Re: [PATCH v3] ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2024-03-18 18:17:28
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On Thu, Mar 07, 2024 at 07:07:07PM +0000, Catalin Marinas wrote:
On Wed, 06 Mar 2024 17:45:04 -0800, Christoph Lameter (Ampere) wrote:quoted
Currently defconfig selects NR_CPUS=256, but some vendors (e.g. Ampere Computing) are planning to ship systems with 512 CPUs. So that all CPUs on these systems can be used with defconfig, we'd like to bump NR_CPUS to 512. Therefore this patch increases the default NR_CPUS from 256 to 512. As increasing NR_CPUS will increase the size of cpumasks, there's a fear that this might have a significant impact on stack usage due to code which places cpumasks on the stack. To mitigate that concern, we can select CPUMASK_OFFSTACK. As that doesn't seem to be a problem today with NR_CPUS=256, we only select this when NR_CPUS > 256. [...]Applied to arm64 (for-next/misc), thanks! I dropped the config entry and comment, replaced it with a select as per Mark's suggestion. [1/1] ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512 https://git.kernel.org/arm64/c/0499a78369ad
I re-instated this patch in arm64 for-next/core as: https://git.kernel.org/arm64/c/3fbd56f0e7c1 -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel