#!/bin/sh TEST_FILE=$(mktemp) echo "== Testing sysctl behavior against ${TARGET} ==" set_orig() { echo "${ORIG}" > "${TARGET}" } set_test() { echo "${TEST_STR}" > "${TARGET}" } verify() { local seen seen=$(cat "$1") if [ "${seen}" != "${TEST_STR}" ]; then return 1 fi return 0 } trap 'set_orig; rm -f "${TEST_FILE}"' EXIT rc=0 echo -n "Writing test file ... " echo "${TEST_STR}" > "${TEST_FILE}" if ! verify "${TEST_FILE}"; then echo "FAIL" >&2 exit 1 else echo "ok" fi echo -n "Checking sysctl is not set to test value ... " if verify "${TARGET}"; then echo "FAIL" >&2 exit 1 else echo "ok" fi echo -n "Writing sysctl from shell ... " set_test if ! verify "${TARGET}"; then echo "FAIL" >&2 exit 1 else echo "ok" fi echo -n "Resetting sysctl to original value ... " set_orig if verify "${TARGET}"; then echo "FAIL" >&2 exit 1 else echo "ok" fi # Now that we've validated the sanity of "set_test" and "set_orig", # we can use those functions to set starting states before running # specific behavioral tests. echo -n "Writing entire sysctl in single write ... " set_orig dd if="${TEST_FILE}" of="${TARGET}" bs=4096 2>/dev/null if ! verify "${TARGET}"; then echo "FAIL" >&2 rc=1 else echo "ok" fi echo -n "Writing middle of sysctl after synchronized seek ... " set_test dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 skip=1 2>/dev/null if ! verify "${TARGET}"; then echo "FAIL" >&2 rc=1 else echo "ok" fi echo -n "Writing beyond end of sysctl ... " set_orig dd if="${TEST_FILE}" of="${TARGET}" bs=20 seek=2 2>/dev/null if verify "${TARGET}"; then echo "FAIL" >&2 rc=1 else echo "ok" fi echo -n "Writing sysctl with multiple long writes ... " set_orig (perl -e 'print "A" x 50;'; echo "${TEST_STR}") | \ dd of="${TARGET}" bs=50 2>/dev/null if verify "${TARGET}"; then echo "FAIL" >&2 rc=1 else echo "ok" fi r/debug/kernel/Makefile?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>treecommitdiff
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authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2017-02-03 14:18:39 -0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-02-04 00:11:08 +0100
commit6e978b22efa1db9f6e71b24440b5f1d93e968ee3 (patch)
treec666f7a26b860674848949e39a610222b0723f89 /tools/power/cpupower/debug/kernel/Makefile
parent3c223c19aea85d3dda1416c187915f4a30b04b1f (diff)
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>
Diffstat (limited to 'tools/power/cpupower/debug/kernel/Makefile')