l4-hackers November 2014

l4-hackers@os.inf.tu-dresden.de

13 participants
15 discussions

Re: Question about schedule policy
by Björn Döbel 05 Nov '14

05 Nov '14

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, On 05.11.2014 04:18, Kevin wrote: > Thanks for your answer, please always reply to the mailing list. The answers may also be interesting to other people. > Maybe my question is confused. I know the concept of class > "Thread",It'sa runnable, schedulable activity, and a Task has many > Threads, and Task is just some address spaces. > > So, my question is: If there are many Tasks, for example, Task A > and Task B, and I want each Thread of Task A has a higher priority > than B's, what should I do? Fiasco schedules threads in a priority-based, round-robin fashion. That means it always selects the thread with the highest priority (per CPU). If multiple threads with the same prio exist, they get equal shares of the CPU. You can set a thread's priority upon creation using the l4_scheduler_*() system calls. There are examples of that in l4/pkg/examples - grepping for 'scheduler_' should do the trick. Furthermore, you can also set the prio of threads within the Lua init scripts. For that purpose you do something like: loader:startv({ caps = ..., log = ..., scheduler = L4.Env.user_factory:create(L4.Proto.Scheduler, 0x90, 0x80) }, ...); This sets up a scheduler environment for your new program. The numeric parameters are max_prio and base_prio. When you later specify priorities using the scheduler interface in your program, the actual prio of your threads will be calculated: prio := base_prio + selected_prio; if (prio > max_prio) prio := max_prio; > anyway, can we schedule these Threads by group? not just set the > scheduling parameters of Thread one by one. You need to set the scheduling parameters for every newly created thread separately. If you use the pthread interface, this will be done by the library and all threads will have the same prio. In combination with the Lua scheduler settings this might be what you want. Bjoern -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlRZ61EACgkQP5ijxgQLUNn58ACfXN2gmSGxUMD602bB2h26mIbq VssAniec6EQs4q1VTo/0zVBj1mgQgm0Q =oY4R -----END PGP SIGNATURE-----

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Question about schedule policy
by Kevin 04 Nov '14

04 Nov '14

Hello, I know the class "Task" in fiasco is equaled with the word "Domain" in VMM, but I can't find some schedule policy about Task in fiasco, all I find is scheduling about Thread in class Context and sched_context. So, is there any schedule policy about Task? thanks, kevin

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is there a way to run the compiled arm on Nexus S ?
by cem akpolat 04 Nov '14

04 Nov '14

Dear all, I have compiled couple of days ago l4android for arm architecture, and now I want to boot it on Nexus S, however, I couldn't find a way to tun bootstrapLinuxAndroid.elf file on arm based architecture. I have already seen in some research papers (one of them is as follows). http://www.isti.tu-berlin.de/fileadmin/fg214/liebergeld/spsm03-lange.pdf How could be l4android booted on the Nexus S? Thanks, Best Regards, Cem Akpolat

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FOSDEM 2015 - CfP: Microkernels DevRoom
by Vasily A. Sartakov 01 Nov '14

01 Nov '14

Greetings. ---- FOSDEM 2015 - CfP: Microkernels DevRoom I would love to announce the Call for Participation in the FOSDEM'15 Microkernel DevRoom. FOSDEM’15 will be held at the ULB Campus Solbosch on Saturday 31 January and Sunday 1 February 2015 and Microkernel devroom is scheduled on Sunday (01 February). Topics accepted include, but are not limited to: * Kernels, environments and frameworks * Hardware support: architectures, drivers * Languages and tools * Use cases, experiences, lessons learned and demos * Technical challenges and issues * Testing and support * Community building. Please use Pentabarf [1] system to submit your proposals. You do not need to create new account if you already have one. If the password is lost you can recovery it. Moreover, we have the devroom mailing list [2] Within submission please provide: * Title of your talk * Abstract, one or two paragraphs * Information about speaker: Name, bio, photo * Length of the talk. Each talk is limited to 45 minutes but can be less. Important dates: * Nov 28: Deadline for submissions * Dec 01: Speakers notified of acceptance * Dec 08: Schedule published Please do not hesitate to forward this CfP to anyone interested in participating. 1. https://penta.fosdem.org/submission/FOSDEM15 2. https://lists.fosdem.org/listinfo/microkernel-devroom ---- -- Vasily A. Sartakov sartakov(a)ksyslabs.org

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Dummy irq
by teclis High Elf 01 Nov '14

01 Nov '14

If I wanted to create a dummy irq that didn't actually exist in hardware but I could use for asynchronous notification between processes or between a hypervisor and a VM how would I do that in L4Re? What would the dummy entry look like in the .devs file? thanks

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l4-hackers November 2014