Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 2 Mar 2020 23:31:13 -0500
From:   Rafael Aquini <aquini@redhat.com>
To:     Andrea Arcangeli <aarcange@redhat.com>
Cc:     Will Deacon <will@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Mark Salter <msalter@redhat.com>,
        Jon Masters <jcm@jonmasters.org>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
        Michal Hocko <mhocko@kernel.org>, QI Fuli <qi.fuli@fujitsu.com>
Subject: Re: [PATCH 2/3] arm64: select CPUMASK_OFFSTACK if NUMA
Message-ID: <20200303043113.GB94763@t490s>
References: <20200223192520.20808-1-aarcange@redhat.com>
 <20200223192520.20808-3-aarcange@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200223192520.20808-3-aarcange@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Sun, Feb 23, 2020 at 02:25:19PM -0500, Andrea Arcangeli wrote:
> It's unclear why normally CPUMASK_OFFSTACK can only be manually
> configured "if DEBUG_PER_CPU_MAPS" which is not an option meant to be
> enabled on enterprise arm64 kernels.
> 
> The default enterprise kernels NR_CPUS is 4096 which is fairly large.
> So it'll save some RAM and it'll increase reliability to select
> CPUMASK_OFFSET at least when NUMA is selected and a large NR_CPUS is
> to be expected.
> 
> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
> ---
>  arch/arm64/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 0b30e884e088..882887e65394 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -955,6 +955,7 @@ config NUMA
>  	bool "Numa Memory Allocation and Scheduler Support"
>  	select ACPI_NUMA if ACPI
>  	select OF_NUMA
> +	select CPUMASK_OFFSTACK
>  	help
>  	  Enable NUMA (Non Uniform Memory Access) support.
> 

Acked-by: Rafael Aquini <aquini@redhat.com>