Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning
authorMatthew Whitehead <tedheadster@gmail.com>
Wed, 19 Apr 2017 16:37:10 +0000 (12:37 -0400)
committerDavid S. Miller <davem@davemloft.net>
Fri, 21 Apr 2017 17:22:34 +0000 (13:22 -0400)
commit7acf8a1e8a28b3d7407a8d8061a7d0766cfac2f4
tree34fb2d27d86e816f25b4a41f0d5d6b8d837f5bd9
parent20da848f8e5c2d911ee65dda1776d0f2a2408e01
Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning

Constants used for tuning are generally a bad idea, especially as hardware
changes over time. Replace the constant 2 jiffies with sysctl variable
netdev_budget_usecs to enable sysadmins to tune the softirq processing.
Also document the variable.

For example, a very fast machine might tune this to 1000 microseconds,
while my regression testing 486DX-25 needs it to be 4000 microseconds on
a nearly idle network to prevent time_squeeze from being incremented.

Version 2: changed jiffies to microseconds for predictable units.

Signed-off-by: Matthew Whitehead <tedheadster@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Documentation/sysctl/net.txt
include/linux/netdevice.h
include/uapi/linux/sysctl.h
kernel/sysctl_binary.c
net/core/dev.c
net/core/sysctl_net_core.c