On Thu, Oct 4, 2012 at 11:32 AM, Viresh Kumar viresh.kumar@linaro.org wrote:
Hi Morten,
On 22 September 2012 00:02, morten.rasmussen@arm.com wrote:
From: Morten Rasmussen morten.rasmussen@arm.com
This patch introduces the basic SCHED_HMP infrastructure. Each class of cpus is represented by a hmp_domain and tasks will only be moved between these domains when their load profiles suggest it is beneficial.
SCHED_HMP relies heavily on the task load-tracking introduced in Paul Turners fair group scheduling patch set:
https://lkml.org/lkml/2012/8/23/267
SCHED_HMP requires that the platform implements arch_get_hmp_domains() which should set up the platform specific list of hmp_domains. It is also assumed that the platform disables SD_LOAD_BALANCE for the appropriate sched_domains.
An explanation of this requirement would be helpful here.
Tasks placement takes place every time a task is to be inserted into a runqueue based on its load history. The task placement decision is based on load thresholds.
There are no restrictions on the number of hmp_domains, however, multiple (>2) has not been tested and the up/down migration policy is rather simple.
Signed-off-by: Morten Rasmussen morten.rasmussen@arm.com
arch/arm/Kconfig | 17 +++++ include/linux/sched.h | 6 ++ kernel/sched/fair.c | 168 +++++++++++++++++++++++++++++++++++++++++++++++++ kernel/sched/sched.h | 6 ++ 4 files changed, 197 insertions(+)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index f4a5d58..5b09684 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1554,6 +1554,23 @@ config SCHED_SMT MultiThreading at a cost of slightly increased overhead in some places. If unsure say N here.
+config DISABLE_CPU_SCHED_DOMAIN_BALANCE
bool "(EXPERIMENTAL) Disable CPU level scheduler load-balancing"helpDisables scheduler load-balancing at CPU sched domain level.Shouldn't this depend on EXPERIMENTAL?
EXPERIMENTAL might be on its way out: https://lkml.org/lkml/2012/10/2/398