Check CPU pinning #3071
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Check CPU pinning #3071
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meisterT
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Sep 3, 2025
| // Wait for all our children | ||
| do { | ||
| pid_t pid; | ||
| int status; |
| int status; | ||
| pid = wait(&status); | ||
| if ( pid==-1 ) { | ||
| if ( errno==ECHILD) { |
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(or remove spaces around conditions alltogether)
Ideally we should check that the submission is pinned to the CPU core that we set, but that information is not as easily available.
Those should be equivalent, just have different type.
When you try to pin a cgroup to a CPU that is offline, then the call to cgroups works fine, but then the Linux kernel just schedules the processes in that cgroup on any available CPU. That's definitely not what we want, so explicitly check and error out when the requested CPUs are not online.
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Check CPU pinning only on online CPUs in runguard and add a test source to make sure that submissions get scheduled on a single CPU. And some small tweaks/cleanups.