ср, 14 нояб. 2018 г. в 01:53, Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>: > > > > > That must work, but we out of bit space in vm_flags [1]. > > > > i.e. first 32 bits already defined, and other only accessible only on > > > > 64-bit machines. > > > > > > So, grow vm_flags_t to 64-bit, or enable this feature on 64-bit only. > > > > With all due respect to you, for that type of things we need > > mm maintainer opinion. > > As far as I understood, you already got directions from the maintainers > to do similar to the way THP is implemented, and THP uses two flags: > > VM_HUGEPAGE VM_NOHUGEPAGE, the same as I am thinking ksm should do if we > honor MADV_UNMERGEABLE. > > When VM_NOHUGEPAGE is set khugepaged ignores those VMAs. > > There may be a way to add VM_UNMERGEABLE without extending the size of > vm_flags, but that would be a good start point in looking how to add a > new flag. > > Again, you could simply enable this feature on 64-bit only. > > Pasha > Deal! I will try with only on 64bit machines.
