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Subject: Re: [PATCH v4 1/2] powerpc/time: Only set
 CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC64
To:     Nicholas Piggin <npiggin@gmail.com>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        Segher Boessenkool <segher@kernel.crashing.org>
References: <d9ac8da98f53debb4758b98d0227979aca9196f7.1528292284.git.christophe.leroy@c-s.fr>
 <20180607114304.327c4ab5@roar.ozlabs.ibm.com>
From:   Christophe Leroy <christophe.leroy@c-s.fr>
Message-ID: <26969bb5-c01b-0674-5773-027f1851bd44@c-s.fr>
Date:   Wed, 14 Aug 2019 08:31:02 +0200
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Hi Nick,


Le 07/06/2018 à 03:43, Nicholas Piggin a écrit :
> On Wed,  6 Jun 2018 14:21:08 +0000 (UTC)
> Christophe Leroy <christophe.leroy@c-s.fr> wrote:
> 
>> scaled cputime is only meaningfull when the processor has
>> SPURR and/or PURR, which means only on PPC64.
>>

[...]

> 
> I wonder if we could make this depend on PPC_PSERIES or even
> PPC_SPLPAR as well? (That would be for a later patch)

Can we go further on this ?

Do we know exactly which configuration support scaled cputime, in 
extenso have SPRN_SPURR and/or SPRN_PURR ?

Ref https://github.com/linuxppc/issues/issues/171

Christophe