Hi
Patch applied but no change still 100% CPU
perf below:
1.99% 0.00% ksoftirqd/1 [kernel.vmlinux] [k] run_ksoftirqd
|
---run_ksoftirqd
|
--1.99%--__softirqentry_text_start
|
--1.99%--net_rx_action
|
--1.98%--mlx5e_napi_poll
|
--1.98%--mlx5e_poll_rx_cq
|
--1.98%--mlx5e_handle_rx_cqe
|
--1.96%--napi_gro_receive
|
--1.96%--netif_receive_skb_internal
|
--1.96%--__netif_receive_skb
|
--1.96%--__netif_receive_skb_core
|
--1.95%--ip_rcv
|
--1.95%--ip_rcv_finish
|
--1.94%--ip_forward
|
--1.94%--ip_forward_finish
|
--1.94%--ip_output
|
--1.94%--ip_finish_output
|
--1.94%--ip_finish_output2
|
--1.90%--neigh_resolve_output
|
--1.90%--neigh_event_send
|
--1.90%--__neigh_event_send
|
--1.87%--_raw_write_lock_bh
queued_write_lock
queued_write_lock_slowpath
|
--1.84%--queued_spin_lock_slowpath
W dniu 2017-08-15 o 21:11, Eric Dumazet pisze:
On Tue, 2017-08-15 at 19:42 +0200, Paweł Staszewski wrote:
# To display the perf.data header info, please use
--header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 2M of event 'cycles'
# Event count (approx.): 1585571545969
#
# Children Self Command Shared Object Symbol
# ........ ........ .............. ....................
..............................................
#
1.82% 0.00% ksoftirqd/43 [kernel.vmlinux] [k]
__softirqentry_text_start
|
--1.82%--__softirqentry_text_start
|
--1.82%--net_rx_action
|
--1.82%--mlx5e_napi_poll
|
--1.81%--mlx5e_poll_rx_cq
|
--1.81%--mlx5e_handle_rx_cqe
|
--1.79%--napi_gro_receive
|
--1.78%--netif_receive_skb_internal
|
--1.78%--__netif_receive_skb
|
--1.78%--__netif_receive_skb_core
|
--1.78%--ip_rcv
|
--1.78%--ip_rcv_finish
|
--1.76%--ip_forward
|
--1.76%--ip_forward_finish
|
--1.76%--ip_output
|
--1.76%--ip_finish_output
|
--1.76%--ip_finish_output2
|
--1.73%--neigh_resolve_output
|
--1.73%--neigh_event_send
|
--1.73%--__neigh_event_send
|
--1.70%--_raw_write_lock_bh
queued_write_lock
queued_write_lock_slowpath
|
--1.67%--queued_spin_lock_slowpath
Please try this :
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index
16a1a4c4eb57fa1147f230916e2e62e18ef89562..95e0d7702029b583de8229e3c3eb923f6395b072
100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -991,14 +991,18 @@ static void neigh_timer_handler(unsigned long arg)
int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
{
- int rc;
bool immediate_probe = false;
+ int rc;
+
+ /* We _should_ test this under write_lock_bh(&neigh->lock),
+ * but this is too costly.
+ */
+ if (READ_ONCE(neigh->nud_state) & (NUD_CONNECTED | NUD_DELAY |
NUD_PROBE))
+ return 0;
write_lock_bh(&neigh->lock);
rc = 0;
- if (neigh->nud_state & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))
- goto out_unlock_bh;
if (neigh->dead)
goto out_dead;
