On Jun 23, 2020, at 6:13 PM, Daniel Vetter daniel@ffwll.ch wrote:
Ok I tested this. I can't use your script to repro because
- I don't have a setup with xfs, and the splat points at an issue in xfs
- reproducing lockdep splats in shrinker callbacks is always a bit tricky
What’s xfs setup are you talking about? This is simple xfs rootfs and then trigger swapping. Nothing tricky here as it hit on multiple machines within a few seconds on linux-next.
Summary: Everything is working as expected, there's no change in the lockdep annotations. I really think the problem is that either your testcase doesn't hit the issue reliably enough, or that you're not actually testing the same kernels and there's some other changes (xfs most likely, but really it could be anywhere) which is causing this regression. I'm rather convinced now after this test that it's not my stuff.
Well, the memory pressure workloads have been running for years on daily linux-next builds and never saw this one happened once. Also, the reverting is ONLY to revert your patch on the top of linux-next will stop the splat, so there is no not testing the same kernel at all.