Re: [PATCH v4 1/2] powerpc/vcpu: Assume dedicated processors as non-preempt

2019-12-12 Thread Michael Ellerman
Srikar Dronamraju writes: > With commit 247f2f6f3c70 ("sched/core: Don't schedule threads on pre-empted > vCPUs"), scheduler avoids preempted vCPUs to schedule tasks on wakeup. > This leads to wrong choice of CPU, which in-turn leads to larger wakeup > latencies. Eventually, it leads to

[PATCH v4 1/2] powerpc/vcpu: Assume dedicated processors as non-preempt

2019-12-12 Thread Srikar Dronamraju
With commit 247f2f6f3c70 ("sched/core: Don't schedule threads on pre-empted vCPUs"), scheduler avoids preempted vCPUs to schedule tasks on wakeup. This leads to wrong choice of CPU, which in-turn leads to larger wakeup latencies. Eventually, it leads to performance regression in latency sensitive