[RFC] sched/fair: Penalty the cfs task which executes mwait/hlt

Message ID	1578448201-28218-1-git-send-email-wanpengli@tencent.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=A2Rt=25=vger.kernel.org=kvm-owner@kernel.org> From: Wanpeng Li <kernellwp@gmail.com> To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Marcelo Tosatti <mtosatti@redhat.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, KarimAllah <karahmed@amazon.de>, Vincent Guittot <vincent.guittot@linaro.org>, Ingo Molnar <mingo@kernel.org>, Ankur Arora <ankur.a.arora@oracle.com> Subject: [PATCH RFC] sched/fair: Penalty the cfs task which executes mwait/hlt Date: Wed, 8 Jan 2020 09:50:01 +0800 Message-Id: <1578448201-28218-1-git-send-email-wanpengli@tencent.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk
Series	[RFC] sched/fair: Penalty the cfs task which executes mwait/hlt \| expand [RFC] sched/fair: Penalty the cfs task which executes mwait/hlt

diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index e15f364..61e5b9b 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -28,6 +28,7 @@ DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map); DECLARE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id); DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number); +DECLARE_PER_CPU(bool, cpu_is_idle); static inline struct cpumask *cpu_llc_shared_mask(int cpu) { diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h index 4b14d23..13e2ffc 100644 --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -193,4 +193,11 @@ static inline void sched_clear_itmt_support(void) } #endif /* CONFIG_SCHED_MC_PRIO */ +#ifdef CONFIG_SMP +#include <asm/cpufeature.h> + +#define arch_scale_freq_tick arch_scale_freq_tick +extern void arch_scale_freq_tick(void); +#endif + #endif /* _ASM_X86_TOPOLOGY_H */ diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 69881b2..390534e 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -99,6 +99,9 @@ DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); +DEFINE_PER_CPU(bool, cpu_is_idle); +EXPORT_PER_CPU_SYMBOL(cpu_is_idle); + /* Logical package management. We might want to allocate that dynamically */ unsigned int __max_logical_packages __read_mostly; EXPORT_SYMBOL(__max_logical_packages); @@ -147,6 +150,8 @@ static inline void smpboot_restore_warm_reset_vector(void) *((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0; } +static void set_cpu_sample(void); + /* * Report back to the Boot Processor during boot time or to the caller processor * during CPU online. @@ -183,6 +188,8 @@ static void smp_callin(void) */ set_cpu_sibling_map(raw_smp_processor_id()); + set_cpu_sample(); + /* * Get our bogomips. * Update loops_per_jiffy in cpu_data. Previous call to @@ -1337,7 +1344,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus) set_sched_topology(x86_topology); set_cpu_sibling_map(0); - + set_cpu_sample(); smp_sanity_check(); switch (apic_intr_mode) { @@ -1764,3 +1771,47 @@ void native_play_dead(void) } #endif + +static DEFINE_PER_CPU(u64, arch_prev_tsc); +static DEFINE_PER_CPU(u64, arch_prev_mperf); + +#include <asm/cpu_device_id.h> +#include <asm/intel-family.h> + +#define ICPU(model) \ + { X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF, 0} + +static void set_cpu_sample(void) +{ + u64 mperf; + + if (!boot_cpu_has(X86_FEATURE_APERFMPERF)) + return; + + rdmsrl(MSR_IA32_MPERF, mperf); + + this_cpu_write(arch_prev_tsc, rdtsc()); + this_cpu_write(arch_prev_mperf, mperf); + this_cpu_write(cpu_is_idle, true); +} + +void arch_scale_freq_tick(void) +{ + u64 mperf; + u64 mcnt, tsc; + int result; + + if (!static_cpu_has(X86_FEATURE_APERFMPERF)) + return; + + rdmsrl(MSR_IA32_MPERF, mperf); + + mcnt = mperf - this_cpu_read(arch_prev_mperf); + tsc = rdtsc() - this_cpu_read(arch_prev_tsc); + if (!mcnt) + return; + + this_cpu_write(arch_prev_tsc, rdtsc()); + this_cpu_write(arch_prev_mperf, mperf); + this_cpu_write(cpu_is_idle, (mcnt * 100 / tsc) == 0); +} diff --git a/kernel/sched/core.c b/kernel/sched/core.c index dd05a37..e41ad01 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3593,6 +3593,7 @@ void scheduler_tick(void) struct task_struct *curr = rq->curr; struct rq_flags rf; + arch_scale_freq_tick(); sched_clock_tick(); rq_lock(rq, &rf); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 83ab35e..5ff7431 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4118,10 +4118,18 @@ static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se) unsigned long ideal_runtime, delta_exec; struct sched_entity *se; s64 delta; + bool resched = false; ideal_runtime = sched_slice(cfs_rq, curr); delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; - if (delta_exec > ideal_runtime) { + + if (sched_feat(IDLE_PENALTY) && this_cpu_read(cpu_is_idle) && + (ideal_runtime > delta_exec)) { + curr->vruntime += calc_delta_fair(ideal_runtime - delta_exec, curr); + update_min_vruntime(cfs_rq); + resched = true; + } + if (delta_exec > ideal_runtime || resched) { resched_curr(rq_of(cfs_rq)); /* * The current task ran long enough, ensure it doesn't get diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 2410db5..bacf59d 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -13,6 +13,11 @@ SCHED_FEAT(START_DEBIT, true) /* + * Penalty the cfs task which executes mwait/hlt + */ +SCHED_FEAT(IDLE_PENALTY, true) + +/* * Prefer to schedule the task we woke last (assuming it failed * wakeup-preemption), since its likely going to consume data we * touched, increases cache locality. diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 0db2c1b..0fe4f2d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1953,6 +1953,13 @@ static inline int hrtick_enabled(struct rq *rq) #endif /* CONFIG_SCHED_HRTICK */ +#ifndef arch_scale_freq_tick +static __always_inline +void arch_scale_freq_tick(void) +{ +} +#endif + #ifndef arch_scale_freq_capacity static __always_inline unsigned long arch_scale_freq_capacity(int cpu)

[RFC] sched/fair: Penalty the cfs task which executes mwait/hlt

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