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Re: [Qemu-devel] [PATCH v3 8/8] target-i386/kvm: cache the return value
From: |
Igor Mammedov |
Subject: |
Re: [Qemu-devel] [PATCH v3 8/8] target-i386/kvm: cache the return value of kvm_enable_x2apic() |
Date: |
Tue, 4 Oct 2016 13:33:15 +0200 |
On Fri, 30 Sep 2016 18:10:13 +0200
Radim Krčmář <address@hidden> wrote:
> Assume that KVM would have returned the same on subsequent runs.
> Abstract the memoizaiton pattern into macros.
s/memoi/memori/i
Throughout whole patch
>
> Signed-off-by: Radim Krčmář <address@hidden>
> ---
> target-i386/kvm.c | 21 +++++++++++++++++++--
> 1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/target-i386/kvm.c b/target-i386/kvm.c
> index 0fd664648665..113c5bf058ba 100644
> --- a/target-i386/kvm.c
> +++ b/target-i386/kvm.c
> @@ -129,10 +129,27 @@ static bool kvm_x2apic_api_set_flags(uint64_t flags)
> return !kvm_vm_enable_cap(s, KVM_CAP_X2APIC_API, 0, flags);
> }
>
> +#define MEMOIZE_RESULT(_result, _fn) \
> + ({ \
> + static bool _memoized; \
> + if (_memoized) { \
> + return _result; \
> + } \
> + _memoized = true; \
> + _result = _fn; \
> + })
> +
> +#define MEMOIZE(_fn) \
> + ({ \
> + static typeof(_fn) _result; \
> + MEMOIZE_RESULT(_result, _fn); \
> + })
> +
> bool kvm_enable_x2apic(void)
> {
> - return kvm_x2apic_api_set_flags(KVM_X2APIC_API_USE_32BIT_IDS |
> - KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK);
> + return MEMOIZE(
> + kvm_x2apic_api_set_flags(KVM_X2APIC_API_USE_32BIT_IDS |
> +
> KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK));
> }
>
> static int kvm_get_tsc(CPUState *cs)
- Re: [Qemu-devel] [PATCH v3 8/8] target-i386/kvm: cache the return value of kvm_enable_x2apic(),
Igor Mammedov <=