Re: [PATCH] powerpc/sched: Cleanup vcpu_is_preempted()
From: Srikar Dronamraju <hidden>
Date: 2023-11-14 09:47:30
* Aneesh Kumar K.V [off-list ref] [2023-11-14 12:42:19]:
quoted hunk ↗ jump to hunk
No functional change in this patch. A helper is added to find if vcpu is dispatched by hypervisor. Use that instead of opencoding. Also clarify some of the comments. Signed-off-by: Aneesh Kumar K.V <redacted> --- arch/powerpc/include/asm/paravirt.h | 33 ++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 8 deletions(-)diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h index ac4279208d63..b78b82d66057 100644 --- a/arch/powerpc/include/asm/paravirt.h +++ b/arch/powerpc/include/asm/paravirt.h@@ -76,6 +76,17 @@ static inline bool is_vcpu_idle(int vcpu) { return lppaca_of(vcpu).idle; } + +static inline bool vcpu_is_dispatched(int vcpu) +{ + /* + * This is the yield_count. An "odd" value (low bit on) means that + * the processor is yielded (either because of an OS yield or a + * hypervisor preempt). An even value implies that the processor is + * currently executing. + */ + return (!(yield_count_of(vcpu) & 1)); +} #else static inline bool is_shared_processor(void) {@@ -109,6 +120,10 @@ static inline bool is_vcpu_idle(int vcpu) { return false; } +static inline bool vcpu_is_dispatched(int vcpu) +{ + return true; +} #endif
If we are introducing vcpu_is_dispatched, we should remove yield_count_of() and use vcpu_is_dispatched everwhere No point in having yield_count_of() and vcpu_is_dispatched, since yield_count_of() is only used to check if we are running in OS or not. -- Thanks and Regards Srikar Dronamraju