Commit de966cf4 authored by Tim Chen's avatar Tim Chen Committed by Ingo Molnar
Browse files

sched/x86: Change CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO 



Rename CONFIG_SCHED_ITMT for Intel Turbo Boost Max Technology 3.0
to CONFIG_SCHED_MC_PRIO.  This makes the configuration extensible
in future to other architectures that wish to similarly establish
CPU core priorities support in the scheduler.

The description in Kconfig is updated to reflect this change with
added details for better clarity.  The configuration is explicitly
default-y, to enable the feature on CPUs that have this feature.

It has no effect on non-TBM3 CPUs.

Signed-off-by: default avatarTim Chen <tim.c.chen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@suse.de
Cc: jolsa@redhat.com
Cc: linux-acpi@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: rjw@rjwysocki.net
Link: http://lkml.kernel.org/r/2b2ee29d93e3f162922d72d0165a1405864fbb23.1480444902.git.tim.c.chen@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent a293b395

arch/x86/Kconfig

+16 −6
Original line number Diff line number Diff line
@@ -939,14 +939,24 @@ config SCHED_MC 
	  making when dealing with multi-core CPU chips at a cost of slightly

	  increased overhead in some places. If unsure say N here.



config SCHED_ITMT

	bool "Intel Turbo Boost Max Technology (ITMT) scheduler support"

config SCHED_MC_PRIO

	bool "CPU core priorities scheduler support"

	depends on SCHED_MC && CPU_SUP_INTEL && X86_INTEL_PSTATE

	default y

	---help---

	  ITMT enabled scheduler support improves the CPU scheduler's decision

	  to move tasks to cpu core that can be boosted to a higher frequency

	  than others. It will have better performance at a cost of slightly

	  increased overhead in task migrations. If unsure say N here.

	   Intel Turbo Boost Max Technology 3.0 enabled CPUs have a

	   core ordering determined at manufacturing time, which allows

	   certain cores to reach higher turbo frequencies (when running

	   single threaded workloads) than others.



	   Enabling this kernel feature teaches the scheduler about

	   the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the

	   scheduler's CPU selection logic accordingly, so that higher

	   overall system performance can be achieved.



	   This feature will have no effect on CPUs without this feature.



	   If unsure say Y here.



source "kernel/Kconfig.preempt"

arch/x86/include/asm/topology.h

+3 −3
Original line number Diff line number Diff line
@@ -148,7 +148,7 @@ void x86_pci_root_bus_resources(int bus, struct list_head *resources); 


extern bool x86_topology_update;



#ifdef CONFIG_SCHED_ITMT

#ifdef CONFIG_SCHED_MC_PRIO

#include <asm/percpu.h>



DECLARE_PER_CPU_READ_MOSTLY(int, sched_core_priority);
@@ -163,7 +163,7 @@ int sched_set_itmt_support(void); 
/* Interface to notify scheduler that system revokes ITMT support */

void sched_clear_itmt_support(void);



#else /* CONFIG_SCHED_ITMT */

#else /* CONFIG_SCHED_MC_PRIO */



#define sysctl_sched_itmt_enabled	0

static inline void sched_set_itmt_core_prio(int prio, int core_cpu)
@@ -176,6 +176,6 @@ static inline int sched_set_itmt_support(void) 
static inline void sched_clear_itmt_support(void)

{

}

#endif /* CONFIG_SCHED_ITMT */

#endif /* CONFIG_SCHED_MC_PRIO */



#endif /* _ASM_X86_TOPOLOGY_H */

arch/x86/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -123,7 +123,7 @@ obj-$(CONFIG_EFI) += sysfb_efi.o 


obj-$(CONFIG_PERF_EVENTS)		+= perf_regs.o

obj-$(CONFIG_TRACING)			+= tracepoint.o

obj-$(CONFIG_SCHED_ITMT)		+= itmt.o

obj-$(CONFIG_SCHED_MC_PRIO)		+= itmt.o



ifdef CONFIG_FRAME_POINTER

obj-y					+= unwind_frame.o

drivers/acpi/bus.c

+1 −1
Original line number Diff line number Diff line
@@ -338,7 +338,7 @@ static void acpi_bus_osc_support(void) 
	}

#endif



	if (IS_ENABLED(CONFIG_SCHED_ITMT))

	if (IS_ENABLED(CONFIG_SCHED_MC_PRIO))

		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_DIVERSE_HIGH_SUPPORT;



	if (!ghes_disable)

drivers/cpufreq/Kconfig.x86

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ config X86_INTEL_PSTATE 
       bool "Intel P state control"

       depends on X86

       select ACPI_PROCESSOR if ACPI

       select ACPI_CPPC_LIB if X86_64 && ACPI && SCHED_ITMT

       select ACPI_CPPC_LIB if X86_64 && ACPI && SCHED_MC_PRIO

       help

          This driver provides a P state for Intel core processors.

	  The driver implements an internal governor and will become

CRA Git | Maintained and supported by SUSTech CRA and CCSE