x86/sysctl: Add sysctl for ITMT scheduling feature
authorTim Chen <tim.c.chen@linux.intel.com>
Tue, 22 Nov 2016 20:23:56 +0000 (12:23 -0800)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 24 Nov 2016 19:44:19 +0000 (20:44 +0100)
commitf9793e34952cda133caaa35738a4b46053331c96
tree190366f26441bc5f2f06119cf8510c6dea2a909b
parent5e76b2ab36b40ca33023e78725bdc69eafd63134
x86/sysctl: Add sysctl for ITMT scheduling feature

Intel Turbo Boost Max Technology 3.0 (ITMT) feature
allows some cores to be boosted to higher turbo
frequency than others.

Add /proc/sys/kernel/sched_itmt_enabled so operator
can enable/disable scheduling of tasks that favor cores
with higher turbo boost frequency potential.

By default, system that is ITMT capable and single
socket has this feature turned on.  It is more likely
to be lightly loaded and operates in Turbo range.

When there is a change in the ITMT scheduling operation
desired, a rebuild of the sched domain is initiated
so the scheduler can set up sched domains with appropriate
flag to enable/disable ITMT scheduling operations.

Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-pm@vger.kernel.org
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/07cc62426a28bad57b01ab16bb903a9c84fa5421.1479844244.git.tim.c.chen@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/include/asm/topology.h
arch/x86/kernel/itmt.c