On 3/30/20 7:01 AM, Naresh Kamboju wrote: > FYI, > > The device is x86_64 device running i386 kernel image. > > - Naresh > > On Mon, 30 Mar 2020 at 19:00, Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> wrote: >> >> On i386 running LTP hugetlb tests found kernel BUG at fs/hugetlbfs/inode.c:458 >> Running Linux version 5.6.0-rc7-next-20200330 >> And hugemmap test failed due to ENOMEM. >> >> steps to reproduce: >> # cd /opt/ltp >> # ./runltp -f hugetlb It took me a while to set up an environment to reproduce. I was finally able to reproduce on an x86_64 VM running a 32 bit OS/5.6.0-rc7-next-20200330 kernel. My first attempt with PAE enabled and 8GB of memory did not reproduce. When I disabled PAE and dropped memory to 4GB, the problem reproduced. After reverting this patch, and the followup in the series I was still able to recreate the issue. So, the patches are not the root cause. One 'interesting' thing are the messages, mm/pgtable-generic.c:50: bad pgd ... These show up before the hugetlbfs BUG. I will continue to investigate. However, if the 'bad pgd ..' message provides a hint to someone please let us know. -- Mike Kravetz
