On Tue, Jun 15, 2010 at 10:33:51AM -0600, Grant Likely wrote: > > +config NETWORK_PHY_TIMESTAMPING > Some overhead? At a brief glance of the series it looks like it could > add a lot of overhead, but I'm not fully clear on what the full > process is. Can you describe how the hardware timestamping works? I > could use an overview of what the kernel has to do.
First of all, I want to emphasize that this network stack option is purely voluntary. Only those people who know that they have a PTP capable PHY and really want the timestamps will (or should) enable this option. When it is not enabled, it has no effect at all. Hardware timestamping is described in Documentation/networking/timestamping.txt Documentation/networking/timestamping/timestamping.c The PTP subsystem is described in Documentation/ptp/ptp.txt There really is more to say about the issue than appears in those documents, but they are a good starting place for discussion. BTW I am submitting a conference paper on the design on the PTP subsystem. If you would like to have it, just ask me off-list. Richard _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
