Dear All,

 

This  patch is related to HMP force up migration, it will avoid sending of unnecessary interrupts to CPUs of faster domain hence increase performance.

 

 

 

[PATCH 1/1] HMP: Do not send IPI if core already waked up

 

HMP: Do not send IPI if core already waked up

 

It is possible that we are sending IPI to a cpu in faster domain which is

already waked up by other CPU in smaller domain.

 

HMP select the idle CPU using hmp_domain_min_load. Based on that HMP send IPI

to the idle cpu in faster domain. There could be some latency by the core to

wake up and set wake_for_idle_pull = 0. Next smaller cpu again check for

idle CPU in faster domain and send IPI to already waked up CPU.

 

For example: In Octacore system, 0-3 are slower CPUs and 4-7 are faster CPUs.

CPU0 and CPU1 has heavy tasks and CPU4 is idle.

CPU0 execute hmp_force_up_migration find CPU4 as idle, it send IPI to CPU4

and return. After that CPU1 got the chance to run hmp_force_up_migration,

it again find CPU4 as idle, send IPI to CPU4, which is not required.

 

Signed-off-by: rahulkhandelwal  <rahul.khandelwal@spreadtrum.com>