On Wed, Mar 15, 2023 at 12:55:56PM +0100, Maciek Machnikowski wrote: > The SHM is not cleared upon servo release when exiting the tool. This leaves > the last update in the shared memory region marked as valid. As a result, the > NTP daemon starting later may consume stale data if the producer process > exited. > > To prevent such behavior - invalidate the SHM data when releasing the SHM > servo.
It probably doesn't matter much either way, but this doesn't seem right to me. The sample stays valid after ptp4l/phc2sys exited. There is a timestamp when the measurement was made. It's up to the consumer to check if it's still acceptable. The same situation happens when the servo stops due the port switching to another PTP state without exiting. The last sample was made when the source clock was considered synchronized and it can be used for synchronization of the system clock. -- Miroslav Lichvar _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
