This series aim at the following enhancement - 1. Let one hwpoison injector, that is, madvise(MADV_HWPOISON) to behave more like as if a real UE occurred. Because the other two injectors such as hwpoison-inject and the 'einj' on x86 can't, and it seems to me we need a better simulation to real UE scenario. 2. For years, if the kernel is unable to unmap a hwpoisoned page, it send a SIGKILL instead of SIGBUS to prevent user process from potentially accessing the page again. But in doing so, the user process also lose important information: vaddr, for recovery. Fortunately, the kernel already has code to kill process re-accessing a hwpoisoned page, so remove the '!unmap_success' check. 3. Right now, if a thp page under GUP longterm pin is hwpoisoned, and kernel cannot split the thp page, memory-failure simply ignores the UE and returns. That's not ideal, it could deliver a SIGBUS with useful information for userspace recovery. Jane Chu (3): mm/memory-failure: try to send SIGBUS even if unmap failed mm/madvise: Add MF_ACTION_REQUIRED to madvise(MADV_HWPOISON) mm/memory-failure: send SIGBUS in the event of thp split fail mm/madvise.c | 2 +- mm/memory-failure.c | 49 ++++++++++++++++++++++++++++++++++++--------- 2 files changed, 41 insertions(+), 10 deletions(-) -- 2.39.3
