diff options
| author | Netanel Belgazal <netanel@amazon.com> | 2017-06-11 15:42:48 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-11 23:36:46 +0300 |
| commit | a3af7c18cfe545a711e5df7491b7d6df71eba2ff (patch) | |
| tree | eb7c182c442a68f6c11d4b675df977ceb134b240 /drivers/net/ethernet/amazon/ena/ena_netdev.h | |
| parent | 0857d92f71b6cb75281fde913554b2d5436c394b (diff) | |
| download | linux-a3af7c18cfe545a711e5df7491b7d6df71eba2ff.tar.xz | |
net: ena: fix theoretical Rx hang on low memory systems
For the rare case where the device runs out of free rx buffer
descriptors (in case of pressure on kernel memory),
and the napi handler continuously fail to refill new Rx descriptors
until device rx queue totally runs out of all free rx buffers
to post incoming packet, leading to a deadlock:
* The device won't send interrupts since all the new
Rx packets will be dropped.
* The napi handler won't try to allocate new Rx descriptors
since allocation is part of NAPI that's not being invoked any more
The fix involves detecting this scenario and rescheduling NAPI
(to refill buffers) by the keepalive/watchdog task.
Fixes: 1738cd3ed342 ("Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/amazon/ena/ena_netdev.h')
| -rw-r--r-- | drivers/net/ethernet/amazon/ena/ena_netdev.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h index 0e22bce6239d..8828f1d6dd22 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.h +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h @@ -184,6 +184,7 @@ struct ena_stats_rx { u64 dma_mapping_err; u64 bad_desc_num; u64 rx_copybreak_pkt; + u64 empty_rx_ring; }; struct ena_ring { @@ -231,6 +232,7 @@ struct ena_ring { struct ena_stats_tx tx_stats; struct ena_stats_rx rx_stats; }; + int empty_rx_queue; } ____cacheline_aligned; struct ena_stats_dev { |