The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From ac9816dcbab53c57bcf1d7b15370b08f1e284318 Mon Sep 17 00:00:00 2001
From: Akshay Adiga <akshay.adiga@xxxxxxxxxxxxxxxxxx>
Date: Wed, 16 May 2018 17:32:14 +0530
Subject: [PATCH] powerpc/powernv/cpuidle: Init all present cpus for deep
states
Init all present cpus for deep states instead of "all possible" cpus.
Init fails if a possible cpu is guarded. Resulting in making only
non-deep states available for cpuidle/hotplug.
Stewart says, this means that for single threaded workloads, if you
guard out a CPU core you'll not get WoF (Workload Optimised
Frequency), which means that performance goes down when you wouldn't
expect it to.
Fixes: 77b54e9f213f ("powernv/powerpc: Add winkle support for offline cpus")
Cc: stable@xxxxxxxxxxxxxxx # v3.19+
Signed-off-by: Akshay Adiga <akshay.adiga@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 1f12ab1e6030..1c5d0675b43c 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -79,7 +79,7 @@ static int pnv_save_sprs_for_deep_states(void)
uint64_t msr_val = MSR_IDLE;
uint64_t psscr_val = pnv_deepest_stop_psscr_val;
- for_each_possible_cpu(cpu) {
+ for_each_present_cpu(cpu) {
uint64_t pir = get_hard_smp_processor_id(cpu);
uint64_t hsprg0_val = (uint64_t)paca_ptrs[cpu];
@@ -814,7 +814,7 @@ static int __init pnv_init_idle_states(void)
int cpu;
pr_info("powernv: idle: Saving PACA pointers of all CPUs in their thread sibling PACA\n");
- for_each_possible_cpu(cpu) {
+ for_each_present_cpu(cpu) {
int base_cpu = cpu_first_thread_sibling(cpu);
int idx = cpu_thread_in_core(cpu);
int i;
