==>On Mon, Mar 11, 2002 at 06:15:13AM -0600, pwa wrote: ==> ==>> AFAIK if the process (#1) holding the spinlock blocks while calling ==>> copy_to_user, schedule is ==>> called. The next process (#2) tries to enter the critical region, and spins ==>> on the lock. ==>> If/when the pages requested by the copy_to_user are retrived from swap, an ==>> interrupt should occur. ==>> Schedule should mark #1 as running, and #1 should release the lock. ==> ==>kernel tasks can't be pre-empted (without CONFIG_PREEMPT) yes, kernel tasks can'nt be pre-empted, but they can voluntarily release CPU on blocking.But I don't think that if you block in copy_to_user, scheduler is called. So that there will be no deadlock. Ketan -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
