> What you could do to schedule some kernel code to run, is > make a user space > prog which write's to a device or /proc entry, this can > trigger the code to > run..... In what context? To access userspace data, you must be in a process context. Fx. you cannot access userspace data from an interrupt. Or do you think the process that opens the device, just place the data somewhere trigger a bit to tell that the data is there. And then puts itself on the queue and waits, for some other kernel process to take care of the data, and to wake the process again? In a module you can call sleep_on_timeout(), that puts you on the queue, instead of making a busy wait. How would this be possible if there isn't any process context in the execution? Take a look at /proc/self, it is a symbolic link to the /proc entry of the current process, if you look at the link from another shell (and thereby another pid) you will see that the link has changed, to point at you new pid. How come that? Take look at linux/fs/proc/base.c and the function proc_self_readlink() (line 915 in 2.4.18). It uses the current->pid variable to make the symbolic link. How come this work if the are no pid in kernel code? -- Martin Hansen Student at SDU Sønderborg. www.sdu.dk Writing final project at Danfoss drives A/S. http://drives.danfoss.com Tlf: 74 88 54 62 -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
