The real realtime preemption end game

Posted Nov 19, 2023 9:40 UTC (Sun) by DemiMarie (subscriber, #164188)
In reply to: The real realtime preemption end game by mjg59
Parent article: The real realtime preemption end game

In my expierience, pstore is the only reliable way to get a stack trace on panic, unless one is in a VM. Serial consoles don’t work because end-user systems don’t have them. Graphical consoles don’t work because the user is in an X11 or Wayland session.

How does Windows manage to display the BSOD message?

The real realtime preemption end game

Posted Nov 19, 2023 14:10 UTC (Sun) by Wol (subscriber, #4433) [Link]

> How does Windows manage to display the BSOD message?

I guess it just seizes control of the graphics card, or puts it into text mode, or whatever.

Cheers,
Wol

The real realtime preemption end game

Posted Nov 19, 2023 20:38 UTC (Sun) by ballombe (subscriber, #9523) [Link]

It displays the BSOD at start up, and then prints the normal screen as an overlay on top of it. This way, when something goes wrong, the overlay disappears and you see the BSOD. That is why the option "customize the BSOD" requires you to reboot. That is also why, if you set the background to an image with transparency, you get the BSOD.

(just jocking of course)

The real realtime preemption end game

Posted Nov 19, 2023 21:07 UTC (Sun) by Cyberax (✭ supporter ✭, #52523) [Link] (1 responses)

> How does Windows manage to display the BSOD message?

Windows drivers are much more resilient than the drivers in Linux. A surprising amount of functionality remains working in Windows even if half the kernel is going haywire.

In particular, modesetting and simple framebuffer access have always been a part of the kernel driver. And each driver is also responsible for pre-allocating its object pools, so there's much less dependency on memory allocation. The IRQL system also has a side effect of forcing driver writers to avoid putting anything too involved inside the critical pathways.

The real realtime preemption end game

Posted Dec 8, 2023 17:45 UTC (Fri) by pawel44 (guest, #162008) [Link]

Wishful thinking. USB driver failure will bring Windows down. Not to mention Windows Driver Model and Windows Driver Frameworks are holey like Swiss cheese.