Hi, Any feedback on this patch would be appreciated. I believe this patch is useful for improving the performance of the nullf servo, when write_phase_mode is enabled. Provided below is demonstration of the performance benefits of the patch. By transitioning to state s3 (SERVO_LOCKED_STABLE), we see improved stability and a smaller drift below the 4000ns range.
Setup used in testing both cases -------------------------------- * A ptp clock device with ADJ_OFFSET supported Key configuration settings used ------------------------------- step_threshold 0.00002 first_step_threshold 0.000000001 clock_servo nullf servo_offset_threshold 100000 write_phase_mode 1 Using the nullf servo without the patch --------------------------------------- ptp4l[1901.436]: selected /dev/ptp1 as PTP clock ptp4l[1901.437]: port 1 (eth2): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[1901.437]: port 0 (/var/run/ptp4l): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[1901.437]: port 0 (/var/run/ptp4lro): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[1908.273]: port 1 (eth2): LISTENING to MASTER on ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES ptp4l[1908.273]: selected local clock 0c42a1.fffe.d1d0d4 as best master ptp4l[1908.273]: port 1 (eth2): assuming the grand master role ptp4l[1914.276]: port 1 (eth2): new foreign master 0c42a1.fffe.d1d084-1 ptp4l[1918.276]: selected best master clock 0c42a1.fffe.d1d084 ptp4l[1918.276]: port 1 (eth2): MASTER to UNCALIBRATED on RS_SLAVE ptp4l[1920.275]: master offset 3880206 s1 freq +0 path delay -1304 ptp4l[1921.276]: master offset -57638 s1 freq +0 path delay -1304 ptp4l[1922.275]: master offset 7514 s0 freq +0 path delay -1304 ptp4l[1923.275]: master offset 11241 s0 freq +0 path delay -1091 ptp4l[1924.275]: master offset 15193 s0 freq +0 path delay -1091 ptp4l[1925.275]: master offset 18924 s0 freq +0 path delay -878 ptp4l[1926.277]: master offset 22722 s1 freq +0 path delay -728 ptp4l[1927.276]: master offset 4434 s0 freq +0 path delay -728 ptp4l[1928.276]: master offset 8224 s0 freq +0 path delay -578 ptp4l[1929.276]: master offset 12468 s0 freq +0 path delay -878 ptp4l[1930.276]: master offset 16420 s0 freq +0 path delay -878 ptp4l[1931.277]: master offset 20360 s1 freq +0 path delay -878 ptp4l[1932.276]: master offset 4344 s0 freq +0 path delay -878 ptp4l[1933.276]: master offset 8423 s0 freq +0 path delay -1009 ptp4l[1934.276]: master offset 12367 s0 freq +0 path delay -1009 ptp4l[1935.276]: master offset 16487 s0 freq +0 path delay -1189 ptp4l[1936.277]: master offset 20431 s1 freq +0 path delay -1189 ptp4l[1937.276]: master offset 4347 s0 freq +0 path delay -1189 ptp4l[1938.276]: master offset 8287 s0 freq +0 path delay -1189 ptp4l[1939.276]: master offset 12215 s0 freq +0 path delay -1189 ptp4l[1940.276]: master offset 16050 s0 freq +0 path delay -1080 ptp4l[1941.276]: master offset 19716 s0 freq +0 path delay -806 ptp4l[1942.278]: master offset 23934 s1 freq +0 path delay -1080 ptp4l[1943.276]: master offset 4502 s0 freq +0 path delay -1080 ptp4l[1944.276]: master offset 8387 s0 freq +0 path delay -1025 ptp4l[1945.276]: master offset 12327 s0 freq +0 path delay -1025 ptp4l[1946.276]: master offset 16165 s0 freq +0 path delay -919 ptp4l[1947.278]: master offset 20093 s1 freq +0 path delay -919 ptp4l[1948.277]: master offset 4329 s0 freq +0 path delay -919 ptp4l[1949.277]: master offset 8371 s0 freq +0 path delay -1025 ptp4l[1950.277]: master offset 12311 s0 freq +0 path delay -1025 ptp4l[1951.277]: master offset 16247 s0 freq +0 path delay -1025 ptp4l[1952.278]: master offset 20191 s1 freq +0 path delay -1025 ptp4l[1953.277]: master offset 4323 s0 freq +0 path delay -1025 ptp4l[1954.277]: master offset 8382 s0 freq +0 path delay -1148 ptp4l[1955.277]: master offset 12322 s0 freq +0 path delay -1148 ptp4l[1956.277]: master offset 16262 s0 freq +0 path delay -1148 ptp4l[1957.278]: master offset 20194 s1 freq +0 path delay -1148 ptp4l[1958.277]: master offset 4338 s0 freq +0 path delay -1148 ptp4l[1959.277]: master offset 8180 s0 freq +0 path delay -1050 ptp4l[1960.277]: master offset 12329 s0 freq +0 path delay -1271 Using the nullf servo with the patch ------------------------------------ ptp4l[11138.115]: selected /dev/ptp1 as PTP clock ptp4l[11138.116]: port 1 (eth2): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[11138.116]: port 0 (/var/run/ptp4l): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[11138.117]: port 0 (/var/run/ptp4lro): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[11139.453]: