On Sat, 22 Aug 2020, Sasha Levin wrote:
I've followed your instructions and backported the patches:
bbe98f9cadff ("khugepaged: khugepaged_test_exit() check mmget_still_valid()") - to all branches. f3f99d63a815 ("khugepaged: adjust VM_BUG_ON_MM() in __khugepaged_enter()") - to all branches. 59ea6d06cfa9 ("coredump: fix race condition between collapse_huge_page() and core dumping") - for 4.4.
That's saved me time, thanks a lot for doing that work, Sasha.
I've checked the results (haha, read on) and they're all fine, but one minor flaw in bisectability: the added 4.4 backport of "coredump: fix race condition..." adds a line (deleted by the next commit) result = SCAN_ANY_PROCESS; but neither "result" nor "SCAN_ANY_PROCESS" is defined in that tree, so that intermediate step would generate an easily fixed build error.
FWIW - I don't know whether that's something to care about or not.
Thanks again, Hugh