Hi the need for sending a signal from kernel to user is explained below: i have a single process running in the user space which has 2 threads..say TA and TB. associated with each is a device DEVA and DEVB and their respective drivers DrvA and DrvB. when ever DrvA needs to send some signal to the user on some interrupt, it is done through the fasync method by sending the SIGIO signal. This signal is sent to the process and is handled by the thread TA. Now a need comes where i need to send a similar kind of notification from the kernel to the thread TB, which gets the signal from DrvB. since TA and TB are threads, and both expect the same signal , when the signal is reached to the thread, it is not identified as to where the signal has arrived from ..ie, DrvA has signalled or DrvB has signalled. Is there anyway we can achieve this fasync method by any other signal also other than the SIGIO ?? or is it that only SIGIO is used to notify the user asynchronously?? Regards, Vijay Ram.C On Fri, 15 Jul 2005, Thomas Petazzoni wrote: > Hello, > > Vijay Ram Chitrapu (RCVIJAYD) wrote: > > > i was under an idea that software interrupts can be used to send > > some kind of signals to the user space asynchronously. Is it possible > > for a driver running in the kernel to generate a software interrupt > > asynchronously to the user such that the user is informed of some change > > in the kernel the driver is involved with? I am well aware of the fasync > > method of asynchronous notification..but want to know if this way of > > signalling is feasible or not? > > Actually, I don't know what is the good (tm) solution to signal a > userspace process. I'm not sure sending a signal is a good idea. There > is inotify, but it's really designed for this. Really, I don't know. > > Can you be more precise about the cases in which you need kernel->user > signaling ? > > Sincerly, > > Thomas > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
