Re: [Linuxptp-users] [issue] phc2sys results large jitter with multiple '-c'

2023-06-21 Thread Keller, Jacob E
> -Original Message- > From: Miroslav Lichvar > Sent: Wednesday, June 21, 2023 12:52 AM > To: Keller, Jacob E > Cc: linuxptp-users@lists.sourceforge.net > Subject: Re: [Linuxptp-users] [issue] phc2sys results large jitter with > multiple '-c' > &g

Re: [Linuxptp-users] [issue] phc2sys results large jitter with multiple '-c'

2023-06-21 Thread Miroslav Lichvar
On Tue, Jun 20, 2023 at 10:07:14PM -0700, Jacob Keller wrote: > On 6/11/2023 11:53 PM, Miroslav Lichvar wrote: > > If you need to synchronize multiple PHCs to each other, it's better to > > use one phc2sys instance to synchronize the system clock to the source > > PHC and then another phc2sys insta

Re: [Linuxptp-users] [issue] phc2sys results large jitter with multiple '-c'

2023-06-20 Thread Jacob Keller
On 6/11/2023 11:53 PM, Miroslav Lichvar wrote: > On Mon, Jun 12, 2023 at 12:24:19PM +0800, egg car wrote: >> 5) not only the 4 ports on the same nic, any combination of ptp0~ptp9 results >> the same. >> >> >> Have gone through the phc2sys codes, find nothing reasonable that explains >> this issu

Re: [Linuxptp-users] [issue] phc2sys results large jitter with multiple '-c'

2023-06-12 Thread egg car
Dear Miro, > Yes, it's related to PCIe delays. The problem is that the kernel > doesn't provide an ioctl to measure offset between two PHCs, so > phc2sys has to do it in user space using clock_gettime(), which > doesn't work very well (large delay, jitter and asymmetry). Yes it seems like the clo

Re: [Linuxptp-users] [issue] phc2sys results large jitter with multiple '-c'

2023-06-11 Thread Miroslav Lichvar
On Mon, Jun 12, 2023 at 12:24:19PM +0800, egg car wrote: > 5) not only the 4 ports on the same nic, any combination of ptp0~ptp9 results > the same. > > > Have gone through the phc2sys codes, find nothing reasonable that explains > this issue so far. > > I can see when the large jitter happens,

[Linuxptp-users] [issue] phc2sys results large jitter with multiple '-c'

2023-06-11 Thread egg car
Hi, Just upgraded to v4.0, and trying the new feature of 'phc2sys' with multiple '-c'. It seems not working very well on my test machine, with large offset jitters. Here's my configuration: 1) ptp0~ptp3 are 4 ports on a 4 port i350, ptp4~ptp9 are separated i210 ports. 2) run ts2phc on ptp3(enp