On Wed, 22 Nov 2017 16:30:41 -0800 Solio Sarabia <solio.sara...@intel.com> wrote:
> The netdevice gso_max_size is exposed to allow users fine-control on > systems with multiple NICs with different GSO buffer sizes, and where > the virtual devices like bridge and veth, need to be aware of the GSO > size of the underlying devices. > > In a virtualized environment, setting the right GSO sizes for physical > and virtual devices makes all TSO work to be on physical NIC, improving > throughput and reducing CPU util. If virtual devices send buffers > greater than what NIC supports, it forces host to do TSO for buffers > exceeding the limit, increasing CPU utilization in host. > > Suggested-by: Shiny Sebastian <shiny.sebast...@intel.com> > Signed-off-by: Solio Sarabia <solio.sara...@intel.com> > --- > In one test scenario with Hyper-V host, Ubuntu 16.04 VM, with Docker > inside VM, and NTttcp sending 40 Gbps from one container, setting the > right gso_max_size values for all network devices in the chain, reduces > CPU overhead about 3x (for the sender), since all TSO work is done by > physical NIC. > > net/core/net-sysfs.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) You probably should expose gso_max_segs as well.
