From f6b264f2a04c7be92a11819961970d16c91449da Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Mon, 6 Apr 2020 14:39:32 +0300 Subject: [PATCH] net: revert default NAPI poll timeout to 2 jiffies [ 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 Signed-off-by: Konstantin Khlebnikov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index c19c424197e3..8ad1e8f00958 100644 --- 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 */