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Mon, 20 Jul 2020 08:52:21 +0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06K8qGLk20382182 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 20 Jul 2020 08:52:16 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8F46AAE051; Mon, 20 Jul 2020 08:52:16 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A6E38AE053; Mon, 20 Jul 2020 08:52:14 +0000 (GMT) Received: from linux.vnet.ibm.com (unknown [9.126.150.29]) by d06av26.portsmouth.uk.ibm.com (Postfix) with SMTP; Mon, 20 Jul 2020 08:52:14 +0000 (GMT) Date: Mon, 20 Jul 2020 14:22:14 +0530 From: Srikar Dronamraju To: Jordan Niethe Subject: Re: [PATCH 04/11] powerpc/smp: Enable small core scheduling sooner Message-ID: <20200720085214.GG21103@linux.vnet.ibm.com> References: <20200714043624.5648-1-srikar@linux.vnet.ibm.com> <20200714043624.5648-5-srikar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-20_04:2020-07-17, 2020-07-20 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 malwarescore=0 clxscore=1015 adultscore=0 bulkscore=0 impostorscore=0 mlxscore=0 phishscore=0 priorityscore=1501 suspectscore=0 spamscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007200060 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Srikar Dronamraju Cc: Nathan Lynch , Gautham R Shenoy , Oliver OHalloran , Michael Neuling , Michael Ellerman , Anton Blanchard , linuxppc-dev , Nick Piggin Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" * Jordan Niethe [2020-07-20 17:47:27]: > On Tue, Jul 14, 2020 at 2:44 PM Srikar Dronamraju > wrote: > > > > Enable small core scheduling as soon as we detect that we are in a > > system that supports thread group. Doing so would avoid a redundant > > check. > > > > Cc: linuxppc-dev > > Cc: Michael Ellerman > > Cc: Nick Piggin > > Cc: Oliver OHalloran > > Cc: Nathan Lynch > > Cc: Michael Neuling > > Cc: Anton Blanchard > > Cc: Gautham R Shenoy > > Cc: Vaidyanathan Srinivasan > > Signed-off-by: Srikar Dronamraju > > --- > > arch/powerpc/kernel/smp.c | 12 ++++++------ > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c > > index 24529f6134aa..7d430fc536cc 100644 > > --- a/arch/powerpc/kernel/smp.c > > +++ b/arch/powerpc/kernel/smp.c > > @@ -892,6 +892,12 @@ static int init_big_cores(void) > > } > > > > has_big_cores = true; > > + > > +#ifdef CONFIG_SCHED_SMT > > + pr_info("Big cores detected. Using small core scheduling\n"); > Why change the wording from "Big cores detected but using small core > scheduling\n"? > > + powerpc_topology[0].mask = smallcore_smt_mask; > > +#endif > > + To me, "but" in the message sounded as if we detected Big cores *but* we want to continue using smallcore scheduling. However the code was always meaning to say, "Since we detected big core, i.e thread grouping within a core, System would benefit by using small core scheduling". If you think, "but" was adding more info and not misleading, then I can add it back. > > return 0; > > } > > -- Thanks and Regards Srikar Dronamraju