Re: Packet time delays on multi-core systems
From: Eric Dumazet
Date: Fri Oct 01 2010 - 11:28:09 EST
Le vendredi 01 octobre 2010 Ã 18:18 +0400, Alexey Vlasov a Ãcrit :
> NIC statistics:
> rx_packets: 2973717440
> tx_packets: 3032670910
> rx_bytes: 1892633650741
> tx_bytes: 2536130682695
> rx_broadcast: 118773199
> tx_broadcast: 68013
> rx_multicast: 95257
> tx_multicast: 0
> rx_errors: 0
> tx_errors: 0
> tx_dropped: 0
> multicast: 95257
> collisions: 0
> rx_length_errors: 0
> rx_over_errors: 0
> rx_crc_errors: 0
> rx_frame_errors: 0
> rx_no_buffer_count: 7939
> rx_queue_drop_packet_count: 1324025520
> rx_missed_errors: 146631
> tx_aborted_errors: 0
> tx_carrier_errors: 0
> tx_fifo_errors: 0
> tx_heartbeat_errors: 0
> tx_window_errors: 0
> tx_abort_late_coll: 0
> tx_deferred_ok: 0
> tx_single_coll_ok: 0
> tx_multi_coll_ok: 0
> tx_timeout_count: 0
> tx_restart_queue: 50715
> rx_long_length_errors: 0
> rx_short_length_errors: 0
> rx_align_errors: 0
> tx_tcp_seg_good: 344724062
> tx_tcp_seg_failed: 0
> rx_flow_control_xon: 0
> rx_flow_control_xoff: 0
> tx_flow_control_xon: 0
> tx_flow_control_xoff: 0
> rx_long_byte_count: 1892633650741
> rx_csum_offload_good: 2973697420
> rx_csum_offload_errors: 6235
> tx_dma_out_of_sync: 0
> alloc_rx_buff_failed: 0
> tx_smbus: 9327
> rx_smbus: 118531661
> dropped_smbus: 0
> tx_queue_0_packets: 797617475
> tx_queue_0_bytes: 630191908685
> tx_queue_1_packets: 719681297
> tx_queue_1_bytes: 625907304846
> tx_queue_2_packets: 718841556
> tx_queue_2_bytes: 620522418855
> tx_queue_3_packets: 796521255
> tx_queue_3_bytes: 646196024585
> rx_queue_0_packets: 788885797
> rx_queue_0_bytes: 458936338699
> rx_queue_0_drops: 0
> rx_queue_1_packets: 701354604
> rx_queue_1_bytes: 457490536453
> rx_queue_1_drops: 0
> rx_queue_2_packets: 791887663
> rx_queue_2_bytes: 534425333616
> rx_queue_2_drops: 0
> rx_queue_3_packets: 691579028
> rx_queue_3_bytes: 429887244557
> rx_queue_3_drops: 0
> 11.111.80: R 1983626201:1983626201(0) win 0
> > >
OK
IGB stats are wrong... for rx_queue_drop_packet_count field at least
Here is a patch against 2.6.32.23, to get the idea...
Dont trust it unless you patch your kernel ;)
Thanks
Note: current linux-2.6 tree doesnt have this bug.
[PATCH] igb: rx_fifo_errors counter fix
Alexey Vlasov reported insane rx_queue_drop_packet_count
(rx_fifo_errors) values.
IGB drivers is doing an accumulation for 82575, instead using a zero
value for rqdpc_total.
Reported-by: Alexey Vlasov <renton@xxxxxxxxxxx>
Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
---
linux-2.6.32.23/net/igb/igb_main.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- linux-2.6.32.23/drivers/net/igb/igb_main.c.orig
+++ linux-2.6.32.23/drivers/net/igb/igb_main.c
@@ -3552,6 +3552,7 @@
struct e1000_hw *hw = &adapter->hw;
struct pci_dev *pdev = adapter->pdev;
u16 phy_tmp;
+ unsigned long rqdpc_total = 0;
#define PHY_IDLE_ERROR_COUNT_MASK 0x00FF
@@ -3645,7 +3646,6 @@
if (hw->mac.type != e1000_82575) {
u32 rqdpc_tmp;
- u64 rqdpc_total = 0;
int i;
/* Read out drops stats per RX queue. Notice RQDPC (Receive
* Queue Drop Packet Count) stats only gets incremented, if
@@ -3660,7 +3660,6 @@
adapter->rx_ring[i].rx_stats.drops += rqdpc_tmp;
rqdpc_total += adapter->rx_ring[i].rx_stats.drops;
}
- adapter->net_stats.rx_fifo_errors = rqdpc_total;
}
/* Note RNBC (Receive No Buffers Count) is an not an exact
@@ -3668,7 +3667,7 @@
* one of the reason for saving it in rx_fifo_errors, as its
* potentially not a true drop.
*/
- adapter->net_stats.rx_fifo_errors += adapter->stats.rnbc;
+ adapter->net_stats.rx_fifo_errors = rqdpc_total + adapter->stats.rnbc;
/* RLEC on some newer hardware can be incorrect so build
* our own version based on RUC and ROC */
--
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