| From foo@baz Sat 18 Apr 2020 11:09:57 AM CEST |
| From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> |
| Date: Mon, 6 Apr 2020 14:39:32 +0300 |
| Subject: net: revert default NAPI poll timeout to 2 jiffies |
| |
| From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> |
| |
| [ Upstream commit a4837980fd9fa4c70a821d11831698901baef56b ] |
| |
| For HZ < 1000 timeout 2000us rounds up to 1 jiffy but expires randomly |
| because next timer interrupt could come shortly after starting softirq. |
| |
| For commonly used CONFIG_HZ=1000 nothing changes. |
| |
| Fixes: 7acf8a1e8a28 ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning") |
| Reported-by: Dmitry Yakunin <zeil@yandex-team.ru> |
| Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/core/dev.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/net/core/dev.c |
| +++ b/net/core/dev.c |
| @@ -3863,7 +3863,8 @@ EXPORT_SYMBOL(netdev_max_backlog); |
| |
| int netdev_tstamp_prequeue __read_mostly = 1; |
| int netdev_budget __read_mostly = 300; |
| -unsigned int __read_mostly netdev_budget_usecs = 2000; |
| +/* Must be at least 2 jiffes to guarantee 1 jiffy timeout */ |
| +unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ; |
| int weight_p __read_mostly = 64; /* old backlog weight */ |
| int dev_weight_rx_bias __read_mostly = 1; /* bias for backlog weight */ |
| int dev_weight_tx_bias __read_mostly = 1; /* bias for output_queue quota */ |
