From: Xiongfeng Wang <wangxiongfeng2@huawei.com> hulk inclusion category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/9856 -------------------------------- Commit 08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full") allow CPU0 to be housekeeping CPU. But it is only supported when CONFIG_PM_SLEEP_SMP is not configured, or when it is configured and the arch allows suspend on non-zero CPUs. We cannot disable CONFIG_PM_SLEEP_SMP because freeze_secondary_cpus(), which is used in kexec, is included in the config. For arm64, there is no restriction in kernel to prevent nonzero cpu entering suspend using PSCI interface. when ARCH_SUSPEND_NONZERO_CPU is enabled, PM_SLEEP_SMP_NONZERO_CPU will be also enabled. The only influence is that suspend_disable_secondary_cpus() will use a housekeeping CPU to enter suspend. If pm sleep/hibernate is not involved, only kexec will use this function, which is tested on a arm64 server, and the vmcore can be created successfully. We add 'support_cpu0_nohz_full' in the CONFIG_PM_SLEEP_SMP_NONZERO_CPU check branch. When 'support_cpu0_nohz_full' is zero. There is no functional change. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: Xia Fukun <xiafukun@huawei.com> --- arch/arm64/Kconfig | 3 +++ include/linux/cpu.h | 3 ++- kernel/time/tick-sched.c | 2 +- 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 50146c8f8617..18080b5f0edf 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2871,6 +2871,9 @@ config ARCH_HIBERNATION_HEADER config ARCH_SUSPEND_POSSIBLE def_bool y +config ARCH_SUSPEND_NONZERO_CPU + def_bool y + config ARCH_CPUIDLE_HALTPOLL bool "Enable selection of the cpuidle-haltpoll driver" help diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 98e06cf4b49d..58b184e03016 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -20,6 +20,7 @@ #include <linux/cpuhotplug.h> #include <linux/cpuhplock.h> #include <linux/cpu_smt.h> +#include <linux/tick.h> struct device; struct device_node; @@ -143,7 +144,7 @@ static inline int suspend_disable_secondary_cpus(void) { int cpu = 0; - if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) + if (support_cpu0_nohz_full && IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) cpu = -1; return freeze_secondary_cpus(cpu); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 33a471692def..549160ecfd88 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -582,7 +582,7 @@ void __init tick_nohz_init(void) } if (IS_ENABLED(CONFIG_PM_SLEEP_SMP) && - !IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) { + (!support_cpu0_nohz_full || !IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))) { cpu = smp_processor_id(); if (cpumask_test_cpu(cpu, tick_nohz_full_mask)) { -- 2.34.1