Re: [PATCH 4/7] x86/intel_rdt: Implement scheduling support for Intel RDT

[Vikas Shivappa]

On Fri, 8 May 2015, Peter Zijlstra wrote:

> On Thu, May 07, 2015 at 04:15:41PM -0700, Vikas Shivappa wrote:
> > > No.
> > >
> > > 1) two arch hooks right after one another is FAIL
> > > 1a) just 'fix' the existing hook
> > > 2) current is cheap and easily obtainable without passing it as
> > >   an argument
> >
> > will fix to just use an existing hook in finish_task_switch and
> > current(get_current) since the stack would already be changed ..
> >
> > Thanks,
> > Vikas
> >
> > > 3) why do you need the hook in the first place?
> > > 3a) why can't you put this in __switch_to()? This is very much x86 only
> > >    code.
>
> ^ please also answer 3, why can't this go in __swtich_to()?

perf uses similar(#1a) hook to update its MSRs (including for cache 
monitoring ).
Also since switch_to is for registers state and stack , may be a 
safer option to use it in the finish_arch_switch? Thats kind of why we had it 
there at first but had a seperate hook.

#define finish_arch_switch(prev)					\
do {									\
	intel_rdt_sched_in();						\
} while (0)


Hpa , any comments ?

>
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