Dear experts, I am wondering when checking a running seL4 target from GDB, how can we find all threads? It seems that `ksReadyQueues[]` only holds a sub set. Regards, yf
Hello Yanfeng, On 2024-11-24 08:06, Yanfeng via Devel wrote:
I am wondering when checking a running seL4 target from GDB, how can we find all threads?
There is no easy way.
It seems that `ksReadyQueues[]` only holds a sub set.
It only hold tasks that want to run now, but can't because there is another task running. MCS also has a refill queue which holds tasks that want to run, but can't because they ran out of budget for their period. But the main problem is that all tasks not running either are suspended or blocked and they are scattered around in different queues. They can block on endpoints, notifications or be waiting for a reply or a fault handler. Every endpoint and notification has its own queues. Suspended tasks are not in any queue at all. Assuming you allocated all TCB's caps sequentially in your initial task's root CNode, finding them through that might be the easiest way. Greetings, Indan
Hey Yanfeng and Indan, Assuming you're on debug mode, could you walk the ksDebugTCBs linked list? This is what seL4_DumpScheduler does, and from memory, this will print out all of the threads on a given core regardless of what state they are in. - Alwin ________________________________ From: Indan Zupancic <indan@nul.nu> Sent: Sunday, November 24, 2024 10:10 PM To: Yanfeng <yfliu2008@qq.com> Cc: devel@sel4.systems <devel@sel4.systems> Subject: [seL4] Re: find all seL4 threads Hello Yanfeng, On 2024-11-24 08:06, Yanfeng via Devel wrote:
I am wondering when checking a running seL4 target from GDB, how can we find all threads?
There is no easy way.
It seems that `ksReadyQueues[]` only holds a sub set.
It only hold tasks that want to run now, but can't because there is another task running. MCS also has a refill queue which holds tasks that want to run, but can't because they ran out of budget for their period. But the main problem is that all tasks not running either are suspended or blocked and they are scattered around in different queues. They can block on endpoints, notifications or be waiting for a reply or a fault handler. Every endpoint and notification has its own queues. Suspended tasks are not in any queue at all. Assuming you allocated all TCB's caps sequentially in your initial task's root CNode, finding them through that might be the easiest way. Greetings, Indan _______________________________________________ Devel mailing list -- devel@sel4.systems To unsubscribe send an email to devel-leave@sel4.systems
Alwin and Indan, Thank you very much for the information. Yes I can see `ksDebugTCBs` from GDB, I will try it. Regards, yf On Sun, 2024-11-24 at 19:32 +0000, Alwin Joshy via Devel wrote:
Hey Yanfeng and Indan,
Assuming you're on debug mode, could you walk the ksDebugTCBs linked list? This is what seL4_DumpScheduler does, and from memory, this will print out all of the threads on a given core regardless of what state they are in.
- Alwin
________________________________ From: Indan Zupancic <indan@nul.nu> Sent: Sunday, November 24, 2024 10:10 PM To: Yanfeng <yfliu2008@qq.com> Cc: devel@sel4.systems <devel@sel4.systems> Subject: [seL4] Re: find all seL4 threads
Hello Yanfeng,
On 2024-11-24 08:06, Yanfeng via Devel wrote:
I am wondering when checking a running seL4 target from GDB, how can we find all threads?
There is no easy way.
It seems that `ksReadyQueues[]` only holds a sub set.
It only hold tasks that want to run now, but can't because there is another task running.
MCS also has a refill queue which holds tasks that want to run, but can't because they ran out of budget for their period.
But the main problem is that all tasks not running either are suspended or blocked and they are scattered around in different queues. They can block on endpoints, notifications or be waiting for a reply or a fault handler.
Every endpoint and notification has its own queues. Suspended tasks are not in any queue at all.
Assuming you allocated all TCB's caps sequentially in your initial task's root CNode, finding them through that might be the easiest way.
Greetings,
Indan _______________________________________________ Devel mailing list -- devel@sel4.systems To unsubscribe send an email to devel-leave@sel4.systems _______________________________________________ Devel mailing list -- devel@sel4.systems To unsubscribe send an email to devel-leave@sel4.systems
participants (3)
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Alwin Joshy -
Indan Zupancic -
Yanfeng