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authorJohn Fastabend <john.fastabend@gmail.com>2014-09-28 11:52:56 -0700
committerDavid S. Miller <davem@davemloft.net>2014-09-30 01:02:26 -0400
commit22e0f8b9322cb1a48b1357e8f4ae6f5a9eca8cfa (patch)
tree2c9ef18dca9d9a441d92ea57cf7f7a292f4ceb3f /net/sched/sch_api.c
parent79cf79abce71eb7dbc40e2f3121048ca5405cb47 (diff)
downloadop-kernel-dev-22e0f8b9322cb1a48b1357e8f4ae6f5a9eca8cfa.zip
op-kernel-dev-22e0f8b9322cb1a48b1357e8f4ae6f5a9eca8cfa.tar.gz
net: sched: make bstats per cpu and estimator RCU safe
In order to run qdisc's without locking statistics and estimators need to be handled correctly. To resolve bstats make the statistics per cpu. And because this is only needed for qdiscs that are running without locks which is not the case for most qdiscs in the near future only create percpu stats when qdiscs set the TCQ_F_CPUSTATS flag. Next because estimators use the bstats to calculate packets per second and bytes per second the estimator code paths are updated to use the per cpu statistics. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_api.c')
-rw-r--r--net/sched/sch_api.c29
1 files changed, 23 insertions, 6 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 15e7bee..a95e3b4 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -942,6 +942,13 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
sch->handle = handle;
if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
+ if (qdisc_is_percpu_stats(sch)) {
+ sch->cpu_bstats =
+ alloc_percpu(struct gnet_stats_basic_cpu);
+ if (!sch->cpu_bstats)
+ goto err_out4;
+ }
+
if (tca[TCA_STAB]) {
stab = qdisc_get_stab(tca[TCA_STAB]);
if (IS_ERR(stab)) {
@@ -964,8 +971,11 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
else
root_lock = qdisc_lock(sch);
- err = gen_new_estimator(&sch->bstats, &sch->rate_est,
- root_lock, tca[TCA_RATE]);
+ err = gen_new_estimator(&sch->bstats,
+ sch->cpu_bstats,
+ &sch->rate_est,
+ root_lock,
+ tca[TCA_RATE]);
if (err)
goto err_out4;
}
@@ -984,6 +994,7 @@ err_out:
return NULL;
err_out4:
+ free_percpu(sch->cpu_bstats);
/*
* Any broken qdiscs that would require a ops->reset() here?
* The qdisc was never in action so it shouldn't be necessary.
@@ -1022,9 +1033,11 @@ static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
because change can't be undone. */
if (sch->flags & TCQ_F_MQROOT)
goto out;
- gen_replace_estimator(&sch->bstats, &sch->rate_est,
- qdisc_root_sleeping_lock(sch),
- tca[TCA_RATE]);
+ gen_replace_estimator(&sch->bstats,
+ sch->cpu_bstats,
+ &sch->rate_est,
+ qdisc_root_sleeping_lock(sch),
+ tca[TCA_RATE]);
}
out:
return 0;
@@ -1299,6 +1312,7 @@ graft:
static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
u32 portid, u32 seq, u16 flags, int event)
{
+ struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL;
struct tcmsg *tcm;
struct nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);
@@ -1334,7 +1348,10 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
goto nla_put_failure;
- if (gnet_stats_copy_basic(&d, &q->bstats) < 0 ||
+ if (qdisc_is_percpu_stats(q))
+ cpu_bstats = q->cpu_bstats;
+
+ if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats) < 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;
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