Thanks, David! On Thu, Feb 22, 2024 at 4:51 PM David Hildenbrand <david@xxxxxxxxxx> wrote: > > On 22.02.24 08:51, Lance Yang wrote: > > Hey, > > > > On an Intel Core i5 CPU, the time taken by > > khugepaged to scan the address space of > > the process, which has been set with the > > MMF_DISABLE_THP flag after being added > > to the mm_slots list, is as follows (shorter is better): > > > > VMA Count | Old | New | Change > > --------------------------------------- > > 50 | 23us | 9us | -60.9% > > 100 | 32us | 9us | -71.9% > > 200 | 44us | 9us | -79.5% > > 400 | 75us | 9us | -88.0% > > 800 | 98us | 9us | -90.8% > > > > IIUC, once the count of VMAs for the process > > exceeds page_to_scan, khugepaged needs to > > wait for scan_sleep_millisecs ms before scanning > > the next process. IMO, unnecessary scans could > > actually be skipped with a very inexpensive > > mm->flags check in this case. > > FWIW > > Acked-by: David Hildenbrand <david@xxxxxxxxxx> > > -- > Cheers, > > David / dhildenb >
