From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Akshay Adiga , Michael Ellerman Subject: [PATCH 4.14 040/157] powerpc/powernv/cpuidle: Init all present cpus for deep states Date: Sun, 1 Jul 2018 18:21:52 +0200 Message-Id: <20180701160854.470397930@linuxfoundation.org> In-Reply-To: <20180701160852.287307684@linuxfoundation.org> References: <20180701160852.287307684@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Akshay Adiga 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 Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/powernv/idle.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -78,7 +78,7 @@ static int pnv_save_sprs_for_deep_states 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(v 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;