port 1 (eth2): new foreign master 0c42a1.fffe.d1d084-1 ptp4l[11143.453]: selected best master clock 0c42a1.fffe.d1d084 ptp4l[11143.453]: port 1 (eth2): LISTENING to UNCALIBRATED on RS_SLAVE ptp4l[11145.452]: master offset 1556400 s1 freq +0 path delay -722 ptp4l[11146.453]: master offset -59008 s3 freq +0 path delay -722 ptp4l[11146.453]: port 1 (eth2): UNCALIBRATED to SLAVE on MASTER_CLOCK_SELECTED ptp4l[11147.454]: master offset 23604 s3 freq +0 path delay -16654 ptp4l[11148.454]: master offset -11480 s3 freq +0 path delay -722 ptp4l[11149.454]: master offset 7411 s3 freq +0 path delay -4053 ptp4l[11150.454]: master offset 664 s3 freq +0 path delay -722 ptp4l[11151.454]: master offset 4213 s3 freq +0 path delay -1011 ptp4l[11152.454]: master offset 3656 s3 freq +0 path delay -722 ptp4l[11153.454]: master offset 2691 s3 freq +0 path delay 531 ptp4l[11154.454]: master offset 3556 s3 freq +0 path delay 910 ptp4l[11155.454]: master offset 3940 s3 freq +0 path delay 910 ptp4l[11156.454]: master offset 3528 s3 freq +0 path delay 1322 ptp4l[11157.454]: master offset 3952 s3 freq +0 path delay 1322 ptp4l[11158.454]: master offset 3511 s3 freq +0 path delay 1759 ptp4l[11159.454]: master offset 3947 s3 freq +0 path delay 1759 ptp4l[11160.454]: master offset 3894 s3 freq +0 path delay 1804 ptp4l[11161.454]: master offset 3987 s3 freq +0 path delay 1759 ptp4l[11162.455]: master offset 3955 s3 freq +0 path delay 1759 ptp4l[11163.454]: master offset 3976 s3 freq +0 path delay 1722 ptp4l[11164.455]: master offset 3911 s3 freq +0 path delay 1759 ptp4l[11165.455]: master offset 3972 s3 freq +0 path delay 1722 ptp4l[11166.455]: master offset 3944 s3 freq +0 path delay 1722 ptp4l[11167.455]: master offset 4356 s3 freq +0 path delay 1310 ptp4l[11168.455]: master offset 3955 s3 freq +0 path delay 1295 ptp4l[11169.455]: master offset 3943 s3 freq +0 path delay 1295 ptp4l[11170.455]: master offset 4410 s3 freq +0 path delay 832 ptp4l[11171.455]: master offset 3942 s3 freq +0 path delay 832 ptp4l[11172.455]: master offset 3942 s3 freq +0 path delay 832 ptp4l[11173.455]: master offset 3876 s3 freq +0 path delay 906 ptp4l[11174.455]: master offset 3932 s3 freq +0 path delay 906 ptp4l[11175.455]: master offset 3948 s3 freq +0 path delay 906 ptp4l[11176.455]: master offset 3880 s3 freq +0 path delay 962 ptp4l[11177.455]: master offset 3948 s3 freq +0 path delay 962 ptp4l[11178.455]: master offset 3952 s3 freq +0 path delay 962 ptp4l[11179.455]: master offset 3994 s3 freq +0 path delay 908 ptp4l[11180.455]: master offset 3946 s3 freq +0 path delay 908 ptp4l[11181.455]: master offset 3967 s3 freq +0 path delay 883 ptp4l[11182.456]: master offset 3943 s3 freq +0 path delay 883 ptp4l[11183.455]: master offset 3926 s3 freq +0 path delay 908 ptp4l[11184.456]: master offset 3912 s3 freq +0 path delay 938 ptp4l[11185.456]: master offset 3940 s3 freq +0 path delay 938 ptp4l[11186.456]: master offset 3938 s3 freq +0 path delay 956 ptp4l[11187.456]: master offset 3842 s3 freq +0 path delay 1064 ptp4l[11188.456]: master offset 4050 s3 freq +0 path delay 956 ptp4l[11189.456]: master offset 3781 s3 freq +0 path delay 1121 ptp4l[11190.456]: master offset 3941 s3 freq +0 path delay 1121 ptp4l[11191.456]: master offset 3949 s3 freq +0 path delay 1121 ptp4l[11192.456]: master offset 3816 s3 freq +0 path delay 1250 -- Rahul Rameshbabu Rahul Rameshbabu <rrameshb...@nvidia.com> writes: > In the upstream linuxptp tree, the nullf servo has no way to transition to > the SERVO_LOCKED state except when the offset is zero. Transitioning to the > SERVO_LOCKED state is important for a servo that makes no frequency > adjustments because SERVO_LOCKED_STABLE is the only state that invokes > write_phase_mode, a performant way of adjusting the clock offset. The goal > of this change is to make it simple to configure entering the > SERVO_LOCKED_STABLE state by setting the offset_threshold when using the > nullf servo. In cases where the offset_threshold is not set but the > step_threshold is, the SERVO_LOCKED state is entered when the offset is > within the step_threshold. > > Signed-off-by: Rahul Rameshbabu <rrameshb...@nvidia.com> > > Rahul Rameshbabu (2): > Improve efficiency of nullf servo synchronization > Fix SERVO_JUMP docstring comment > > nullf.c | 9 ++++++--- > phc2sys.8 | 12 ++++++------ > ptp4l.8 | 14 +++++++------- > servo.h | 2 +- > ts2phc.8 | 8 ++++---- > 5 files changed, 24 insertions(+), 21 deletions(-) _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
