On Sun, 05 Nov 2000 12:28:55 +1100, Andrew Morton <andrewm@uow.edu.au> wrote: > CPU0 CPU1 > > rtnl_lock() > dev_ifsioc() > dev_change_flags() > dev_open(); > dev->open(); > vortex_open() > sys_delete_module() > if (!__MOD_IN_USE) > free_module() If dev->open() calls try_inc_use_count() before it enters the module you will lock out concurrent module unload via module unload_lock. There is no need for another module semaphore. Also there is no need to test dev->owner, try_inc_use_count() already does that. /* * Call device private open method */ ret = -ENODEV; if (try_inc_mod_count(dev->owner)) { if (dev->open && (ret = dev->open(dev)) && dev->owner) __MOD_DEC_USE_COUNT(dev->owner); } In dev_close() /* * Call device private close method */ if (dev->owner) __MOD_DEC_USE_COUNT(dev->owner); - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org