Dear Zhou
On 2021-03-11 12:48, zy wrote:
Dear Mr. Hacker,
Thank you for your reply. I package the operation of creating real-time
xenomai ethercat thread and slave configuration into a dynamic library
and call it to start ethercat communication in my Qt GUI process. But,
I am not familiar with Xenomai, but I know that you cannot run an
application where real time and memory allocation appears in the same
process. Page allocation can never happen in real time, unless your
environment preallocates enough memory that you will ever use.
Note that threads run in the same process, so it doesn't help to do the
GUI in a separate thread. It must be another process.
The way I do it (in pdserv) is to have the real time process fork()ing
off a GUI process, with shared memory between them to communicate. This
is quite a difficult thing to get right, but then I can use whatever I
need in the GUI task (memory allocation, file operations) without the
real time task blocking.
increases. The xenomai page fault and the big latency of calling
ecrt_master_receive seems occurs at the same time.
One thing I have noticed is that Intel network chipsets are not well
behaved in real time. They tend to keep back packets. I noticed it on my
Intel I219-V, so that might also be a cause.
Richard
Do you mean I should create a new process in GUI and call my dynamic
library to start the real-time ethercat thread in the new process
instead of
in GUI process ? Is my understanding correct ?
Best regards,
Zhou Yang
------------------ 原始邮件 ------------------
*发件人:* "Richard Hacker" <[email protected]>;
*发送时间:* 2021年3月11日(星期四) 晚上6:06
*收件人:* "etherlab-users"<[email protected]>;
*抄送:* "zy"<[email protected]>;
*主题:* Re: [Etherlab-users] ecrt_master_receive big latency
Dear Zhou
On 2021-03-11 08:15, zy wrote:
> page fault. I alse execute “cat /proc/xenomai/stat” and find MSW of the
Page faults and real time execution will never become friends. Running a
user space application like Qt together with a real time thread in the
same process almost certainly leads to problems. You need to separate it
out into a process running your GUI and another running in real-time,
with mlockall() and the works.
Mit freundlichem Gruß
Richard Hacker
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Richard Hacker M.Sc.
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------------------------------------------------------------------------
Mit freundlichem Gruß
Richard Hacker
--
------------------------------------------------------------------------
Richard Hacker M.Sc.
[email protected]
Tel.: +49 201 / 36014-16
Ingenieurgemeinschaft IgH
Gesellschaft für Ingenieurleistungen mbH
Nordsternstraße 66
D-45329 Essen
Amtsgericht Essen HRB 11500
USt-Id.-Nr.: DE 174 626 722
Geschäftsführung:
- Dr.-Ing. Siegfried Rotthäuser
- Dr. Sven Beermann, Prokurist
Tel.: +49 201 / 360-14-0
http://www.igh.de
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