Messages in this thread | | | From | Jürgen Groß <> | Subject | Re: [PATCH v6 02/12] x86/paravirt: switch time pvops functions to use static_call() | Date | Wed, 10 Mar 2021 08:51:22 +0100 |
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On 09.03.21 19:57, Borislav Petkov wrote: > On Tue, Mar 09, 2021 at 02:48:03PM +0100, Juergen Gross wrote: >> @@ -167,6 +168,17 @@ static u64 native_steal_clock(int cpu) >> return 0; >> } >> >> +DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock); >> +DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock); >> + >> +bool paravirt_using_native_sched_clock = true; >> + >> +void paravirt_set_sched_clock(u64 (*func)(void)) >> +{ >> + static_call_update(pv_sched_clock, func); >> + paravirt_using_native_sched_clock = (func == native_sched_clock); >> +} > > What's the point of this function if there's a global > paravirt_using_native_sched_clock variable now?
It is combining the two needed actions: update the static call and set the paravirt_using_native_sched_clock boolean.
> Looking how the bit of information whether native_sched_clock is used, > is needed in tsc.c, it probably would be cleaner if you add a > > set_sched_clock_native(void); > > or so, to tsc.c instead and call that here and make that long var name a > a shorter and static one in tsc.c instead.
I need to transfer a boolean value, so it would need to be
set_sched_clock_native(bool state);
In the end the difference is only marginal IMO.
Just had another idea: I could add a function to static_call.h for querying the current function. This would avoid the double book keeping and could probably be used later when switching other pv_ops calls to static_call, too (e.g. pv_is_native_spin_unlock()).
What do you think?
Juergen [unhandled content-type:application/pgp-keys][unhandled content-type:application/pgp-signature] | |