Hi, I am just trying to solve a similar problem as Luca described. I have a TQMa28 board running Linux 3.17-rc7 though. The capacitors keep the system up for about 1500 more milliseconds after the power fails. A GPIO line is set to high as soon as the main power is lost. So I have not much time to quit an important user space process and to clean up the ext4 root filesystem before the power fails. At the moment I pass rootflags=data=journal,commit=1 in the kernel commandline to lower the risk of data loss. In the user space application I open important files using the O_SYNC flag. Is there something else I should do to avoid data loss? How would you implement the "emergency cleanup on power-failure" logic? Dedicated driver (similar to the mentioned gpio-event driver?), implement it with UIO, let a userspace application running as root select /dev/uioX and cleaning up? Or should I create a separate partition on my eMMC just for this user space application data and use a readonly rootfs for the rest? Thanks for your help! Best regards, Clemens _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
