From: Konstantin Khlebnikov Date: Mon, 6 Apr 2020 11:39:32 +0000 (+0300) Subject: net: revert default NAPI poll timeout to 2 jiffies X-Git-Tag: v4.19.117~35 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f7379c0050d2bfb65e44b340f1d667254dcc3058;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/net/core/dev.c b/net/core/dev.c index 2f4d35101f4df..426635e188fc1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3934,7 +3934,8 @@ 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 */