[PATCH i-g-t v8] igt-runner fact checking

[Zbigniew Kempczyński]

On Thu, Nov 21, 2024 at 03:22:30PM +0100, Peter Senna Tschudin wrote:
> When using igt-runner, collect facts before each test and after the
> last test, and report when facts change. The facts are:
>  - GPUs on PCI bus: hardware.pci.gpu_at_addr.0000:03:00.0: 8086:e20b Intel Battlemage (Gen20)
>  - Associations between PCI GPU and DRM card: hardware.pci.drm_card_at_addr.0000:03:00.0: card1
>  - Kernel taints: kernel.is_tainted.taint_warn: true
>  - GPU kernel modules loaded: kernel.kmod_is_loaded.i915: true
> 
> This change imposes little execution overhead and adds just a few
> lines of logging. The facts will be printed on normal igt-runner
> output. Here is a real example from our CI shwoing
> hotreplug-lateclose changing the DRM card number and tainting the
> kernel on the abort path:
> 
>  [245.316207] [056/121] (816s left) core_hotunplug (hotreplug-lateclose)
>  [245.383596] Starting subtest: hotreplug-lateclose
>  [249.843361] Aborting: Lockdep not active
>  [249.858249] [FACT core_hotunplug (hotreplug-lateclose)] changed: hardware.pci.drm_card_at_addr.0000:00:02.0: card0 -> card1
>  [249.858392] [FACT core_hotunplug (hotreplug-lateclose)] new: kernel.is_tainted.taint_die: true
>  [249.859075] Closing watchdogs

<cut>

Regardless implementation - I wondered a bit about igt_runner and using
it by the others - instead of turning on gathering the facts from the
default I would add separate option to enable it. I see -f/--facts would
appropriate. This would allow to enable/disable it from CI perspective
if we would notice some problems - instead reverting the code we can
just disable it from CI perspective.

--
Zbigniew