On February 01, 2017 3:54 AM Zi Yan wrote: > > I am also doing some tests on THP migration and discover that there are > some corner cases not handled in this patchset. > > For example, in handle_mm_fault, without taking pmd_lock, the kernel may > see pmd_none(*pmd) during THP migrations, which leads to > handle_pte_fault or even deeper in the code path. At that moment, > pmd_trans_unstable() will treat a pmd_migration_entry as pmd_bad and > clear it. This leads to application crashing and page table leaks, since > a deposited PTE page is not released when the application crashes. > > Even after I add is_pmd_migration_entry() into pmd_trans_unstable(), I > still see application data corruptions. > > I hope someone can shed some light on how to debug this. Should I also > look into pmd_trans_huge() call sites where pmd_migration_entry should > be handled differently? > Hm ... seems it helps more if you post your current works as RFC on top of the mm tree, and the relevant tests as well. Hillf > > Anshuman Khandual wrote: > > On 11/08/2016 05:01 AM, Naoya Horiguchi wrote: > >> Hi everyone, > >> > >> I've updated thp migration patches for v4.9-rc2-mmotm-2016-10-27-18-27 > >> with feedbacks for ver.1. > > > > Hello Noaya, > > > > I have been working with Zi Yan on the parallel huge page migration series > > (https://lkml.org/lkml/2016/11/22/457) and planning to post them on top of > > this THP migration enhancement series. Hence we were wondering if you have > > plans to post a new version of this series in near future ? > > > > Regards > > Anshuman > > > > -- > Best Regards, > Yan Zi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
