On 8/21/26 01:55, Yeoreum Yun wrote: > On Thu, Aug 20, 2026 at 07:37:29PM -0400, Zi Yan wrote: >> On Thu Aug 20, 2026 at 5:23 PM EDT, Yeoreum Yun wrote: >>> >>> Well, this also works with hugepage_save_settings() and write the >>> khugepaged/scan_sleep_millisecs with the maximum integer. >>> >>> I don't have a strong opinion but since it seems more hackish way to >>> change scan_sllep_millisecs, I use madvise() with MADV_NOHUGEPATE. >>> >>> Would it be better to change using APIs in hugepage_setting,h? >> >> No. I did not realize there is no way of stopping khugepaged completely. >> >> BTW, I am curious about your khugepaged config causing this issue. >> IIRC, khugepaged scan interval is about minutes and >> the time between madvise(MADV_HUGEPAGE) and the second >> is_backed_by_folio() should not be that long. > > Yes. it's relly timing sensitive and I've failed to reproduce in the > real hardware. but in the emulation environment it often failed with > the scan_sllep_millisecs as 10 seconds while the test running. > >> >> For your patch, maybe you want to check the return value of madvise() to >> make sure it succeeds. > > Yeap. but it seems enough just worning message for the madvise() with > MADV_NOHUGEPAGE.
Yeah, I assume we can assume that we are running on a recent enough kernel that supports MADV_NOHUGEPAGE. -- Cheers, David
