Roland Dreier wrote: > > Can I this version already solved fork() + COW issue? if so, could you > > please explain what happen at fork. Obviously RDMA point to either parent > > or child page, not both. but Corrent COW rule is, first touch process > > get copyed page and other process still own original page. I think it's > > unpecected behavior form RDMA. > > No, ummunotify doesn't really help that much with fork() + COW. If a > parent forks and then touches pages that are actively in use for RDMA, > then of course they get COWed and RDMA goes to the wrong memory (from > the point of view of the parent). >
My understanding of the code is that fork will end-up calling copy_page_range() on all VMA, and copy_page_range() calls mmu_notifier_invalidate_range_start() if is_cow_mapping() is true, which should be the case here. So you should get some invalidate events on fork. Brice -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
