Messages in this thread | | | Date | Thu, 30 Dec 1999 16:53:52 +0200 (IST) | From | Mark Mokryn <> | Subject | sleep_on, wake_up question |
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I'm working on a module, in which my ioctl function fuction needs to block, waiting for the hardware to do its work (in an ISR/bottom half). Code looks like: my_ioctl() { ... // prepare work for adapter, and interrupt it interruptible_sleep_on(&wq); ... }
adapter_isr() { // do some work wake_up_interruptible(&wq); ... }
It's possible that the PC will be interrupted (by anything) just prior to the sleep_on call in my_ioctl, and eventually, the adapter may even complete its work (and call wake_up) before the sleep_on function was even reached. In a heavily loaded system, this possibility is more than theoretical. In this case, it appears that the calling process may forever hang in sleep_on. Help? Am I missing something here? Perhaps there should be a signalling mechanism in wake_up, so that if necessary, sleep_on may complete immediately? No such mechanism on kernel sources I browsed (2.2.12).
Thanks, -Mark
Mark Mokryn mark@psl.technion.ac.il Tel: 972-2-5702983
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