Study sched_mc for Arm

Registered by Vincent Guittot on 2011-04-19

Study kernel topology/scheduling domain and cpu group for Arm platform. We must validate that topology is SoC independent. Then define what should be a topology for Arm SoC ( Take into account dual/quad/.. cores and next cortex generation)
Study how irq balancing and timer migration can help.

wiki page:

Blueprint information

Amit Kucheria
Vincent Guittot
Vincent Guittot
Series goal:
Accepted for trunk
Milestone target:
milestone icon 2011.08
Started by
Amit Kucheria on 2011-06-03
Completed by
Mounir Bsaibes on 2011-09-20

Related branches



*Arm topology definition :
MIPDR register provides all thread/core/package info for Arm topology description
MPIDR register is accessed with MRC instruction
map MPIDR info on kernel topology

sched_mc uses topology description for creating sched_domain

*Timer and irq migration
available. need to check how/which pinned timer can impact power saving efficiency of sched_mc

Default sched_domain init can be overwritten by arch specific one. Study if we need to define some arm specific

Work Items for 2011.08
[vincent-guittot] study impact flags and fields of struct sched_domain in scheduling policy: DONE
[vincent-guittot] study the interest of adding some arm platform dedicated SD_XXX_INIT configuration: DONE

these items were moved to
[robertdavidlee] read MPIDR register on Freescale multi-core platforms: TODO
[vincent-guittot] study the interest of changing topology with sched_mc mode: TODO
[vincent-guittot] study the pinned timer impact on sched_mc power mode: TODO
[vincent-guittot] study the interest of using FDT for cpu topology definition: TODO


Work Items

Work items for 2011.07:
[vincent-guittot] read MPIDR register on ST-Ericsson platforms: DONE
[amitdanielk] read MPIDR register on Samsung platforms: DONE
[vishwanath-bs] read MPIDR register on omap4 platforms: DONE
[lorenzo-pieralisi] read MPIDR register on ELBA platforms: DONE
[vincent-guittot] consolidate MPIDR register results: DONE
[vincent-guittot] define scheduling topology for ARM: DONE
[vincent-guittot] add default topology definition for Arm platform: DONE
[vincent-guittot] test default topology definition for Arm platform: DONE

Dependency tree

* Blueprints in grey have been implemented.

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