On Wed, 24 Nov 2021 18:20:40 +0100 Stefan Dietrich wrote: > Hi all, > > six exciting hours and a lot of learning later, here it is. > Symptomatically, the critical commit appears for me between 5.14.21- > 051421-generic and 5.15.0-051500rc2-generic - I did not find an amd64 > build for rc1. > > Please see the git-bisect output below and let me know how I may > further assist in debugging! Well, let's CC those involved, shall we? :) Thanks for working thru the bisection! > a90ec84837325df4b9a6798c2cc0df202b5680bd is the first bad commit > commit a90ec84837325df4b9a6798c2cc0df202b5680bd > Author: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx> > Date: Mon Jul 26 20:36:57 2021 -0700 > > igc: Add support for PTP getcrosststamp() > > i225 supports PCIe Precision Time Measurement (PTM), allowing us to > support the PTP_SYS_OFFSET_PRECISE ioctl() in the driver via the > getcrosststamp() function. > > The easiest way to expose the PTM registers would be to configure > the PTM > dialogs to run periodically, but the PTP_SYS_OFFSET_PRECISE ioctl() > semantics are more aligned to using a kind of "one-shot" way of > retrieving > the PTM timestamps. But this causes a bit more code to be written: > the > trigger registers for the PTM dialogs are not cleared > automatically. > > i225 can be configured to send "fake" packets with the PTM > information, adding support for handling these types of packets is > left for the future. > > PTM improves the accuracy of time synchronization, for example, > using > phc2sys, while a simple application is sending packets as fast as > possible. First, without .getcrosststamp(): > > phc2sys[191.382]: enp4s0 sys offset -959 s2 freq -454 > delay 4492 > phc2sys[191.482]: enp4s0 sys offset 798 s2 freq +1015 > delay 4069 > phc2sys[191.583]: enp4s0 sys offset 962 s2 freq +1418 > delay 3849 > phc2sys[191.683]: enp4s0 sys offset 924 s2 freq +1669 > delay 3753 > phc2sys[191.783]: enp4s0 sys offset 664 s2 freq +1686 > delay 3349 > phc2sys[191.883]: enp4s0 sys offset 218 s2 freq +1439 > delay 2585 > phc2sys[191.983]: enp4s0 sys offset 761 s2 freq +2048 > delay 3750 > phc2sys[192.083]: enp4s0 sys offset 756 s2 freq +2271 > delay 4061 > phc2sys[192.183]: enp4s0 sys offset 809 s2 freq +2551 > delay 4384 > phc2sys[192.283]: enp4s0 sys offset -108 s2 freq +1877 > delay 2480 > phc2sys[192.383]: enp4s0 sys offset -1145 s2 freq +807 > delay 4438 > phc2sys[192.484]: enp4s0 sys offset 571 s2 freq +2180 > delay 3849 > phc2sys[192.584]: enp4s0 sys offset 241 s2 freq +2021 > delay 3389 > phc2sys[192.684]: enp4s0 sys offset 405 s2 freq +2257 > delay 3829 > phc2sys[192.784]: enp4s0 sys offset 17 s2 freq +1991 > delay 3273 > phc2sys[192.884]: enp4s0 sys offset 152 s2 freq +2131 > delay 3948 > phc2sys[192.984]: enp4s0 sys offset -187 s2 freq +1837 > delay 3162 > phc2sys[193.084]: enp4s0 sys offset -1595 s2 freq +373 > delay 4557 > phc2sys[193.184]: enp4s0 sys offset 107 s2 freq +1597 > delay 3740 > phc2sys[193.284]: enp4s0 sys offset 199 s2 freq +1721 > delay 4010 > phc2sys[193.385]: enp4s0 sys offset -169 s2 freq +1413 > delay 3701 > phc2sys[193.485]: enp4s0 sys offset -47 s2 freq +1484 > delay 3581 > phc2sys[193.585]: enp4s0 sys offset -65 s2 freq +1452 > delay 3778 > phc2sys[193.685]: enp4s0 sys offset 95 s2 freq +1592 > delay 3888 > phc2sys[193.785]: enp4s0 sys offset 206 s2 freq +1732 > delay 4445 > phc2sys[193.885]: enp4s0 sys offset -652 s2 freq +936 > delay 2521 > phc2sys[193.985]: enp4s0 sys offset -203 s2 freq +1189 > delay 3391 > phc2sys[194.085]: enp4s0 sys offset -376 s2 freq +955 > delay 2951 > phc2sys[194.185]: enp4s0 sys offset -134 s2 freq +1084 > delay 3330 > phc2sys[194.285]: enp4s0 sys offset -22 s2 freq +1156 > delay 3479 > phc2sys[194.386]: enp4s0 sys offset 32 s2 freq +1204 > delay 3602 > phc2sys[194.486]: enp4s0 sys offset 122 s2 freq +1303 > delay 3731 > > Statistics for this run (total of 2179 lines), in nanoseconds: > average: -1.12 > stdev: 634.80 > max: 1551 > min: -2215 > > With .getcrosststamp() via PCIe PTM: > > phc2sys[367.859]: enp4s0 sys offset 6 s2 freq +1727 > delay 0 > phc2sys[367.959]: enp4s0 sys offset -2 s2 freq +1721 > delay 0 > phc2sys[368.059]: enp4s0 sys offset 5 s2 freq +1727 > delay 0 > phc2sys[368.160]: enp4s0 sys offset -1 s2 freq +1723 > delay 0 > phc2sys[368.260]: enp4s0 sys offset -4 s2 freq +1719 > delay 0 > phc2sys[368.360]: enp4s0 sys offset -5 s2 freq +1717 > delay 0 > phc2sys[368.460]: enp4s0 sys offset 1 s2 freq +1722 > delay 0 > phc2sys[368.560]: enp4s0 sys offset -3 s2 freq +1718 > delay 0 > phc2sys[368.660]: enp4s0 sys offset 5 s2 freq +1725 > delay 0 > phc2sys[368.760]: enp4s0 sys offset -1 s2 freq +1721 > delay 0 > phc2sys[368.860]: enp4s0 sys offset 0 s2 freq +1721 > delay 0 > phc2sys[368.960]: enp4s0 sys offset 0 s2 freq +1721 > delay 0 > phc2sys[369.061]: enp4s0 sys offset 4 s2 freq +1725 > delay 0 > phc2sys[369.161]: enp4s0 sys offset 1 s2 freq +1724 > delay 0 > phc2sys[369.261]: enp4s0 sys offset 4 s2 freq +1727 > delay 0 > phc2sys[369.361]: enp4s0 sys offset 8 s2 freq +1732 > delay 0 > phc2sys[369.461]: enp4s0 sys offset 7 s2 freq +1733 > delay 0 > phc2sys[369.561]: enp4s0 sys offset 4 s2 freq +1733 > delay 0 > phc2sys[369.661]: enp4s0 sys offset 1 s2 freq +1731 > delay 0 > phc2sys[369.761]: enp4s0 sys offset 1 s2 freq +1731 > delay 0 > phc2sys[369.861]: enp4s0 sys offset -5 s2 freq +1725 > delay 0 > phc2sys[369.961]: enp4s0 sys offset -4 s2 freq +1725 > delay 0 > phc2sys[370.062]: enp4s0 sys offset 2 s2 freq +1730 > delay 0 > phc2sys[370.162]: enp4s0 sys offset -7 s2 freq +1721 > delay 0 > phc2sys[370.262]: enp4s0 sys offset -3 s2 freq +1723 > delay 0 > phc2sys[370.362]: enp4s0 sys offset 1 s2 freq +1726 > delay 0 > phc2sys[370.462]: enp4s0 sys offset -3 s2 freq +1723 > delay 0 > phc2sys[370.562]: enp4s0 sys offset -1 s2 freq +1724 > delay 0 > phc2sys[370.662]: enp4s0 sys offset -4 s2 freq +1720 > delay 0 > phc2sys[370.762]: enp4s0 sys offset -7 s2 freq +1716 > delay 0 > phc2sys[370.862]: enp4s0 sys offset -2 s2 freq +1719 > delay 0 > > Statistics for this run (total of 2179 lines), in nanoseconds: > average: 0.14 > stdev: 5.03 > max: 48 > min: -27 > > For reference, the statistics for runs without PCIe congestion show > that the improvements from enabling PTM are less dramatic. For two > runs of 16466 entries: > without PTM: avg -0.04 stdev 10.57 max 39 min -42 > with PTM: avg 0.01 stdev 4.20 max 19 min -16 > > One possible explanation is that when PTM is not enabled, and > there's a lot > of traffic in the PCIe fabric, some register reads will take more > time > than the others because of congestion on the PCIe fabric. > > When PTM is enabled, even if the PTM dialogs take more time to > complete under heavy traffic, the time measurements do not depend > on > the time to read the registers. > > This was implemented following the i225 EAS version 0.993. > > Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx> > Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@xxxxxxxxxxxxxxx> > Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> > > drivers/net/ethernet/intel/igc/igc.h | 1 + > drivers/net/ethernet/intel/igc/igc_defines.h | 31 +++++ > drivers/net/ethernet/intel/igc/igc_ptp.c | 179 > +++++++++++++++++++++++++++ > drivers/net/ethernet/intel/igc/igc_regs.h | 23 ++++ > 4 files changed, 234 insertions(+) > > > On Wed, 2021-11-24 at 08:33 +0100, Greg KH wrote: > > On Wed, Nov 24, 2021 at 08:28:39AM +0100, Stefan Dietrich wrote: > > > Summary: When attempting to rise or shut down a NIC manually or via > > > network-manager under 5.15, the machine reboots or freezes. > > > > > > Occurs with: 5.15.4-051504-generic and earlier 5.15 mainline ( > > > https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.15.4/) as well as > > > liquorix flavours. > > > Does not occur with: 5.14 and 5.13 (both with various flavours) > > > > Can you use 'git bisect' between 5.14 and 5.15 to find the problem > > commit? > > > > thanks, > > > > greg k-h >
