Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: David Hildenbrand on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_567589295 @arozansk @ddutile @llong1 It would be great if you could have another look at v3 -- thanks! ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: Rafael Aquini on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_558913497 Thanks David, that's fair enough. Works with me! ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: David Hildenbrand on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_558576985 I consider it as helpful on ppc64 and s390x as well to troubleshoot, just to know that CMA allocations happened. After all, it's a single pr_info() we'll spot in dmesg. However, if there are real concerns, I can modify this. Thanks! ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: Rafael Aquini on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_558452775 David, minor question: don't we want to follow the same !IS_ENABLED(CONFIG_S390) && !IS_ENABLED(CONFIG_PPC64) check here, as well? ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: David Hildenbrand on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_556204600 Yes, that's what the current patches do (feel free to review and eventually ack ;) ) Thanks! ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: Rafael Aquini on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_556194632 I don't have a strong opinion on this one, but I think should perhaps go with (albeit weird) the conditional tainting for x86_64 and Aarch64. Reason CMA was disabled in RHEL8 basically boils down to: a) it was disabled in kernel-alt, due to reported problems with Aarch64; b) the (RHEL-7) early dependency on CMA to grab 1GB pages at runtime was dismissed by the original reporter of that need. ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: David Hildenbrand on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_554101592 Right, if the user manually specifies "cma=2G" and the system is not able to cope with that, this is a clear configuration error and once supported, we would want to document that -- there are other cases where having too much CMA memory can be problematic. Regarding s390x/cma: they reserve other CMA regions, not the default one (cmd=XX); we'd want to specify: - vmcp_cma=0 on s390x - kvm_cma_resv_ratio=0 on ppc64 However, the s390x version is not too bad (-> 4 MiB), so maybe we want to leave that untouched. ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: Dave Young on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_554095592 Hi David, Ok, I had a discussion in kdump team, for X86 since we have crashkernel=,high and we can reserve more in high memory region so the risk is low. The only case is what you mentioned if someone allocate cma=2G then kdump resrevation may fail if the system ram is small. As the default CMA_SIZE_MBYTES is 0 we should be fine to the change. As for kdump kernel, we can pass cma=0 in userspace via 2nd kernel cmdline param, can cma=0 override the behavior in ppc64/s390 as you mentioned? ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: David Hildenbrand on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_552329069 Sure, but keep in mind that it will be tech preview and is similarly enabled already in Fedora. However, you remind me of an interesting case: kdump and CMA reservations We would be in trouble if we were to automatically create big CMA regions in the kdump kernel (where we have limited memory), either from the kernel, like with CMA_SIZE_MBYTES, or via cmdline, like "cmd=2G". While often such allocations attempts will fail and still allow the kdump kernel to boot, there can be cases where it will "just work" and kdump itself might later because it doesn't have sufficient memory available. Fortunately, on x86-64 we we have CMA_SIZE_MBYTES set to 0 MiB and our kdump kernel won't be booted with any "cma=", "hugetlb_cma=" parameters that might have been specified for the !kdump kernel. So there, we seem to be fine. On s390x, we reserve as default a CMA region with 4 MiB. On ppc64 with HV support, we reserve as default a CMA region with 5% of the memblock_phys_mem_size() for KVM use; We might want to disable the latter via is_kdump_kernel() upstream. ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
Re: [OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: Dave Young on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023#note_552056585 There might be some side effects to kdump crashkernel reservation. Kdump team need to do some test quickly first. ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
[OS-BUILD PATCHv2 0/2] enable CONFIG_CMA on x86_64 in ARK
From: David Hildenbrand on gitlab.com Merge Request: https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1023 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1945002 Enable CONFIG_CMA on x86_64 in ARK as we already have in fedora; CMA is Tech Preview in RHEL 9. ___ kernel mailing list -- kernel@lists.fedoraproject.org To unsubscribe send an email to kernel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
