On 10 Apr 2020, at 10:58, Kirill A. Shutemov wrote: > External email: Use caution opening links or attachments > > > On Fri, Apr 10, 2020 at 10:36:58AM -0400, Zi Yan wrote: >> On 10 Apr 2020, at 7:47, Kirill A. Shutemov wrote: >> >>> External email: Use caution opening links or attachments >>> >>> >>> On Mon, Apr 06, 2020 at 10:59:52AM -0400, Zi Yan wrote: >>>> I ran this test with all patches from this series applied to Linus’s tree, but still see several failures. Is it expected? >>>> The config file is attached. Let me know if I miss anything. BTW, I am running in a VM. >>>> >>>> Thanks. >>>> >>>> The output: >>>> >>>> ➜ ~ sudo ./khugepaged >>>> Save THP and khugepaged settings... OK >>>> Adjust settings... OK >>>> Allocate huge page on fault... OK >>>> Split huge PMD on MADV_DONTNEED... OK >>>> Collapse fully populated PTE table.... Fail >>> >>> I was able to reproduce the issue. And it's fun failure mode. >>> >>> How did you get the test case inside the VM? Copy-paste source using 'cat' >>> or something similar inside the VM? >> >> First of all, the failure above was from a bare metal and was the only >> failure I saw, whereas I saw more failures in my VM. The test program >> was not messed up in either environment. > > Hm. In the quote you are saying "BTW, I am running in a VM". Sorry, misread the email thread. I was referring to another my email on running tests on a bare metal, where only “Collapse with max_ptes_swap pages swapped out” failed. Here is the link to the email: https://lore.kernel.org/linux-mm/C66E1309-2069-495B-BACD-7F3282C6EC7D@xxxxxxxxxx/ > >> >> For VM failures I mentioned before, I used scp to copy the source code >> into the VM. My VM has its port 22 forwarded to host’s port 11022. “-net >> user,hostfwd=tcp::11022-:22”. I also copied a binary into my VM and saw >> the same failures. >> >> I kinda think the failures are not related to your patches but something else. >> >>> >>> It screwed up CHECK_HUGE_FMT and CHECK_SWAP_FMT for me. Double back slash >>> was converted to single. As result check_huge() and check_swap() gave the >>> false-negative result all the time. >> >> It was not my case, since CHECK_HUGE_FMT and CHECK_SWAP_FMT from my >> khugepaged.c match your patch code. >> >>> >>> Could you check that the source of the test-case is not mangled and >>> re-test if it is. >> >> I can confirm that the test-case is not mangled. I think it must be my >> VM setup or kernel configuration. >> >> Do you mind sharing your .config file with me and which kernel commit >> you apply the patches on top of in your setup? I can look into it and >> check what the problem is. > > My config is attached. Thanks. — Best Regards, Yan Zi
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