On Tue, 10 May 2022 15:30:36 +0200 Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx> wrote: > > If ksm_force is set to 1, force all anonymous and 'qualified' VMAs > > of this mm to be involved in KSM scanning without explicitly calling > > madvise to mark VMA as MADV_MERGEABLE. But It is effective only when > > the klob of /sys/kernel/mm/ksm/run is set as 1. > > > > If ksm_force is set to 0, cancel the feature of ksm_force of this > > process (fallback to the default state) and unmerge those merged pages > > belonging to VMAs which is not madvised as MADV_MERGEABLE of this process, > > but still leave MADV_MERGEABLE areas merged. > > To my best knowledge, last time a forcible KSM was discussed (see threads [1], [2], [3] and probably others) it was concluded that a) procfs was a horrible interface for things like this one; and b) process_madvise() syscall was among the best suggested places to implement this (which would require a more tricky handling from userspace, but still). > > So, what changed since that discussion? > > P.S. For now I do it via dedicated syscall, but I'm not trying to upstream this approach. Why are you patching the kernel with a new syscall rather than using process_madvise()?
