Subject: Re: [RFC PATCH 06/12] [WIP] powerpc/tm: Remove dead code from __switch_to_tm()

From: Cyril Bur <[email-masked]>
Date: Tue, 20 Feb 2018 14:43:45 +1100

On Tue, 2018-02-20 at 13:52 +1100, Michael Neuling wrote:
> Not sure I understand this.. should it be merged with the last patch?
> 

Its all going to have to be one patch - I've left it split out to make
it more obvious which bits have had to mess with, this series
absolutely doesn't bisect.

> Needs a comment here.
> 
> 
> On Tue, 2018-02-20 at 11:22 +1100, Cyril Bur wrote:
> > ---
> >  arch/powerpc/kernel/process.c | 24 +++++-------------------
> >  1 file changed, 5 insertions(+), 19 deletions(-)
> > 
> > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> > index ea75da0fd506..574b05fe7d66 100644
> > --- a/arch/powerpc/kernel/process.c
> > +++ b/arch/powerpc/kernel/process.c
> > @@ -1027,27 +1027,13 @@ static inline void __switch_to_tm(struct task_struct *prev,
> >  		struct task_struct *new)
> >  {
> >  	/*
> > -	 * So, with the rework none of this code should not be needed.
> > -	 * I've left in the reclaim for now. This *should* save us
> > -	 * from any mistake in the new code. Also the
> > -	 * enabling/disabling logic of MSR_TM really should be
> > +	 * The enabling/disabling logic of MSR_TM really should be
> >  	 * refactored into a common way with MSR_{FP,VEC,VSX}
> >  	 */
> > -	if (cpu_has_feature(CPU_FTR_TM)) {
> > -		if (tm_enabled(prev) || tm_enabled(new))
> > -			tm_enable();
> > -
> > -		if (tm_enabled(prev)) {
> > -			prev->thread.load_tm++;
> > -			tm_reclaim_task(prev);
> > -			/*
> > -			 * The disabling logic may be confused don't
> > -			 * disable for now
> > -			 *
> > -			 * if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0)
> > -			 *	prev->thread.regs->msr &= ~MSR_TM;
> > -			 */
> > -		}
> > +	if (cpu_has_feature(CPU_FTR_TM) && tm_enabled(prev)) {
> > +		prev->thread.load_tm++;
> > +		if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0)
> > +			prev->thread.regs->msr &= ~MSR_TM;
> >  	}
> >  }
> >