I am trying to understand the behavior of the libibverbs after it has been set into fork safe mode via a successful call to ibv_fork_init() or setting the environmental variable IBV_FORK_SAFE. For my purposes I would like to know the following :
Are PDs, QPs and CQs created before a fork shared by the parent and child after fork() has returned (ie. both can submit WRs, poll CQ, etc.)? What about MRs registered before the fork? Even though the child doesn't have access to the parent's memory, can he sill submit WRs on a QP with an MR created before the fork? What if the MR pages in the above scenario are accessible in both parent and child (shared memory)? Are there complications with registering shared memory? In general, are pointers returned by libibverbs pointer to user/process address space (as ibv_mr pointers must be) or kernel space (eg. if an unrelated process had another process's QP pointer, lkey, and a virtual address could it post (almost certainly unsafely) a WR to the other process's QP? Sorry if the questions seem progressively more goofy and thanks in advance for any clarification. -Matt -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
