Hi, Miroslav: Thank you so much for your quick and kind response! I uses the TI AM571x IDK EVM.
Best regards, Eric -----Original Message----- From: Miroslav Lichvar [mailto:mlich...@redhat.com] Sent: Friday, October 27, 2017 1:46 AM To: linuxptp-users@lists.sourceforge.net Subject: [EXTERNAL] Re: [Linuxptp-users] question regarding clockcheck_sample() @clockcheck.c On Thu, Oct 26, 2017 at 03:40:27PM +0000, Ruei, Eric via Linuxptp-users wrote: > To whom it may concern: > > We observed that the PTP reported "clockcheck: clock jumped" events when we > added some CPU/Memory load by using stress-ng. > It seemed to us that the problem was triggered by the uncertainty of the > mono_interval = (int64_t)mono_ts - cc->last_mono_ts at this function where > mono_ts is the local time when this routine is called. > There is some uncertainty when the function is called in particular when the > system is busy and therefore there will be a large variance of mono_interval. > ptp4l[1090.977]: interval 119990608 mono_interval 109828955 > ptp4l[1091.110]: interval 130000707 mono_interval 133090775 > ptp4l[1091.226]: interval 120002438 mono_interval 116894219 > ptp4l[1091.373]: interval 130025626 mono_interval 146662543 > ptp4l[1091.500]: interval 120022987 mono_interval 126504891 > ptp4l[1091.607]: interval 129964127 mono_interval 106861426 > ptp4l[1091.608]: clockcheck: clock jumped forward or running faster than > expected! > > Is it expected behavior? If a very short sync interval is used and the process may run up to 20 milliseconds late, then yes, I think it's expected that the clock check in default configuration will have false positives. You may want to increase or disable sanity_freq_limit. Just curious, on what hardware do you see this? -- Miroslav Lichvar ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
