Re: [PATCH v3] ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512
From: Marek Szyprowski <m.szyprowski@samsung.com>
Date: 2024-03-11 16:51:09
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Hi Catalin, On 11.03.2024 16:22, Catalin Marinas wrote:
On Mon, Mar 11, 2024 at 03:56:37PM +0100, Marek Szyprowski wrote:quoted
On 11.03.2024 13:12, Mark Rutland wrote:quoted
On Fri, Mar 08, 2024 at 09:08:59AM -0800, Christoph Lameter (Ampere) wrote:quoted
On Fri, 8 Mar 2024, Marek Szyprowski wrote:quoted
quoted
quoted
It looks that cpufreq-dt and/or opp drivers needs some adjustments related with this change.That's strange. Is this with defconfig? I wonder whether NR_CPUS being larger caused the issue with this specific code. Otherwise CPUMASK_OFFSTACK may not work that well on arm64.cpumask handling must use the accessor functions provided in include/linux/cpumask.h for declaring and accessing cpumasks. It is likely related to the driver opencoding one of the accessors.I took a look at both the OPP code and the cpufreq-dt code and it looks like those are doign the right thing w.r.t. cpumask manipulation (i.e. they only use the cpumask accessors, and use the cpumask_var_*() functions to dynamically allocate/free cpumasks). Maybe I've missed something, but superficially those look right. Marek, can you try reverting this commit and trying defconfig + NR_CPUS=512?Yes, with $subject reverted and CONFIG_NR_CPUS=512 everything works fine, so it must be something else broken.Thanks for confirming. Would you mind testing the problematic commit with CONFIG_DEBUG_PER_CPU_MAPS enabled? If it doesn't show anything obvious that can be fixed quickly, I'll revert the commit and queue it again after -rc1 for 6.10 (I haven't sent 6.9 the pull request yet).
I've enabled this option, but unfortunately it didn't reveal anything more besides the warning and error I've posted in my initial report. I will try to analyze this issue further, but I won't manage to do this today. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel