lazy Scheduling Context rebind + improve tool <-> monitor ABI#439
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dreamliner787-9 wants to merge 1 commit intoseL4:mainfrom
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lazy Scheduling Context rebind + improve tool <-> monitor ABI#439dreamliner787-9 wants to merge 1 commit intoseL4:mainfrom
dreamliner787-9 wants to merge 1 commit intoseL4:mainfrom
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Signed-off-by: Bill Nguyen <bill.nguyen@unsw.edu.au>
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Indanz
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Mar 16, 2026
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First, this really should be two separate commits, not lumped together like this.
Secondly, I'm missing creating a notifications object for passive servers that don't otherwise have one already, and binding the SC to the notification object if the PD is passive.
That last thing is really the only change you need compared to active PDs for setup.
Only other change needed is that you bind the SC when restarting the task, but I don't think Microkit does that yet, but rust-sel4 does I think.
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| /* If there are passive PDs in the system, lazily rebind it's Scheduling Context and resume TCB. | ||
| * To workaround https://github.com/seL4/seL4/issues/1617 by applying https://github.com/seL4/seL4/pull/523 | ||
| */ | ||
| for (unsigned idx = 0; idx < pd_metadata_len; idx++) { | ||
| if (pd_metadata[idx].passive) { | ||
| seL4_Error err = seL4_SchedContext_Bind(BASE_SCHED_CONTEXT_CAP + idx, BASE_NOTIFICATION_CAP + idx); | ||
| if (err != seL4_NoError) { | ||
| puts("MON|ERROR: could not bind scheduling context to notification object\n"); | ||
| continue; | ||
| } | ||
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| err = seL4_TCB_Resume(BASE_PD_TCB_CAP + idx); | ||
| if (err != seL4_NoError) { | ||
| puts("MON|ERROR: could not bind resume passive PD TCB\n"); | ||
| continue; | ||
| } | ||
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| puts("MON|INFO: PD '"); | ||
| puts(pd_metadata[idx].name); | ||
| puts("' is now passive!\n"); | ||
| } | ||
| } | ||
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There is no need to do this resume and you can bind the SC to the notification when you create the notification for a passive thread. This feels like the wrong place for that.
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| // Passive PDs are resumed by the Monitor | ||
| pd_tcb.extra.resume = !pd.passive; |
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Applied seL4/seL4#523 to workaround seL4/seL4#1617, and improved tool <-> monitor ABI by creating a metadata struct per PD, rather than adding a new symbol for every type of metadata.