Error while enabling CMA on ubuntu 20.04 kernel (5.15.0-52-generic)

lorenc

10/30/23, 4:26 PM

My PC has ubuntu 20.04 running kernel (5.15.0-52-generic). I got the source for my kernel and then tried to enable CMA (Contiguous Memory Management). running the following command: $ LANG=C fakeroot debian/rules editconfigs fails some checks with the following warnings:

check-config: /tmp/tmp.okfgV2ZLKk/CONFIGS/amd64-config.flavour.lowlatency: loading config check-config: /home/tester/linux/linux-hwe-5.15-5.15.0/debian.hwe-5.15/config/annotations loading annotations check-config: FAIL (n != -): CONFIG_DMA_PERNUMA_CMA policy<{'arm64': 'y', 'armhf': 'n'}> check-config: FAIL (32 != -): CONFIG_CMA_SIZE_MBYTES policy<{'arm64': '32', 'armhf': '32'}> mark note<LP:1823753> check-config: FAIL (n != -): CONFIG_CMA_SIZE_SEL_PERCENTAGE policy<{'arm64': 'n', 'armhf': 'n'}> check-config: FAIL (y != -): CONFIG_CMA_SYSFS policy<{'arm64': 'y', 'armhf': 'y', 'ppc64el': 'y', 's390x': 'y'}> check-config: FAIL (8 != -): CONFIG_CMA_ALIGNMENT policy<{'arm64': '8', 'armhf': '8'}> check-config: FAIL (y != -): CONFIG_CMA_SIZE_SEL_MBYTES policy<{'arm64': 'y', 'armhf': 'y'}> check-config: FAIL (y != -): CONFIG_DMA_CMA policy<{'arm64': 'y', 'armhf': 'y', 's390x': 'n'}> mark note<LP#1362261> note<LP:1803206> check-config: FAIL (y != -): CONFIG_CMA_DEBUGFS policy<{'arm64': 'n', 'armhf': 'n', 'ppc64el': 'n', 's390x': 'n'}> check-config: FAIL (y != -): CONFIG_CMA_DEBUG policy<{'arm64': 'n', 'armhf': 'n', 'ppc64el': 'n', 's390x': 'n'}> check-config: FAIL (y != -): CONFIG_DMABUF_HEAPS_CMA policy<{'arm64': 'y', 'armhf': 'y'}> check-config: FAIL (7 != -): CONFIG_CMA_AREAS policy<{'arm64': '7', 'armhf': '7', 'ppc64el': '7', 's390x': '7'}> check-config: FAIL (n != -): CONFIG_CMA_SIZE_SEL_MAX policy<{'arm64': 'n', 'armhf': 'n'}> check-config: FAIL (n != -): CONFIG_CMA_SIZE_SEL_MIN policy<{'arm64': 'n', 'armhf': 'n'}> check-config: FAIL (y != n): CONFIG_CMA policy<{'amd64': 'n', 'arm64': 'y', 'armhf': 'y', 'ppc64el': 'y', 's390x': 'y'}> mark note<LP#1362261> note<LP:1803206> check-config: 11433/11447 checks passed -- exit 1

*** ERROR: 2 config-check failures detected

WARNING: configuration operation applied only to a subset of architectures (skipped armhf arm64 ppc64el s390x)

There is an error. How can I solve this? I am running on x64/amd64 platform. I don't really care about these extra platforms for now.

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David

10/30/23, 5:06 PM

The errors are with ARM and you are using AMD You need to find out why.

lorenc

10/30/23, 5:21 PM

It looks like this configuration change is being tested against all supported architectures.

Score:0

Ubuntu

ddker Shanghai

11/9/23, 5:18 PM

the CMA config is intentionally disabled for all platforms other than arm. debian.master/config/annoatations seems to have the amd64 CMA disabled. It might be worth a try to turn it on the same way as arm64, then go through the config and see if it works in your distro. I tested it in Ubuntu 22.04 and it doesn't fail now. But there is a reason in the changelog showing CMA enablement in amd64 causing performance and stability issues, so please use the hack only for testing purpose.

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EN: Error while enabling CMA on ubuntu 20.04 kernel (5.15.0-52-generic)

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