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authorTim Chen <tim.c.chen@linux.intel.com>2016-11-29 10:43:27 -0800
committerIngo Molnar <mingo@kernel.org>2016-11-30 08:27:08 +0100
commitde966cf4a4fa8d4e0357b08204bc791f34deb3fb (patch)
tree455d257b887ca07f1ef30959feaf28dc3a984f05 /arch/x86/Kconfig
parenta293b3954a9d46cf60073616e8ace3c72e3b2f45 (diff)
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: Tim 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: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/Kconfig')
-rw-r--r--arch/x86/Kconfig22
1 files changed, 16 insertions, 6 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 25950f0ccc33..715c1f3664c4 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -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"