diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2025-05-12 11:27:31 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-05-15 15:23:31 +0200 |
| commit | 7fe70c06a182a140be9996b02256d907e114479a (patch) | |
| tree | d8b81af5c49aab013c0dcf8f39481929f8c8bf62 | |
| parent | 3af4cdd67f32529c177b885d4ca491710e961928 (diff) | |
net/sched: act_mirred: Move the recursion counter struct netdev_xmit
mirred_nest_level is a per-CPU variable and relies on disabled BH for its
locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT
this data structure requires explicit locking.
Move mirred_nest_level to struct netdev_xmit as u8, provide wrappers.
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20250512092736.229935-11-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | include/linux/netdevice_xmit.h | 3 | ||||
| -rw-r--r-- | net/sched/act_mirred.c | 28 |
2 files changed, 28 insertions, 3 deletions
diff --git a/include/linux/netdevice_xmit.h b/include/linux/netdevice_xmit.h index 38325e070296..848735b3a7c0 100644 --- a/include/linux/netdevice_xmit.h +++ b/include/linux/netdevice_xmit.h @@ -8,6 +8,9 @@ struct netdev_xmit { #ifdef CONFIG_NET_EGRESS u8 skip_txqueue; #endif +#if IS_ENABLED(CONFIG_NET_ACT_MIRRED) + u8 sched_mirred_nest; +#endif }; #endif diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index 5b3814365924..5f01f567c934 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -30,7 +30,29 @@ static LIST_HEAD(mirred_list); static DEFINE_SPINLOCK(mirred_list_lock); #define MIRRED_NEST_LIMIT 4 -static DEFINE_PER_CPU(unsigned int, mirred_nest_level); + +#ifndef CONFIG_PREEMPT_RT +static u8 tcf_mirred_nest_level_inc_return(void) +{ + return __this_cpu_inc_return(softnet_data.xmit.sched_mirred_nest); +} + +static void tcf_mirred_nest_level_dec(void) +{ + __this_cpu_dec(softnet_data.xmit.sched_mirred_nest); +} + +#else +static u8 tcf_mirred_nest_level_inc_return(void) +{ + return current->net_xmit.sched_mirred_nest++; +} + +static void tcf_mirred_nest_level_dec(void) +{ + current->net_xmit.sched_mirred_nest--; +} +#endif static bool tcf_mirred_is_act_redirect(int action) { @@ -423,7 +445,7 @@ TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, int m_eaction; u32 blockid; - nest_level = __this_cpu_inc_return(mirred_nest_level); + nest_level = tcf_mirred_nest_level_inc_return(); if (unlikely(nest_level > MIRRED_NEST_LIMIT)) { net_warn_ratelimited("Packet exceeded mirred recursion limit on dev %s\n", netdev_name(skb->dev)); @@ -454,7 +476,7 @@ TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, retval); dec_nest_level: - __this_cpu_dec(mirred_nest_level); + tcf_mirred_nest_level_dec(); return retval; } |