iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

powerpc/powernv/cpuidle: Init all present cpus for deep states

Browse Source 
commit ac9816dcbab53c57bcf1d7b15370b08f1e284318 upstream.

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@vger.kernel.org # v3.19+
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Akshay Adiga 2018-05-16 17:32:14 +05:30 committed by Greg Kroah-Hartman
parent 134e70c22e
commit a5d49dfb20
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/powerpc/platforms/powernv/idle.c
View File

@ -78,7 +78,7 @@ 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[cpu];
@ -741,7 +741,7 @@ 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;