On 08.03.22 22:34, Zach O'Keefe wrote: > In madvise collapse context, we optionally want to be able to ignore > advice from MADV_NOHUGEPAGE-marked regions. > > Add a vm_flags_ignore argument to hugepage_vma_revalidate_pmd_count() > which can be used to ignore vm flags used when considering thp > eligibility. arch/s390/mm/gmap.c:thp_split_mm() sets VM_NOHUGEPAGE to make sure there are *really* no thp. Being able to bypass that would break KVM horribly. Ignoring MADV_NOHUGEPAGE/VM_NOHUGEPAGE feels like the wrong way to go. What about a prctl instead, to disable any khugepagd activity and just let that process control it manually? -- Thanks, David / dhildenb
