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Peter Anvin" , Jonathan Cameron , Juri Lelli , "Cc: Len Brown" , ACPI Devel Maling List , LAK , Linuxarm , Mark Rutland , Mel Gorman , msys.mizuma@gmail.com, "Zengtao (B)" , "Rafael J. Wysocki" , Steven Rostedt , Barry Song , Sudeep Holla , Thomas Gleixner , "Rafael J. Wysocki" , Valentin Schneider , Will Deacon , x86 , yangyicong Subject: Re: [PATCH RESEND 0/3] Represent cluster topology and enable load balance between clusters Message-ID: <20211005080413.GL4323@worktop.programming.kicks-ass.net> References: <20210924085104.44806-1-21cnbao@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Oct 02, 2021 at 08:09:58PM +1300, Barry Song wrote: > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 7e4651a1aaf4..86821e83b935 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -993,8 +993,13 @@ config SCHED_CLUSTER > bool "Cluster scheduler support" > help > Cluster scheduler support improves the CPU scheduler's decision > + making when dealing with machines that have clusters of CPUs. > + Cluster usually means a couple of CPUs which are placed closely > + by sharing mid-level caches, last-level cache tags or internal > + busses. For example, on Hisilicon Kunpeng920, each 4 CPUs share > + LLC cache tags. This feature isn't a universal win because it > + can bring a cost of slightly increased overhead in some places. > + If unsure say N here. > > config SCHED_SMT > bool "SMT scheduler support" > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index bd27b1cdac34..940eb1fe0abb 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -1002,12 +1002,17 @@ config NR_CPUS > to the kernel image. > > config SCHED_CLUSTER > + def_bool y > + prompt "Cluster scheduler support" > help > Cluster scheduler support improves the CPU scheduler's decision > + making when dealing with machines that have clusters of CPUs. > + Cluster usually means a couple of CPUs which are placed closely > + by sharing mid-level caches, last-level cache tags or internal > + busses. For example, on x86 Jacobsville, each 4 CPUs share one > + L2 cache. This feature isn't a universal win because it can bring > + a cost of slightly increased overhead in some places. If unsure > + say N here. That is a really odd addition to a default-y feature. How about I make both: help Cluster scheduler support improves the CPU scheduler's decision making when dealing with machines that have clusters of CPUs. Cluster usually means a couple of CPUs which are placed closely by sharing mid-level caches, last-level cache tags or internal busses. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel