On Tue, 13 Aug 2019, 23:39 Dario Faggioli, <dfaggi...@suse.com> wrote:
> On Tue, 2019-08-13 at 19:43 +0100, Julien Grall wrote: > > On 8/13/19 6:34 PM, Dario Faggioli wrote: > > > On Tue, 2019-08-13 at 17:52 +0100, Julien Grall wrote: > > > > > > > So, unless the flag gets cleared again, or something else happens > > > that > > > makes the vCPU(s) fail the vcpu_runnable() check in > > > domain_unpause()->vcpu_wake(), I don't see why the wakeup that let > > > the > > > null scheduler start scheduling the vCPU doesn't happen... as it > > > instead does on x86 or !dom0less ARM (because, as far as I've > > > understood, it's only dom0less that doesn't work, it this correct?) > > > > Yes, I quickly tried to use NULL scheduler with just dom0 and it > > boots. > > > Ok. > > > Interestingly, I can't see the log: > > > > (XEN) Freed 328kB init memory. > > > > This is called as part of init_done before CPU0 goes into the idle > > loop. > > > > Adding more debug, it is getting stuck when calling > > domain_unpause_by_controller for dom0. Specifically vcpu_wake on > > dom0v0. > > > Wait... Is this also with just dom0, or when trying dom0less with some > domUs? > Dom0 is unpaused after all the domUs. In other words, the scheduler will see domUs first. > > The loop to assign a pCPU in null_vcpu_wake() is turning into an > > infinite loop. Indeed the loop is trying to pick CPU0 for dom0v0 that > > is > > already used by dom1v0. So the problem is in pick_cpu() or the data > > used > > by it. > > > Ah, interesting... > > > It feels to me this is an affinity problem. Note that I didn't > > request > > to pin dom0 vCPUs. > > > Yep, looking better, I think I've seen something suspicious now. I'll > send another debug patch. > You may want to see my last e-mail first just in case it rings a bell. :) I did more debugging during the evening. Cheers, > Regards > -- > Dario Faggioli, Ph.D > http://about.me/dario.faggioli > Virtualization Software Engineer > SUSE Labs, SUSE https://www.suse.com/ > ------------------------------------------------------------------- > <<This happens because _I_ choose it to happen!>> (Raistlin Majere) > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xenproject.org > https://lists.xenproject.org/mailman/listinfo/xen-devel
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