Revision 6e474083f3daf3a3546737f5d7d502ad12eb257c authored by Wei Xu on 01 December 2017, 10:10:36 UTC, committed by David S. Miller on 03 December 2017, 02:31:03 UTC
Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev@vger.kernel.org/msg187936.html Eventually we figured out that it was a skb leak in handle_rx() when sending packets to the VM. This usually happens when a guest can not drain out vq as fast as vhost fills in, afterwards it sets off the traffic jam and leaks skb(s) which occurs as no headcount to send on the vq from vhost side. This can be avoided by making sure we have got enough headcount before actually consuming a skb from the batched rx array while transmitting, which is simply done by moving checking the zero headcount a bit ahead. Signed-off-by: Wei Xu <wexu@redhat.com> Reported-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Kconfig
#
# STMicroelectonics LIS3LV02D and similar accelerometers
#
config SENSORS_LIS3_SPI
tristate "STMicroeletronics LIS3LV02Dx three-axis digital accelerometer (SPI)"
depends on !ACPI && SPI_MASTER && INPUT
select SENSORS_LIS3LV02D
default n
help
This driver provides support for the LIS3LV02Dx accelerometer connected
via SPI. The accelerometer data is readable via
/sys/devices/platform/lis3lv02d.
This driver also provides an absolute input class device, allowing
the laptop to act as a pinball machine-esque joystick.
This driver can also be built as modules. If so, the core module
will be called lis3lv02d and a specific module for the SPI transport
is called lis3lv02d_spi.
config SENSORS_LIS3_I2C
tristate "STMicroeletronics LIS3LV02Dx three-axis digital accelerometer (I2C)"
depends on I2C && INPUT
select SENSORS_LIS3LV02D
default n
help
This driver provides support for the LIS3LV02Dx accelerometer connected
via I2C. The accelerometer data is readable via
/sys/devices/platform/lis3lv02d.
This driver also provides an absolute input class device, allowing
the device to act as a pinball machine-esque joystick.
This driver can also be built as modules. If so, the core module
will be called lis3lv02d and a specific module for the I2C transport
is called lis3lv02d_i2c.
![swh spinner](/static/img/swh-spinner.gif)
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