linux-kernel - Re: [PATCH v4 1/5] powerpc/smp: Enable Asym packing for cores on shared processor

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Message-ID: <20231115113547.GV2194132@linux.vnet.ibm.com>
Date:   Wed, 15 Nov 2023 17:05:47 +0530
From:   Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
To:     "Aneesh Kumar K.V" <aneesh.kumar@...ux.ibm.com>
Cc:     Michael Ellerman <mpe@...erman.id.au>,
        Nicholas Piggin <npiggin@...il.com>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Mark Rutland <mark.rutland@....com>,
        Valentin Schneider <vschneid@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        "ndesaulniers@...gle.com" <ndesaulniers@...gle.com>,
        linux-kernel@...r.kernel.org, Rohan McLure <rmclure@...ux.ibm.com>,
        linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>,
        Josh Poimboeuf <jpoimboe@...nel.org>
Subject: Re: [PATCH v4 1/5] powerpc/smp: Enable Asym packing for cores on
 shared processor

* Aneesh Kumar K.V <aneesh.kumar@...ux.ibm.com> [2023-11-15 12:05:22]:

> Srikar Dronamraju <srikar@...ux.vnet.ibm.com> writes:
> 
> >
> >  arch/powerpc/kernel/smp.c | 37 +++++++++++++++++++++++++++++--------
> >  1 file changed, 29 insertions(+), 8 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
> > index ab691c89d787..69a3262024f1 100644
> > --- a/arch/powerpc/kernel/smp.c
> > +++ b/arch/powerpc/kernel/smp.c
> > @@ -993,16 +993,20 @@ static bool shared_caches;
> >  /* cpumask of CPUs with asymmetric SMT dependency */
> >  static int powerpc_smt_flags(void)
> >  {
> > -	int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
> > +	if (!cpu_has_feature(CPU_FTR_ASYM_SMT))
> > +		return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
> >  
> > -	if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
> > -		printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
> > -		flags |= SD_ASYM_PACKING;
> > -	}
> > -	return flags;
> > +	return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES | SD_ASYM_PACKING;
> >  }
> >  #endif
> >
> 
> Only relevant change there is dropping printk_once(). Rest of the
> changes are not needed?
> 
> -aneesh

If you are looking at just this hunk, then yes its moving the printk_once to
another function.

-- 
Thanks and Regards
Srikar Dronamraju