On Fri 05-01-18 14:50:04, Anshuman Khandual wrote: > On 01/05/2018 02:44 PM, Michal Hocko wrote: > > On Fri 05-01-18 09:22:22, Anshuman Khandual wrote: > > [...] > >> Hi Michal, > >> > >> After slightly modifying your test case (like fixing the page size for > >> powerpc and just doing simple migration from node 0 to 8 instead of the > >> interleaving), I tried to measure the migration speed with and without > >> the patches on mainline. Its interesting.... > >> > >> 10000 pages | 100000 pages > >> -------------------------- > >> Mainline 165 ms 1674 ms > >> Mainline + first patch (move_pages) 191 ms 1952 ms > >> Mainline + all three patches 146 ms 1469 ms > >> > >> Though overall it gives performance improvement, some how it slows > >> down migration after the first patch. Will look into this further. > > > > What are you measuring actually? All pages migrated to the same node? > > The mount of time move_pages() system call took to move these many > pages from node 0 to node 8. Yeah they migrated to the same node. > > > Do you have any profiles? How stable are the results? > > No, are you referring to perf record kind profile ? Results were > repeating.
Yes. I am really wondering because there souldn't anything specific to improve the situation with patch 2 and 3. Likewise the only overhead from the patch 1 I can see is the reduced batching of the mmap_sem. But then I am wondering what would compensate that later... -- Michal Hocko SUSE Labs
