> -----Original Message----- > From: Jord Pool [mailto:jord.p...@outlook.com] > Sent: Friday, July 27, 2018 1:55 PM > To: Keller, Jacob E <jacob.e.kel...@intel.com>; Richard Cochran > <richardcoch...@gmail.com>; Cliff Spradlin via Linuxptp-users <linuxptp- > us...@lists.sourceforge.net> > Subject: Re: [Linuxptp-users] PXE Boot > > The driver in the PTP slave machine is the e1000e driver version 3.2.6k. I > have > updated this to version 3.4.2 but then it wouldn't even work anymore at all. >
Ok. Yea. I assume you used the sourceforge driver? Hmmm, yea, the 3.2.6-k has all the fixes I'm aware of for PTP. > I don't know for sure, but is it safe to assume this is due to heavy network > load or > would the problem be somewhere else? > Network load makes sense, since that could cause the device to take longer to transmit. I'm not sure if something like traffic classes could work to help ensure that PTP packets get higher priority or not.. (I don't even know if e1000e supports traffic classes offhand). > Could there be any possibility of prioritising PTP traffic at kernel level to > ensure > the PTP packets will be timestamped within the default of 1ms (or at least a > value > at which I can safely boot multiple other servers without interruption). > Maybe, but I'm not aware of how to do this. My best guess would be some sort of traffic class setup which puts the ptp4l socket at a higher priority than other traffic. I'm not really sure how to go about setting that up though. It likely needs hardware support so that the hardware knows to prioritise sending the PTP packets first. Thanks, Jake > Jord Pool > IT Service Management > > > ________________________________ > > From: Keller, Jacob E <jacob.e.kel...@intel.com> > Sent: Friday, July 27, 2018 10:25:06 PM > To: Jord Pool; Richard Cochran; Cliff Spradlin via Linuxptp-users > Subject: RE: [Linuxptp-users] PXE Boot > > > > > -----Original Message----- > > From: Jord Pool [mailto:jord.p...@outlook.com] > > Sent: Thursday, July 26, 2018 11:59 PM > > To: Richard Cochran <richardcoch...@gmail.com>; Cliff Spradlin via Linuxptp- > > users <linuxptp-users@lists.sourceforge.net> > > Subject: Re: [Linuxptp-users] PXE Boot > > > > Hi all! > > > > As I explained in my previous email, when PXE booting, the PXE boot server > that > > runs in slave mode will have it's PTP slave instance interrupted, unless I > > set the > > tx_timestamp_timeout to ~200ms. Now what happens when booting more > than > > four server at the same time via PXE boot? Will I then have to increase the > > tx_timestamp_timeout value again? This is not really the most practical way > > of > > being able for the PXE boot server (PTP Slave) to keep synchronised. > > > > To solve the problem above, maybe there is a way to prioritise the PTP > > network > > traffic so that it will not have any interference with servers booting > > through > PXE? > > > > Jord > > > > Hi Jord, > > The reason you need to increase the Tx timeout is that the driver you're > using is > taking too long to report the timestamp. It's almost certainly either a > driver/hardware limitation, or a bug in the driver. > > Basically, ptp4l is sending a Tx packet with a timestmap request, and waits > up to 1 > millisecond for a response. But you increased this limit ot have it wait 200 > milliseconds. This means that the driver is taking longer than 1 millisecond > to send > the packet, get the timestamp, and report it back... If it fails when the > timeout is > 200 milliseconds, then it's taking over 1/5th of a second to do this... > > What driver/hardware are you using? > > Thanks, > Jake > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
