2021-04-13 09:33:05

by Christian Borntraeger

Subject: Re: [PATCH v2 1/3] context_tracking: Split guest_enter/exit_irqoff

On 13.04.21 09:38, Wanpeng Li wrote:
> On Tue, 13 Apr 2021 at 15:35, Christian Borntraeger
> <[email protected]> wrote:
>>
>>
>>
>> On 13.04.21 09:16, Wanpeng Li wrote:
>> [...]
>>
>>> @@ -145,6 +155,13 @@ static __always_inline void guest_exit_irqoff(void)
>>> }
>>>
>>> #else
THis is the else part


>>> +static __always_inline void context_guest_enter_irqoff(void)
>>> +{
>>> + instrumentation_begin();

2nd on
>>> + rcu_virt_note_context_switch(smp_processor_id());
>>> + instrumentation_end();
2nd off
>>> +}
>>> +
>>> static __always_inline void guest_enter_irqoff(void)
>>> {
>>> /*
>>> @@ -155,10 +172,13 @@ static __always_inline void guest_enter_irqoff(void)
>>> instrumentation_begin();

first on
>>> vtime_account_kernel(current);
>>> current->flags |= PF_VCPU;
>>> - rcu_virt_note_context_switch(smp_processor_id());
>>> instrumentation_end();

first off
>>> +
>>> + context_guest_enter_irqoff();
here we call the 2nd on and off.
>>
>> So we now do instrumentation_begin 2 times?
>
> Similar to context_guest_enter_irqoff() ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN.

For the
ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN part
context_guest_enter_irqoff()
does not have instrumentation_begin/end.

Or did I miss anything.

2021-04-13 14:05:11

by Wanpeng Li

Subject: Re: [PATCH v2 1/3] context_tracking: Split guest_enter/exit_irqoff

On Tue, 13 Apr 2021 at 15:48, Christian Borntraeger
<[email protected]> wrote:
>
>
>
> On 13.04.21 09:38, Wanpeng Li wrote:
> > On Tue, 13 Apr 2021 at 15:35, Christian Borntraeger
> > <[email protected]> wrote:
> >>
> >>
> >>
> >> On 13.04.21 09:16, Wanpeng Li wrote:
> >> [...]
> >>
> >>> @@ -145,6 +155,13 @@ static __always_inline void guest_exit_irqoff(void)
> >>> }
> >>>
> >>> #else
> THis is the else part
>
>
> >>> +static __always_inline void context_guest_enter_irqoff(void)
> >>> +{
> >>> + instrumentation_begin();
>
> 2nd on
> >>> + rcu_virt_note_context_switch(smp_processor_id());
> >>> + instrumentation_end();
> 2nd off
> >>> +}
> >>> +
> >>> static __always_inline void guest_enter_irqoff(void)
> >>> {
> >>> /*
> >>> @@ -155,10 +172,13 @@ static __always_inline void guest_enter_irqoff(void)
> >>> instrumentation_begin();
>
> first on
> >>> vtime_account_kernel(current);
> >>> current->flags |= PF_VCPU;
> >>> - rcu_virt_note_context_switch(smp_processor_id());
> >>> instrumentation_end();
>
> first off
> >>> +
> >>> + context_guest_enter_irqoff();
> here we call the 2nd on and off.
> >>
> >> So we now do instrumentation_begin 2 times?
> >
> > Similar to context_guest_enter_irqoff() ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN.
>
> For the
> ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN part
> context_guest_enter_irqoff()
> does not have instrumentation_begin/end.
>
> Or did I miss anything.

I mean the if (!context_tracking_enabled_this_cpu()) part in the
function context_guest_enter_irqoff() ifdef
CONFIG_VIRT_CPU_ACCOUNTING_GEN. :)

Wanpeng