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| author | Paolo Abeni <pabeni@redhat.com> | 2019-04-10 14:32:40 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-04-10 12:20:46 -0700 |
| commit | 8a53e616de294873fec1a75ddb77ecb3d225cee0 (patch) | |
| tree | 417d298678e0f2bba183375d0754ff2f8ccbe19e /net/sched/sch_api.c | |
| parent | 9c01c9f1f2a3ddbddbf3b233cc6bfa86f5a59af0 (diff) | |
| download | linux-8a53e616de294873fec1a75ddb77ecb3d225cee0.tar.bz2 | |
net: sched: when clearing NOLOCK, clear TCQ_F_CPUSTATS, too
Since stats updating is always consistent with TCQ_F_CPUSTATS flag,
we can disable it at qdisc creation time flipping such bit.
In my experiments, if the NOLOCK flag is cleared, per CPU stats
accounting does not give any measurable performance gain, but it
waste some memory.
Let's clear TCQ_F_CPUSTATS together with NOLOCK, when enslaving
a NOLOCK qdisc to 'lock' one.
Use stats update helper inside pfifo_fast, to cope correctly with
TCQ_F_CPUSTATS flag change.
As a side effect, q.qlen value for any child qdiscs is always
consistent for all lock classfull qdiscs.
Signed-off-by: Paolo Abeni <pabeni@redhat.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.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index fb8f138b9776..c126b9f78d6e 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -998,6 +998,19 @@ static void notify_and_destroy(struct net *net, struct sk_buff *skb, qdisc_put(old); } +static void qdisc_clear_nolock(struct Qdisc *sch) +{ + sch->flags &= ~TCQ_F_NOLOCK; + if (!(sch->flags & TCQ_F_CPUSTATS)) + return; + + free_percpu(sch->cpu_bstats); + free_percpu(sch->cpu_qstats); + sch->cpu_bstats = NULL; + sch->cpu_qstats = NULL; + sch->flags &= ~TCQ_F_CPUSTATS; +} + /* Graft qdisc "new" to class "classid" of qdisc "parent" or * to device "dev". * @@ -1076,7 +1089,7 @@ skip: /* Only support running class lockless if parent is lockless */ if (new && (new->flags & TCQ_F_NOLOCK) && parent && !(parent->flags & TCQ_F_NOLOCK)) - new->flags &= ~TCQ_F_NOLOCK; + qdisc_clear_nolock(new); if (!cops || !cops->graft) return -EOPNOTSUPP; |