@ -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;

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@ -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));

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@ -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));

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@ -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));

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@ -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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@ -249,7 +249,7 @@ static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
sch = dev_queue->qdisc_sleeping;
if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL, &sch->qstats, sch->q.qlen) < 0)
qdisc_qstats_copy(d, sch) < 0)
return -1;
return 0;
}

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@ -561,8 +561,7 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
sch = dev_queue->qdisc_sleeping;
if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
d, NULL, &sch->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL,
&sch->qstats, sch->q.qlen) < 0)
qdisc_qstats_copy(d, sch) < 0)
return -1;
}
return 0;

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@ -344,7 +344,7 @@ static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
cl_q = q->queues[cl - 1];
if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
d, NULL, &cl_q->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
qdisc_qstats_copy(d, cl_q) < 0)
return -1;
return 0;

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@ -365,7 +365,7 @@ static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
cl_q = q->queues[cl - 1];
if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
d, NULL, &cl_q->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
qdisc_qstats_copy(d, cl_q) < 0)
return -1;
return 0;

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@ -655,8 +655,7 @@ static int qfq_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, cl->qdisc->q.qlen) < 0)
qdisc_qstats_copy(d, cl->qdisc) < 0)
return -1;
return gnet_stats_copy_app(d, &xstats, sizeof(xstats));

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@ -895,7 +895,7 @@ static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
sch = dev_queue->qdisc_sleeping;
if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
gnet_stats_copy_queue(d, NULL, &sch->qstats, sch->q.qlen) < 0)
qdisc_qstats_copy(d, sch) < 0)
return -1;
return 0;
}