On Wed, Jan 18, 2023 at 10:11:46AM +0100, Michal Hocko wrote: > On Tue 17-01-23 15:16:32, Minchan Kim wrote: > > madvise LRU manipulation APIs need to scan address ranges to find > > present pages at page table and provides advice hints for them. > > > > Likewise pg[scan/steal] count on vmstat, madvise_pg[scanned/hinted] > > shows the proactive reclaim efficiency so this patch addes those > > two statistics in vmstat. > > Please describe the usecase for those new counters. I wanted to know the proactive reclaim efficieny using MADV_COLD/MDDV_PAGEOUT. Userspace has several policy which when/which vmas need to be hinted by the call and they are evolving. I needed to know how effectively their policy works since the vma ranges are huge(i.e., nr_hinted/nr_scanned).
