When called by HW offloading drivers, the TC action (e.g
net/sched/act_mirred.c) code uses this_cpu logic, e.g
_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets)
per the kernel documention, preemption should be disabled, add that.
Before the fix, when running with CONFIG_PREEMPT set, we get a
BUG: using smp_processor_id() in preemptible [00000000] code: tc/3793
asserion from the TC action (mirred) stats_update callback.
Fixes: aad7e08d39bd ('net/mlx5e: Hardware offloaded flower filter statistics
support')
Signed-off-by: Or Gerlitz <[email protected]>
---
RFC --> V2
- dropped the RFC mark
- refined the change log according to some info from Jakub Kicinski (thanks!)
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 237bd5b..9dddc65 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -1093,10 +1093,14 @@ int mlx5e_stats_flower(struct mlx5e_priv *priv,
mlx5_fc_query_cached(counter, &bytes, &packets, &lastuse);
+ preempt_disable();
+
tcf_exts_to_list(f->exts, &actions);
list_for_each_entry(a, &actions, list)
tcf_action_stats_update(a, bytes, packets, lastuse);
+ preempt_enable();
+
return 0;
}
--
2.3.7
