On Wed 28-06-17 11:23:32, Prakash Sangappa wrote: > > > On 6/28/17 6:18 AM, Mike Rapoport wrote: [...] > >I've just been thinking that maybe it would be possible to use > >UFFD_EVENT_REMOVE for this case. We anyway need to implement the generation > >of UFFD_EVENT_REMOVE for the case of hole punching in hugetlbfs for > >non-cooperative userfaultfd. It could be that it will solve your issue as > >well. > > > > Will this result in a signal delivery? > > In the use case described, the database application does not need any event > for hole punching. Basically, just a signal for any invalid access to > mapped area over holes in the file. OK, but it would be better to think that through for other potential usecases so that this doesn't end up as a single hugetlb feature. E.g. what should happen if a regular anonymous memory gets swapped out? Should we deliver signal as well? How does userspace tell whether this was a no backing page from unavailable backing page? -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
