file: /proc/sys/net/core/dev_weight_tx_bias
variable: net.core.dev_weight_tx_bias
Official reference

Scales the maximum number of packets that can be processed during a TX softirq cycle. Effective on a per CPU basis. Allows scaling of current dev_weight for asymmetric net stack processing needs. Be careful to avoid making TX softirq processing a CPU hog. Calculation is based on dev_weight (dev_weight * dev_weight_tx_bias). Default: 1