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authorMark Brown <broonie@linaro.org>2014-04-06 19:45:48 +0100
committerAlex Shi <alex.shi@linaro.org>2014-06-04 16:02:54 +0800
commit5219b5d0caafb8f944df258eca8171b4dfa65eda (patch)
tree6677e45ab09f6173f35c826332ac757142f00af5
parent007c0a2f3f86aba4e143fd26338fa069caacc2cd (diff)
downloadlinux-linaro-stable-v3.14/topic/arm64-topology.tar.gz
arm64: topology: Provide relative power numbers for coresv3.14/topic/arm64-topology
Provide performance numbers to the scheduler to help it fill the cores in the system on big.LITTLE systems. With the current scheduler this may perform poorly for applications that try to do OpenMP style work over all cores but should help for more common workloads. The current 32 bit ARM implementation provides a similar estimate so this helps ensure that work to improve big.LITTLE systems on ARMv7 systems performs similarly on ARMv8 systems. The power numbers are the same as for ARMv7 since it seems that the expected differential between the big and little cores is very similar on both ARMv7 and ARMv8. In both ARMv7 and ARMv8 cases the numbers were based on the published DMIPS numbers. These numbers are just an initial and basic approximation for use with the current scheduler, it is likely that both experience with silicon and ongoing work on improving the scheduler will lead to further tuning or will tune automatically at runtime and so make the specific choice of numbers here less critical. Signed-off-by: Mark Brown <broonie@linaro.org> (cherry picked from LSK commit a84034fddb11f30849dd7ce050689d615995c0d2) Signed-off-by: Alex Shi <alex.shi@linaro.org>
-rw-r--r--arch/arm64/kernel/topology.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 540a939..d450a6d 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -200,6 +200,8 @@ struct cpu_efficiency {
* use the default SCHED_POWER_SCALE value for cpu_scale.
*/
static const struct cpu_efficiency table_efficiency[] = {
+ { "arm,cortex-a57", 3891 },
+ { "arm,cortex-a53", 2048 },
{ NULL, },
};