From: Sameeh Jubran Date: Wed, 1 May 2019 16:47:08 +0300 Subject: [PATCH] net: ena: improve latency by disabling adaptive interrupt moderation by default Origin: https://git.kernel.org/linus/78cb421d185cfb4fcea94e7c3ff6e6ea77bb8c11 Bug-Debian: https://bugs.debian.org/941291 Adaptive interrupt moderation was erroneously enabled by default in the driver. In case the device supports adaptive interrupt moderation it will be automatically used, which may potentially increase latency. The adaptive moderation can be enabled from ethtool command in case the feature is supported by the device. Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)") Signed-off-by: Guy Tzalik Signed-off-by: Sameeh Jubran Signed-off-by: David S. Miller --- drivers/net/ethernet/amazon/ena/ena_com.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) Index: linux/drivers/net/ethernet/amazon/ena/ena_com.c =================================================================== --- linux.orig/drivers/net/ethernet/amazon/ena/ena_com.c +++ linux/drivers/net/ethernet/amazon/ena/ena_com.c @@ -2801,7 +2801,11 @@ int ena_com_init_interrupt_moderation(st /* if moderation is supported by device we set adaptive moderation */ delay_resolution = get_resp.u.intr_moderation.intr_delay_resolution; ena_com_update_intr_delay_resolution(ena_dev, delay_resolution); - ena_com_enable_adaptive_moderation(ena_dev); + + /* Disable adaptive moderation by default - can be enabled from + * ethtool + */ + ena_com_disable_adaptive_moderation(ena_dev); return 0; err: