On Sat, Jul 22, 2023 at 04:12:32PM +0200, jmfriedt wrote: > To do this I am connecting an Ettus Research X310 software defined > radio to the CM4 and configuring to start collecting data upon > detection of the WR 1PPS rising edge. The SDR input is connected to the > 1PPS to assess that the record always stays at the same time with > respect to the 1PPS and it does. I record a known number of samples in > file.bin at a known datarate (5 MS/s) and look at the timestamp of the > last file access as the last field of stat -c %y file.bin, and I try > and analyze the factional part of this timestamp.
How exactly you are writing to that file? Any buffering or fsync()? I think the modified timestamp of a file is captured by the kernel when it's updating the inode. The system clock might be precise to few tens of nanoseconds, but that update of the inode certainly cannot be timed to such precision. -- Miroslav Lichvar _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
