#ifndef ISCSI_TARGET_ERL0_H #define ISCSI_TARGET_ERL0_H #include struct iscsi_cmd; struct iscsi_conn; struct iscsi_session; extern void iscsit_set_dataout_sequence_values(struct iscsi_cmd *); extern int iscsit_check_pre_dataout(struct iscsi_cmd *, unsigned char *); extern int iscsit_check_post_dataout(struct iscsi_cmd *, unsigned char *, u8); extern void iscsit_start_time2retain_handler(struct iscsi_session *); extern int iscsit_stop_time2retain_timer(struct iscsi_session *); extern void iscsit_connection_reinstatement_rcfr(struct iscsi_conn *); extern void iscsit_cause_connection_reinstatement(struct iscsi_conn *, int); extern void iscsit_fall_back_to_erl0(struct iscsi_session *); extern void iscsit_take_action_for_connection_exit(struct iscsi_conn *); #endif /*** ISCSI_TARGET_ERL0_H ***/ it.cgi/linux/net-next.git/'>net-next.git
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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 /include/xen/interface/hvm
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 'include/xen/interface/hvm')