menuconfig IP_DCCP
tristate "The DCCP Protocol"
depends on INET
---help---
Datagram Congestion Control Protocol (RFC 4340)
From http://www.ietf.org/rfc/rfc4340.txt:
The Datagram Congestion Control Protocol (DCCP) is a transport
protocol that implements bidirectional, unicast connections of
congestion-controlled, unreliable datagrams. It should be suitable
for use by applications such as streaming media, Internet telephony,
and on-line games.
To compile this protocol support as a module, choose M here: the
module will be called dccp.
If in doubt, say N.
if IP_DCCP
config INET_DCCP_DIAG
depends on INET_DIAG
def_tristate y if (IP_DCCP = y && INET_DIAG = y)
def_tristate m
source "net/dccp/ccids/Kconfig"
menu "DCCP Kernel Hacking"
depends on DEBUG_KERNEL=y
config IP_DCCP_DEBUG
bool "DCCP debug messages"
---help---
Only use this if you're hacking DCCP.
When compiling DCCP as a module, this debugging output can be toggled
by setting the parameter dccp_debug of the `dccp' module to 0 or 1.
Just say N.
config NET_DCCPPROBE
tristate "DCCP connection probing"
depends on PROC_FS && KPROBES
---help---
This module allows for capturing the changes to DCCP connection
state in response to incoming packets. It is used for debugging
DCCP congestion avoidance modules. If you don't understand
what was just said, you don't need it: say N.
Documentation on how to use DCCP connection probing can be found
at:
http://www.linuxfoundation.org/collaborate/workgroups/networking/dccpprobe
To compile this code as a module, choose M here: the
module will be called dccp_probe.
endmenu
endif # IP_DDCP
href='/cgit.cgi/linux/net-next.git/refs/?h=nds-private-remove&id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>refslogtreecommitdiff
cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.
This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.
It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.
On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.
Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.
There are several ways to address this problem.
First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.
Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.
Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".
Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>