On Wed, May 08, 2019 at 03:30:01AM +0000, Po Liu wrote: > > Sorry, NAK, since we decided some time ago not to support timer_* operations > > on dynamic clocks. You get much better application level timer performance > > by synchronizing CLOCK_REALTIME to your PHC and using clock_nanosleep() > > with CLOCK_REALTIME or CLOCK_MONOTONIC. > > The code intend to get alarm by interrupt of ptp hardware. The code > to fix ptp not support to application layer to get the alarm > interrupt. Do you mean the synchronizing at application layer by > PHC (using clock_nanosleep()) to the CLOCK_REALTIME source? Then the > kernel could using the hrtimer with CLOCK_REALTIME?
Yes, or with CLOCK_MONOTONIC. > > > This won't change the user space system call code. Normally the user > > > space set alarm by timer_create() and timer_settime(). Reference code > > > are tools/testing/selftests/ptp/testptp.c. > > > > That program still has misleading examples. Sorry about that. I'll submit > > a > > patch to remove them. > > Is there any replace method for an application code to get alarm interrupt by > the ptp source? No the alarm functionality has been removed. It will not be coming back, unless there are really strong arguments to support it. Here is the result of a study of a prototype alarm method. It shows why the hrtimer method is better. https://sourceforge.net/p/linuxptp/mailman/message/35535965/ Thanks, Richard
