On 2024/5/7 3:54, Jane Chu wrote: > On 5/5/2024 12:02 AM, Miaohe Lin wrote: > >> On 2024/5/2 7:24, Jane Chu wrote: >>> The soft hwpoison injector via madvise(MADV_HWPOISON) operates in >>> a synchrous way in a sense, the injector is also a process under >>> test, and should it have the poisoned page mapped in its address >>> space, it should legitimately get killed as much as in a real UE >>> situation. >> Will it be better to add a method to set MF_ACTION_REQUIRED explicitly when inject soft hwpoison? >> Thanks. > > So the first question is: Is there a need to preserve the existing behavior of madvise(MADV_HWPOISON)? > > The madvise(2) man page says - > > *MADV_HWPOISON *(since Linux 2.6.32) > Poison the pages in the range specified by/addr/ and/length/ > and handle subsequent references to those pages like a > hardware memory corruption. This operation is available > only for privileged (*CAP_SYS_ADMIN*) processes. This > operation may result in the calling process receiving a > *SIGBUS *and the page being unmapped. > > This feature is intended for testing of memory error- > handling code; it is available only if the kernel was > configured with*CONFIG_MEMORY_FAILURE*. > > And the impression from my reading is that: there doesn't seem to be a need. > > A couple observations - > - The man page states that the calling process may receive a SIGBUS and the page being unmapped. > But the existing behavior is no SIGBUS unless MCE early kill is elected, so it doesn't quite match > the man page. > - There is 'hwpoison-inject' which behaves similar to the existing madvise(MADV_HWPOISON), that is, > soft inject without MF_ACTION_REQUIRED flag. > I tend to agree with you. It might be a good idea to add MF_ACTION_REQUIRED to madvise(MADV_HWPOISON). Thanks. .
