* Daniel Walker <dwalker@xxxxxxxxxx> wrote: > On Sat, 2007-11-17 at 18:46 +0100, Ingo Molnar wrote: > > * Daniel Walker <dwalker@xxxxxxxxxx> wrote: > > > > > > Actually, IMO, compat_semaphores behave like semaphores should > > > > behave, and thus the same as they behave on a non-RT kernel, and at > > > > the locations where the semaphores are now misused as mutexes on RT, > > > > we should replace them by differently-named-mutex-type-semaphores, > > > > or better: real-RT-mutexes.. > > > > > > The vast majority of semaphore are actually binary semaphores in the > > > Linux kernel .. So it's easier to mass convert semaphores to mutexes, > > > then address the ones that don't conform.. Usually they are converted > > > to the complete API in mainline.. > > > > right now there are 3992 mutex_lock() critical sections in the kernel > > and only 351 down() based critical sections are left. > > > > fixing the top 20: > > > > 4 &vuart_bus_priv.probe_mutex > > 5 &connections_lock > > 5 &irq_ptr->setting_up_sema > > 5 &kbd->sem > > 5 &pnp_res_mutex > > 5 &port->port_lock > > 5 &tq_init_sem > > 6 &adb_handler_sem > > 6 &dev->parent->sem > > 6 &driver_lock > > 6 &ha->vport_sem > > 7 &big_buffer_sem > > 8 &dir_f->sem > > 9 &c->alloc_sem > > 11 &dev->sem > > 11 &usbvision->lock > > 12 &c->erase_free_sem > > 15 &u132->scheduler_lock > > 16 &zfcp_data.config_sema > > 17 &f->sem > > > > would remove 164 of them, so it would convert half of the remaining > > semaphore use in the kernel. So the job is almost finished - would > > anyone like to go for the final grand feat: complete removal of > > semaphores from the kernel? :-) > > Sure, you want to split the list? split the list with you? Feel free to take any of those :-) dev->sem is nontrivial and probably not possible right now - and some of the others might be problematic too. But there might be fixable ones in the list. This shouldnt become like the BKL conversion - never truly finished. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
