Hi ravi it shows always same PID value irrespective of which process has called driver read/write function. -potluri +++++++++++++++++++++++++++++++ Disclaimer +++++++++++++++++++++++++++++++++++++++ This e-mail may contain privileged and confidential information and is intended only for the use of the specific individual(s) to whom it is addressed. If you are not an intended recipient of this e-mail, you are hereby notified that any unauthorized use, dissemination or copying of this e-mail or the information contained in it or attached to it is strictly prohibited. If you have received this e-mail in error, please delete it and immediately notify the undersigned by reply e-mail. Hellosoft India Pvt. Ltd. www.hellosoft.com +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/