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From: Michael Ellerman <mpe@ellerman.id.au>
To: Paul Mackerras <paulus@ozlabs.org>, Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org
Subject: Re: [PATCH v3 2/4] powerpc/64s: idle POWER9 can execute stop without a sync sequence
Date: Tue, 29 Aug 2017 20:30:37 +1000	[thread overview]
Message-ID: <87mv6i1x9u.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20170829001110.GD12629@fergus.ozlabs.ibm.com>

Paul Mackerras <paulus@ozlabs.org> writes:
> On Fri, Aug 25, 2017 at 02:30:34PM +1000, Nicholas Piggin wrote:
>> diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
>> index 4924647d964d..14e97f442167 100644
>> --- a/arch/powerpc/kernel/idle_book3s.S
>> +++ b/arch/powerpc/kernel/idle_book3s.S
>> @@ -205,6 +205,19 @@ pnv_powersave_common:
>>  	mtmsrd	r7,0
>>  	bctr
>>  
>> +/*
>> + * This is the sequence required to execute idle instructions, as
>> + * specified in ISA v2.07. MSR[IR] and MSR[DR] must be 0.
>> + */
>> +#define ARCH207_IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST)		\
>
> We had to do this sequence on POWER7 also, which is architecture
> v2.06.  Thus the comments and the naming (ARCH207_*) are a bit
> misleading here.  The actual code change looks OK.

I'll just drop the name change, I don't think it's crucial. That makes
P9 the special case.

We can come up with a better name or something in future.

Unless Nick objects?

cheers

WARNING: multiple messages have this Message-ID (diff)
From: Michael Ellerman <mpe@ellerman.id.au>
To: Paul Mackerras <paulus@ozlabs.org>, Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org
Subject: Re: [PATCH v3 2/4] powerpc/64s: idle POWER9 can execute stop without a sync sequence
Date: Tue, 29 Aug 2017 10:30:37 +0000	[thread overview]
Message-ID: <87mv6i1x9u.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <20170829001110.GD12629@fergus.ozlabs.ibm.com>

Paul Mackerras <paulus@ozlabs.org> writes:
> On Fri, Aug 25, 2017 at 02:30:34PM +1000, Nicholas Piggin wrote:
>> diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
>> index 4924647d964d..14e97f442167 100644
>> --- a/arch/powerpc/kernel/idle_book3s.S
>> +++ b/arch/powerpc/kernel/idle_book3s.S
>> @@ -205,6 +205,19 @@ pnv_powersave_common:
>>  	mtmsrd	r7,0
>>  	bctr
>>  
>> +/*
>> + * This is the sequence required to execute idle instructions, as
>> + * specified in ISA v2.07. MSR[IR] and MSR[DR] must be 0.
>> + */
>> +#define ARCH207_IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST)		\
>
> We had to do this sequence on POWER7 also, which is architecture
> v2.06.  Thus the comments and the naming (ARCH207_*) are a bit
> misleading here.  The actual code change looks OK.

I'll just drop the name change, I don't think it's crucial. That makes
P9 the special case.

We can come up with a better name or something in future.

Unless Nick objects?

cheers

  reply	other threads:[~2017-08-29 10:31 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-25  4:30 [PATCH v3 0/4] powerpc/64s: idle POWER9 stop improvements Nicholas Piggin
2017-08-25  4:30 ` Nicholas Piggin
2017-08-25  4:30 ` [PATCH v3 1/4] KVM: PPC: Book3S HV: POWER9 does not require secondary thread management Nicholas Piggin
2017-08-25  4:30   ` Nicholas Piggin
2017-08-28 11:49   ` Michael Ellerman
2017-08-28 11:49     ` Michael Ellerman
2017-08-29  0:13   ` Paul Mackerras
2017-08-29  0:13     ` Paul Mackerras
2017-08-31 11:36   ` [v3, " Michael Ellerman
2017-08-31 11:36     ` Michael Ellerman
2017-08-25  4:30 ` [PATCH v3 2/4] powerpc/64s: idle POWER9 can execute stop without a sync sequence Nicholas Piggin
2017-08-25  4:30   ` Nicholas Piggin
2017-08-29  0:11   ` Paul Mackerras
2017-08-29  0:11     ` Paul Mackerras
2017-08-29 10:30     ` Michael Ellerman [this message]
2017-08-29 10:30       ` Michael Ellerman
2017-08-31 11:36   ` [v3, " Michael Ellerman
2017-08-31 11:36     ` Michael Ellerman
2017-08-25  4:30 ` [PATCH v3 3/4] powerpc/64s: idle POWER9 can execute stop in virtual mode Nicholas Piggin
2017-08-25  4:30   ` Nicholas Piggin
2017-08-29  0:14   ` Paul Mackerras
2017-08-29  0:14     ` Paul Mackerras
2017-08-31 11:36   ` [v3, " Michael Ellerman
2017-08-31 11:36     ` [v3,3/4] " Michael Ellerman
2017-08-25  4:30 ` [PATCH v3 4/4] powerpc/64s: idle ESL=0 stop can avoid MSR and save/restore overhead Nicholas Piggin
2017-08-25  4:30   ` Nicholas Piggin
2017-08-29  0:20   ` Paul Mackerras
2017-08-29  0:20     ` Paul Mackerras
2017-08-29  1:39     ` Nicholas Piggin
2017-08-29  1:39       ` Nicholas Piggin
2017-08-30 11:25   ` Michael Ellerman
2017-08-30 11:25     ` Michael Ellerman
2017-08-30 12:10     ` Nicholas Piggin
2017-08-30 12:10       ` Nicholas Piggin
2017-09-01  9:39       ` Michael Ellerman
2017-09-01  9:39         ` Michael Ellerman
2017-09-20 13:56         ` Nicholas Piggin
2017-09-20 13:56           ` Nicholas Piggin

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