Hello, I am reconnecting the ML.
I am not aware of any good documentation for SCHED_TP, but there is an example in smokey/sched-tp which Id use as starting point. I don’t think SCHED_TP will measurable affect latency, outside of course in the case where its “by design” (process needs to wait for its timeslice). Norbert From: 孙世龙 sunshilong <sunshilong...@gmail.com> Sent: Samstag, 18. Juli 2020 07:51 To: Lange Norbert <norbert.la...@andritz.com> Cc: Meng, Fino <fino.m...@intel.com> Subject: Re: Are there some methods that could limit how much CPU resources could be a single Xenomai process or thread? Hi, Norbert Thank you for the clarification. >You can do something similar with the temporal partitioning scheduler >(SCHED_TP), >cgroups uses a similar concept of "time-slices", but is less strict AFAIU Does SCHED_TP enlarge the latency(compared to SCHED_FIFO)? Do you have more information about SCHED_TP? If the answer is yes, could you please suggest some documents for me to go through? I searched all the source code of the Xenomai project and checked the help information from the Kconfig, but no useful information about SCHED_TP was found. I googled it, only found this: The SCHED_TP policy divides the scheduling time into a recurring global frame, which is itself divided into an arbitrary number of time partitions. Only threads assigned to the current partition are deemed runnable, and scheduled according to a FIFO-based rule within this partition. When completed, the current partition is advanced automatically to the next one by the scheduler, and the global time frame recurs from the first partition defined, when the last partition has ended. Thank you for your attention to this matter. Best Regards. Sunshilong(孙世龙) On Fri, Jul 17, 2020 at 6:44 PM Lange Norbert <norbert.la...@andritz.com<mailto:norbert.la...@andritz.com>> wrote: > -----Original Message----- > From: Xenomai > <xenomai-boun...@xenomai.org<mailto:xenomai-boun...@xenomai.org>> On Behalf > Of ??? > sunshilong via Xenomai > Sent: Freitag, 17. Juli 2020 12:18 > To: Meng, Fino <fino.m...@intel.com<mailto:fino.m...@intel.com>> > Cc: Xenomai (xenomai@xenomai.org<mailto:xenomai@xenomai.org>) > <xenomai@xenomai.org<mailto:xenomai@xenomai.org>> > Subject: Re: Are there some methods that could limit how much CPU > resources could be a single Xenomai process or thread? > > NON-ANDRITZ SOURCE: BE CAUTIOUS WITH CONTENT, LINKS OR > ATTACHMENTS. > > > Hi, 孟祥夫 > Thank you for taking the time to respond to my question. > > >In my understanding cgroup's design is exclusionary with real- > time/deterministic/time coordinate design. > >The latency/jitter is already down to 20us level, how it can endure cgroup's > volatility. > I don't hold much hope, either. But I am not sure whether it's impossible to > achieve this goal or not. You can do something similar with the temporal partitioning scheduler (SCHED_TP), cgroups uses a similar concept of "time-slices", but is less strict AFAIU Norbert ________________________________ This message and any attachments are solely for the use of the intended recipients. They may contain privileged and/or confidential information or other information protected from disclosure. If you are not an intended recipient, you are hereby notified that you received this email in error and that any review, dissemination, distribution or copying of this email and any attachment is strictly prohibited. If you have received this email in error, please contact the sender and delete the message and any attachment from your system. ANDRITZ HYDRO GmbH Rechtsform/ Legal form: Gesellschaft mit beschränkter Haftung / Corporation Firmensitz/ Registered seat: Wien Firmenbuchgericht/ Court of registry: Handelsgericht Wien Firmenbuchnummer/ Company registration: FN 61833 g DVR: 0605077 UID-Nr.: ATU14756806 Thank You ________________________________ ________________________________ This message and any attachments are solely for the use of the intended recipients. They may contain privileged and/or confidential information or other information protected from disclosure. If you are not an intended recipient, you are hereby notified that you received this email in error and that any review, dissemination, distribution or copying of this email and any attachment is strictly prohibited. If you have received this email in error, please contact the sender and delete the message and any attachment from your system. ANDRITZ HYDRO GmbH Rechtsform/ Legal form: Gesellschaft mit beschränkter Haftung / Corporation Firmensitz/ Registered seat: Wien Firmenbuchgericht/ Court of registry: Handelsgericht Wien Firmenbuchnummer/ Company registration: FN 61833 g DVR: 0605077 UID-Nr.: ATU14756806 Thank You ________________________________
