Hi, we recently discovered that our application was not able to create new threads or perform mmaps after some time. With some digging we identified the function ixgbe_dev_link_update_share() to be the reason for this behavior.
In the patch "net/ixgbe: fix blocking system events" (819d0d1d57f17aa40321648e99a50b49adc7bdf6) a thread is introduced to run ixgbe_dev_setup_link_thread_handler(). Unfortunately this thread is not detached and just joined (the very last one spawned that is) through ixgbe_dev_cancel_link_thread() upon interface start/stop. When an application repeatedly calls e.g. rte_eth_link_get_nowait() on an ixgbe interface with no link this causes a lot of pthreads never to be cleaned up. Since each thread holds a mmap to the stack this can quite quickly exhaust the allowed number of memory mappings for the process. Best regards, Martin Weiser