52 lines
1.9 KiB
Markdown
52 lines
1.9 KiB
Markdown
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# Raising Message Queue Size Limit
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The FSFW requires a higher message queue maximum lenght than the regular
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value configured for Linux. Failure to adjust this limit will cause
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errors when running FSFW applications.
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The following steps raise the maximum allowed message queue length to a higher
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number permanently, which is required for some framework components. The recommended
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values for the new message length is 130.
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2. Edit the /etc/sysctl.conf file
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```sh
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sudo nano /etc/sysctl.conf
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```
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Append at end:
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```sh
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fs/mqueue/msg_max = <newMsgMaxLen>
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```
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Apply changes with:
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```sh
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sudo sysctl -p
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```
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A possible solution which only persists for the current session is
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```sh
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echo <newMsgMax> | sudo tee /proc/sys/fs/mqueue/msg_max
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```
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# Setting up UNIX environment for real-time functionalities
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Please note that on most UNIX environments (e.g. Ubuntu), the real time functionalities
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used by the UNIX pthread module are restricted, which will lead to permission errors when creating these tasks
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and configuring real-time properites like scheduling priorities.
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If you use the real time scheduler in Linux, perform the following steps:
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Edit the /etc/security/limits.conf file and add following lines at the end:
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```sh
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<username> hard rtprio 99
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<username> soft rtprio 99
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```
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The soft limit can also be set in the console with `ulimit -Sr` if the hard
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limit has been increased, but it is recommended to add it to the file as well
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for convenience. If adding the second line is not desired for security reasons,
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the soft limit needs to be set for each session. If using an IDE like eclipse
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in that case, the IDE needs to be started from the console after setting
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the soft limit higher there. After adding the two lines to the file,
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the computer needs to be restarted.
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It is also recommended to perform the following change so that the unlockRealtime
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script does not need to be run anymore each time.
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