diff options
| author | Jonas Köppeler <j.koeppeler@tu-berlin.de> | 2026-01-09 14:15:34 +0100 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2026-01-13 11:54:29 +0100 |
| commit | 1bddd758bac21fbbd8a06af746ec7b6d878a9d2c (patch) | |
| tree | baab399c0e2a912fe31f92c684ae81c0d3f873e2 /include/uapi | |
| parent | 87826c01837c314c3caada33524fc769e58364a9 (diff) | |
net/sched: sch_cake: share shaper state across sub-instances of cake_mq
This commit adds shared shaper state across the cake instances beneath a
cake_mq qdisc. It works by periodically tracking the number of active
instances, and scaling the configured rate by the number of active
queues.
The scan is lockless and simply reads the qlen and the last_active state
variable of each of the instances configured beneath the parent cake_mq
instance. Locking is not required since the values are only updated by
the owning instance, and eventual consistency is sufficient for the
purpose of estimating the number of active queues.
The interval for scanning the number of active queues is set to 200 us.
We found this to be a good tradeoff between overhead and response time.
For a detailed analysis of this aspect see the Netdevconf talk:
https://netdevconf.info/0x19/docs/netdev-0x19-paper16-talk-paper.pdf
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jonas Köppeler <j.koeppeler@tu-berlin.de>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20260109-mq-cake-sub-qdisc-v8-5-8d613fece5d8@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/pkt_sched.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index c2da76e78bad..66e8072f44df 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -1036,6 +1036,7 @@ enum { TCA_CAKE_STATS_DROP_NEXT_US, TCA_CAKE_STATS_P_DROP, TCA_CAKE_STATS_BLUE_TIMER_US, + TCA_CAKE_STATS_ACTIVE_QUEUES, __TCA_CAKE_STATS_MAX }; #define TCA_CAKE_STATS_MAX (__TCA_CAKE_STATS_MAX - 1) |