Messages in this thread | | | From | Mahesh Bandewar (महेश बंडेवार) <> | Date | Sat, 6 Jan 2024 00:08:57 -0800 | Subject | Re: [PATCHv3 net-next 2/3] ptp: add ioctl interface for ptp_gettimex64any() |
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On Fri, Jan 5, 2024 at 8:55 PM Richard Cochran <richardcochran@gmail.com> wrote: > > On Fri, Jan 05, 2024 at 09:51:40AM -0800, Mahesh Bandewar (महेश बंडेवार) wrote: > > > POSIX clocks are employed in this series for syscall width > > measurement, potentially leading to misunderstandings about > > overlapping functionality. However, their roles are distinct and serve > > different purposes. > > I don't see any difference in purposes. The multi_clock_gettime call > is a more general solution. Thus it will obviate the need for any new > PTP ioctls. >
I disagree! NICs inherently benefit from bundled PTP devices due to their superior low-latency, low-overhead, and precise TX/RX timestamping capabilities. For demanding systems requiring increased capacity, multiple NICs from various vendors are often deployed. However, disciplining these diverse PTP devices across the host demands a flexible approach; a general purpose syscall is not an answer. The current PHC implementation using ioctls through exported ptp devices (/dev/ptpX) provides a solid foundation that is per device (/per NIC).
This series is providing another piece in an existing suite of methods used for disciplining / precision tuning (along with adjfine, adjtime, gettime etc.) This addition is to take that precision even further.
Having a general solution for posix timers is a nice addition. However, expecting a general purpose syscall to eliminate need for device ioctl is an unreasonable expectation.
Thanks, --mahesh..
> Thanks, > Richard
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