Hi Marco, Thanks for your reply. Your suggestion fits what I want to do. I had also read up on mmap suggested by Arnold and it appears to have better performance than async. However, it seems more difficult to implement. :-P What I have in mind is to measure timings of events and send the data to userspace. The information will be send via socket to a server. So I think a simple and light solution will suffice. I guess I will go for a poll and async solution. Thanks again. Have a nice day. On Mon, 2002-08-19 at 14:15, Marco Cova wrote: > On Tue, Aug 20, 2002 at 02:59:45AM -0400, Jonathan Khoo wrote: > > Hi guys, > > > > Is it possible for the kernel to push data to the userspace via ioctl > > calls? What I have in mind is for a program in the userspace to open an > > ioctl call to a module, the module is responsible for collecting data > > and whenever there is new updates, the module will push the data to the > > userspace. > > Mmmh, if I understand correctly, the asynchronous notification > mechanism does exactly what you want to do. > > A userspace program registers itself to enable notification from an > input file; the kernel is responsible for sending a SIGIO signal to > registered programs whenever new data is available from that input > file; the program handles the signal and does what it has to do. > > For a detailed description, see: > http://www.xml.com/ldd/chapter/book/ch05.html#t4 > > There are many examples of drivers that use this mechanism, see for > example: > $(linux)/drivers/char/busmouse.c > > HTH, > Marco > > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
