Re: [PATCH 4/7] static_key: use static_key_slow_inc_deferred()

From: Paolo Bonzini
Date: Thu Oct 17 2013 - 06:39:19 EST


Il 17/10/2013 12:10, Radim KrÄmÃÅ ha scritto:
> Simple replacement where possible.
> Saves us problematic access to the structure and allows optimalizations
> and bug fixes to take place.

I think you should introduce this first as a simple wrapper around
static_key_slow_inc, and then add the bells and whistles you have in
patches 2 and 3.

Paolo

> Signed-off-by: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
> ---
> arch/x86/kvm/lapic.c | 7 ++++---
> kernel/events/core.c | 6 +++---
> 2 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 5439117..eff85f6 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -121,7 +121,7 @@ static inline void apic_set_spiv(struct kvm_lapic *apic, u32 val)
> if (val & APIC_SPIV_APIC_ENABLED)
> static_key_slow_dec_deferred(&apic_sw_disabled);
> else
> - static_key_slow_inc(&apic_sw_disabled.key);
> + static_key_slow_inc_deferred(&apic_sw_disabled);
> }
> apic_set_reg(apic, APIC_SPIV, val);
> }
> @@ -1351,7 +1351,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
> if (value & MSR_IA32_APICBASE_ENABLE)
> static_key_slow_dec_deferred(&apic_hw_disabled);
> else
> - static_key_slow_inc(&apic_hw_disabled.key);
> + static_key_slow_inc_deferred(&apic_hw_disabled);
> recalculate_apic_map(vcpu->kvm);
> }
>
> @@ -1546,7 +1546,8 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu)
> kvm_lapic_set_base(vcpu,
> APIC_DEFAULT_PHYS_BASE | MSR_IA32_APICBASE_ENABLE);
>
> - static_key_slow_inc(&apic_sw_disabled.key); /* sw disabled at reset */
> + /* sw disabled at reset */
> + static_key_slow_inc_deferred(&apic_sw_disabled);
> kvm_lapic_reset(vcpu);
> kvm_iodevice_init(&apic->dev, &apic_mmio_ops);
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index d49a9d2..ade89a1 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -6565,7 +6565,7 @@ static void account_event(struct perf_event *event)
> return;
>
> if (event->attach_state & PERF_ATTACH_TASK)
> - static_key_slow_inc(&perf_sched_events.key);
> + static_key_slow_inc_deferred(&perf_sched_events);
> if (event->attr.mmap || event->attr.mmap_data)
> atomic_inc(&nr_mmap_events);
> if (event->attr.comm)
> @@ -6577,9 +6577,9 @@ static void account_event(struct perf_event *event)
> tick_nohz_full_kick_all();
> }
> if (has_branch_stack(event))
> - static_key_slow_inc(&perf_sched_events.key);
> + static_key_slow_inc_deferred(&perf_sched_events);
> if (is_cgroup_event(event))
> - static_key_slow_inc(&perf_sched_events.key);
> + static_key_slow_inc_deferred(&perf_sched_events);
>
> account_event_cpu(event, event->cpu);
> }
>

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