On Mon, Mar 07, 2022 at 04:32:49PM +1100, Dave Chinner wrote: > Willy reported generic/530 had started hanging on his test machines > and I've tried to reproduce the problem he reported. While I haven't > reproduced the exact hang he's been having, I've found a couple of > others while running g/530 in a tight loop on a couple of test > machines. [...] > > Willy, can you see if these patches fix the problem you are seeing? > If not, I still think they stand alone as necessary fixes, but I'll > have to keep digging to find out why you are seeing hangs in g/530. I no longer see hangs, but I do see an interesting pattern in runtime of g/530. I was seeing hangs after only a few minutes of running g/530, and I was using 15 minutes of success to say "git bisect good". Now at 45 minutes of runtime with no hangs. Specifically, I'm testing 0020a190cf3e ("xfs: AIL needs asynchronous CIL forcing"), plus these three patches. If you're interested, I can see which of these three patches actually fixes my hang. I should also test these three patches on top of current 5.17-rc, but I wanted to check they were backportable to current stable first. Of the 120 times g/530 has run, I see 30 occurrences of the test taking 32-35 seconds. I see one occurrence of the test taking 63 seconds. Usually it takes 2-3s. This smacks to me of a 30s timeout expiring. Let me know if you want me to try to track down which one it is.