On 1/10/2026 2:33 PM, Manuel Bouyer wrote:
And this assembly work may have allowed me to find the problem. Basically, the CLI and STI macros are not atomic on Xen PV, and if preemption happens at a bad time we may end up updating the upcall_mask of our previous CPU. The attached patch should close this race condition; hopefully it's the last one.
I can confirm that, at least in my case, this allows me to build continuously all day without a crash.
Thanks! Konrad Schroder perseant%hhhh.org@localhost